Allergy - Types, Signs & Symptoms, Test & Diagnosis, Prevention & Treatment

Created by philiHealth | | Infections & Diseases | Endocrine DiseasesRespiratory Conditions

Definition of Allergy

What are allergies?

Allergies, also known as allergic diseases, are a number of conditions caused by hypersensitivity of the immune system to typically harmless substances in the environment. Allergens may cause an allergic reaction when they come in contact with skin or the eye, when they are inhaled, eaten, or are injected. An allergic reaction can occur as part of a seasonal allergy. Or an allergic reaction can be triggered by taking a drug, eating certain foods, or breathing in dust or animal dander. These diseases include hay fever, food allergies, atopic dermatitis, allergic asthma, and anaphylaxis. Symptoms may include red eyes, an itchy rash, sneezing, a runny nose, shortness of breath, or swelling. Food intolerances and food poisoning are separate conditions.

The immune system is responsible for the identification and destruction of foreign substances that enters the body. Normally the immune system acts as the body's defense against disease-causing microorganisms and substances. However for some people, the immune system mistakes perfectly harmless substances for germs and in response, it releases certain compounds to destroy the perceived "enemy". This results to allergic reaction. Some people may show allergic reaction to one substance, but others may manifest allergic reaction to many substances. Early exposure to potential allergens may be protective. Treatments for allergies include the avoidance of known allergens and the use of medications such as steroids and antihistamines. In severe reactions injectable adrenaline (epinephrine) is recommended. Allergen immunotherapy, which gradually exposes people to larger and larger amounts of allergen, is useful for some types of allergies such as hay fever and reactions to insect bites. Its use in food allergies is unclear.

Allergy is by far the most common non-infectious disease, especially among the young. It affects anywhere between 10 and 25 % of the worldwide population, both children and adults. In the developed world, about 20% of people are affected by allergic rhinitis, about 6% of people have at least one food allergy, and about 20% have atopic dermatitis at some point in time. Depending on the country about 1–18% of people have asthma. Anaphylaxis occurs in between 0.05–2% of people. Rates of many allergic diseases appear to be increasing. More than 50 million peoplealone in the United States have an allergic reaction each year. They’re the sixth-leading cause of long-term illness in the United States.

What is an allergic reaction?

The job of a healthy immune system is to recognize foreign substances and summon resources, such as white blood cells, to destroy them. Many substances that enter the body are harmless, and in nonallergic persons, the body would not normally mount a reaction; however, in individuals with allergies, exposure to an allergen causes the immune system to react, sometimes quite violently, which results in a variety of signs and symptoms experienced by the allergic individual. The severity of the reaction will help you determine when to seek urgent care for allergies.

An allergic reaction is the way your body responds to an allergen. If you have allergies, the first time you encounter a specific allergen, your body responds by creating immunoglobulin E (IgE). Your immune system makes antibodies to form IgE. IgE antibodies bind to mast cells (allergy cells) that live in your skin, respiratory tract (airways) and the mucus membrane in the hollow organs that connect to each other from your mouth to your anus (gastrointestinal or GI tract). The antibodies find the allergens in your body and help remove them by taking them to the mast cell (allergy cell), where they attach to a special receptor. This causes the allergy cell to release histamine. Histamine is what causes your allergy symptoms. Allergic reactions with immediate effects are the result of antibody-antigen responses (i.e., they are the products of ß-cell stimulation). These can be divided into four basic types:

Type I (immediate IgE-mediated):

Type I reactions, which include hay fever, insect venom allergy, and asthma, involve the class of antibodies known as immunoglobulin E (IgE). IgE molecules are bound to mast cells, which are found in loose connective tissue. When enough antigen has bound with the IgE antibodies, the mast cells release granules of histamine and heparin and produce other agents such as leukotrienes. These potent chemicals dilate blood vessels and constrict bronchial air passages. Histamine is responsible for the visible symptoms of an allergic attack, such as running nose, wheezing, and tissue swelling. A severe, often fatal, type I allergic reaction is known as anaphylaxis. The predisposition of a person to type I allergic reactions is genetically determined. The best protection against such allergies is avoidance of the offending substance. Antihistamine drugs are often used to give temporary relief. Another helpful measure is desensitization, in which increasing amounts of the antigen are injected over a period of time until the sufferer no longer experiences an allergic response.

Type II (cytotoxic):

Type II reactions result when antibodies react with antigens that are found on certain “target” cells. The antigens may be natural components of healthy cells, or they may be extrinsic components induced by drugs or infectious microbes. The resultant antigen-antibody complex activates the complement system, a series of potent enzymes that destroy the target cell.

Type III (immune complex-mediated):

Type III reactions result when a person who has been strongly sensitized to a particular antigen is subsequently exposed to that antigen. In a type III reaction, the antigen-antibody complex becomes deposited on the walls of the small blood vessels. The complex then triggers the complement system, which produces inflammation and vascular damage. Unlike type I reactions, type II and type III reactions are not dependent on a genetic predisposition. Avoidance of known allergens is the best protection against such reactions.

Type IV (delayed cell-mediated):

Type IV, also called "dalayed", allergic reactions are caused by the actions of T cells, which take longer to accumulate at the site where the antigen is present than do B-cell antibodies. The allergic responses appear 12 to 24 hours or more after exposure to an appropriate antigen. A common delayed allergic reaction is contact dermatitis, a skin disorder. The rejection of transplanted organs is also mediated by T cells and thus may be considered a delayed allergic response.


Due to epithelial defects, some people develop allergies due to enhanced permeability to antigens from infectious microbes and other stressors into the skin, digestive tract, and lungs. Epithelium-derived cytokines favor the switching of the ß cell isotype class to IgE. Then, IgE binds to the effector cells' surface, such as basophils and mast cells, via Fc epsilon (Fcε) R1, high-affinity IgE receptors, causing sensitization. In sensitized individuals, ensuing exposure to allergens leads to the release of de novo–synthesized histamine, prostaglandins, etc. These manifest as bronchoconstriction, eosinophilic infiltration, and muscle contraction.

Up to 95% of asthma cases are acquired genetically; similarly, up to 91%, 71%, and 82% of cases of allergic rhinitis, atopic dermatitis, and food allergy, respectively, have roots in genetics. Some genes associated with allergic diseases are filaggrin, ovo-like transcriptional repressor 1 (OVOL1), and interleukin 33 (IL-33), involved in skin barrier function, epidermal differentiation, epithelia-derived alarmins, respectively. Other examples include antigen presentation gene, human leukocyte antigen (HLA)-DQ; T helper cells, TH1, TH2, and regulatory T cells (Treg) gene regulation IL-4 and forkhead box P3 (Foxp3).

A loss of function mutation of the filaggrin gene damages the epithelial layer exacerbating many allergic diseases. Two chemical pollutants, Sodium Dodecyl Sulfate (SDS) and Sodium Dodecyl Benzene, present in laundry and dishwasher detergents, shampoos, et cetera., damage the lung and skin epithelium, even at 1:100,000 dilution. However, heritable genetics alone cannot explain the surge in many allergic diseases. Several studies have shown increased allergies among migrants who moved from a region with a low prevalence to an area with a higher prevalence of atopic diseases, suggesting the role of the earth’s climate changes in allergic diseases. It gave rise to the suggesting that increases in allergy represent a lack of exposure to commensal microbes that evolved concurrently with humans inhabiting their skin, gut, and respiratory tract. Examples include helminths, Helicobacter pylori, and the hepatitis A virus, for which humans had natural immune tolerance.


Acute response:

In the early stages of allergy, a type I hypersensitivity reaction against an allergen encountered for the first time and presented by a professional antigen-presenting cell causes a response in a type of immune cell called a TH2 lymphocyte; a subset of T cells that produce a cytokine called interleukin-4 (IL-4). These TH2 cells interact with other lymphocytes called B cells, whose role is production of antibodies. Coupled with signals provided by IL-4, this interaction stimulates the B cell to begin production of a large amount of a particular type of antibody known as IgE. Secreted IgE circulates in the blood and binds to an IgE-specific receptor (a kind of Fc receptor called FcεRI) on the surface of other kinds of immune cells called mast cells and basophils, which are both involved in the acute inflammatory response. The IgE-coated cells, at this stage, are sensitized to the allergen.

If later exposure to the same allergen occurs, the allergen can bind to the IgE molecules held on the surface of the mast cells or basophils. Cross-linking of the IgE and Fc receptors occurs when more than one IgE-receptor complex interacts with the same allergenic molecule, and activates the sensitized cell. Activated mast cells and basophils undergo a process called degranulation, during which they release histamine and other inflammatory chemical mediators (cytokines, interleukins, leukotriene, and prostaglandins) from their granules into the surrounding tissue causing several systemic effects, such as vasodilation, mucous secretion, nerve stimulation, and smooth muscle contraction. This results in rhinorrhea, itchiness, dyspnea, and anaphylaxis. Depending on the individual, allergen, and mode of introduction, the symptoms can be system-wide (classical anaphylaxis), or localized to particular body systems; asthma is localized to the respiratory system and eczema is localized to the dermis.

Late-phase response:

After the chemical mediators of the acute response subside, late-phase responses can often occur. This is due to the migration of other leukocytes such as neutrophils, lymphocytes, eosinophil and macrophages to the initial site. The reaction is usually seen 2–24 hours after the original reaction. Cytokines from mast cells may play a role in the persistence of long-term effects. Late-phase responses seen in asthma are slightly different from those seen in other allergic responses, although they are still caused by release of mediators from eosinophil and are still dependent on activity of TH2 cells.

Allergic contact dermatitis:

Although allergic contact dermatitis is termed an "allergic" reaction (which usually refers to type I hypersensitivity), its pathophysiology actually involves a reaction that more correctly corresponds to a type IV hypersensitivity reaction. In type IV hypersensitivity, there is activation of certain types of T cells (CD8+) that destroy target cells on contact, as well as activated macrophages that produce hydrolytic enzymes.


The allergic diseases, hay fever and asthma, have increased in the Western world over the past 2–3 decades. Increases in allergic asthma and other atopic disorders in industrialized nations, it is estimated, began in the 1960s and 1970s, with further increases occurring during the 1980s and 1990s, although some suggest that a steady rise in sensitization has been occurring since the 1920s. The number of new cases per year of atopy in developing countries has, in general, remained much lower.

Food allergies have become increasingly prevalent in industrialized/westernized nations over the last 2-3 decades. An estimated 15 million people currently have food allergies in the United States. In 1997, 0.4% children in the United States were reported to have peanut allergy, yet this number markedly rose to 1.4% in 2008. In Australia, hospital admission rates for food-induced anaphylaxis increased by an average of 13.2% from 1994-2005. One possible explanation for the rise in food allergy is the hypothesis, which suggests that non disease causing organisms, such as helminths, could protect against allergy. Therefore, reduced exposure to these organisms, particularly in developed countries, could have contributed towards the increase. Children of East Asian or African descent who live in westernized countries were reported to be at significantly higher risk of food allergy compared to Caucasian children. Several studies predict that Asia and Africa may experience a growth in food allergy prevalence as the lifestyles there become more westernized.

Although genetic factors govern susceptibility to atopic disease, increases in atopy have occurred within too short a time frame to be explained by a genetic change in the population, thus pointing to environmental or lifestyle changes. Several hypotheses have been identified to explain this increased rate, increased exposure to perennial allergens due to housing changes and increasing time spent indoors, and changes in cleanliness or hygiene that have resulted in the decreased activation of a common immune control mechanism, coupled with dietary changes, obesity and decline in physical exercise. The hygiene hypothesis maintains that high living standards and hygienic conditions exposes children to fewer infections. It is thought that reduced bacterial and viral infections early in life direct the maturing immune system away from TH1 type responses, leading to unrestrained TH2 responses that allow for an increase in allergy.

Changes in rates and types of infection alone however, have been unable to explain the observed increase in allergic disease, and recent evidence has focused attention on the importance of the gastrointestinal microbial environment. Evidence has shown that exposure to food and fecal-oral pathogens, such as hepatitis A, Toxoplasma gondii, and Helicobacter pylori (which also tend to be more prevalent in developing countries), can reduce the overall risk of atopy by more than 60% and an increased rate of parasitic infections has been associated with a decreased prevalence of asthma. It is speculated that these infections exert their effect by critically altering TH1/TH2 regulation. Important elements of newer hygiene hypotheses also include exposure to endotoxins, exposure to pets and growing up on a farm.

Where are Allergens?

Allergens may be inhaled, ingested (eaten or swallowed), applied to the skin, or injected into the body either as a medication or inadvertently by an insect sting. The symptoms and conditions that result depend largely on the route of entry and the type of allergen. The chemical structure of allergens affects the route of exposure. Airborne pollens, for example, tend to have little effect on the skin. They are easily inhaled and will thus cause more nasal and respiratory symptoms with limited skin symptoms. When allergens are swallowed or injected, they may travel to other parts of the body and provoke symptoms that are remote from their point of entry. For example, allergens in foods may prompt the release of mediators in the skin and cause hives.

The specific protein structure is what determines the allergen's characteristics. Cat protein from the Felis domesticus (the domesticated cat), is the predominant cat allergen. Each allergen has a unique protein structure leading to its allergic characteristics.

    Who do allergies affect?

    Allergies can affect anyone. You’re more likely to have or develop allergies if your biological parents have allergies. Allergies can develop at any age, but most food allergies begin at a young age, and many are outgrown. Environmental allergies can develop at any time. The initial exposure or sensitization period may even begin before birth. Individuals can also outgrow allergies over time. It is not fully understood why one person develops allergies and another does not, but there are several risk factors for allergic conditions. Risk factors for allergy can be placed in two general categories, namely host and environmental factors:

    • Host factors include heredity, sex, race, and age, with heredity being by far the most significant. However, there have been recent increases in the incidence of allergic disorders that cannot be explained by genetic factors alone.
    • Four major environmental candidates are alterations in exposure to infectious diseases during early childhood, environmental pollution, allergen levels, and dietary changes.

    Family history, or genetics, plays a large role, with a higher risk for allergies if parents or siblings have allergies. There are numerous other risk factors for developing allergic conditions. Children born via Cesarean section have a higher risk of allergy as compared to children who are delivered vaginally. Exposure to tobacco smoke and air pollution increases the risk of allergy. Boys are more likely to be allergic than girls. Allergies are more common in westernized countries, and less common in those with a farming lifestyle. Timing of exposures to antigens, use of antibiotics, and numerous other factors, some of which are not yet known, also contribute to the development of allergies. This complicated process continues to be an area of medical research.

    The parts of the body that are prone to allergic symptoms include the eyes, nose, lungs, skin, and gastrointestinal tract. Although the various allergic diseases may appear different, they all result from an exaggerated immune response to foreign substances in sensitive individuals.


    Allergic diseases are strongly familial: identical twins are likely to have the same allergic diseases about 70% of the time; the same allergy occurs about 40% of the time in non-identical twins. Allergic parents are more likely to have allergic children and those children's allergies are likely to be more severe than those in children of non-allergic parents. Some allergies, however, are not consistent along genealogies, parents who are allergic to peanuts may have children who are allergic to ragweed. It seems that the likelihood of developing allergies is inherited and related to an irregularity in the immune system, but the specific allergen is not.

    The risk of allergic sensitization and the development of allergies varies with age, with young children most at risk. Several studies have shown that IgE levels are highest in childhood and fall rapidly between the ages of 10 and 30 years. The peak prevalence of hay fever is highest in children and young adults and the incidence of asthma is highest in children under 10.


    Allergic diseases are caused by inappropriate immunological responses to harmless antigens driven by a TH2-mediated immune response. Many bacteria and viruses elicit a TH1-mediated immune response, which down-regulates TH2 responses. The first proposed mechanism of action of the hygiene hypothesis was that insufficient stimulation of the TH1 arm of the immune system leads to an overactive TH2 arm, which in turn leads to allergic disease. In other words, individuals living in too sterile an environment are not exposed to enough pathogens to keep the immune system busy. Since our bodies evolved to deal with a certain level of such pathogens, when they are not exposed to this level, the immune system will attack harmless antigens and thus normally benign microbial objects, like pollen, will trigger an immune response.

    The hygiene hypothesis was developed to explain the observation that hay fever and eczema, both allergic diseases, were less common in children from larger families, which were, it is presumed, exposed to more infectious agents through their siblings, than in children from families with only one child. The hygiene hypothesis has been extensively investigated by immunologists and epidemiologists and has become an important theoretical framework for the study of allergic disorders. It is used to explain the increase in allergic diseases that have been seen since industrialization, and the higher incidence of allergic diseases in more developed countries. The hygiene hypothesis has now expanded to include exposure to symbiotic bacteria and parasites as important modulators of immune system development, along with infectious agents.

    Epidemiological data support the hygiene hypothesis. Studies have shown that various immunological and autoimmune diseases are much less common in the developing world than the industrialized world and that immigrants to the industrialized world from the developing world increasingly develop immunological disorders in relation to the length of time since arrival in the industrialized world. Longitudinal studies in the third world demonstrate an increase in immunological disorders as a country grows more affluent and, it is presumed, cleaner. The use of antibiotics in the first year of life has been linked to asthma and other allergic diseases. The use of antibacterial cleaning products has also been associated with higher incidence of asthma, as has birth by caesarean section rather than vaginal birth.


    Chronic stress can aggravate allergic conditions. This has been attributed to a T helper 2 (TH2)-predominant response driven by suppression of interleukin 12 by both the autonomic nervous system and the hypothalamic–pituitary–adrenal axis. Stress management in highly susceptible individuals may improve symptoms.

    Climate change:

    The current research also highlighted the role of changes in the environmental conditions or climate in altering the metaexposome, leading to more allergic diseases. Indeed, human exposure to anthropogenic pollutants in soil, air, and water increased in the past few decades, and so did their exposure to antibiotics and processed foods. Concomitantly, their exposure to beneficial microbes decreased.

    Humans have triggered around 1°C temperature increase since preindustrial times leading to global warming increasing more over time, with unprecedented consequences. Allergy and immunology science lies at an intersection where it is crucial to protect planetary biodiversity while protecting human health, especially of high-risk populations, children, pregnant women, and aboriginal peoples. Few buildings in poor areas have air conditioning or adequate ventilation to reduce smoke and pollution exposure. Many children play in schoolyards for most of the day, exposing themselves to dust and pollen, increasing the odds of developing allergic rhinitis.


    Next comes the role of the microbiome in disrupting the epidermal barrier. For instance, Staphylococcus aureus secretes proteases and toxins in some areas of the skin of diseased individuals, stimulating TH2 cytokines, such as IL-4. Other bacteria associated with the allergic disease are Clostridium difficile, Escherichia coli, Haemophilus, and Streptococcus species.

    Studies have also shown that cutaneous microbial composition shapes adaptive immunity to commensals in neonates. These gut bacteria activate intestinal IL-10–secreting ß cells for immune tolerance and mucosal homeostasis, and any disruptions to them have health implications. Furthermore, infections from respiratory viruses, e.g., Respiratory Syncytial Virus (RSV) in younger infants whose lungs are under development could lead to an increased risk of asthma. There is enough data evidence that a third of infants hospitalized for bronchiolitis develop asthma later.

    Other environmental factors:

    There are differences between countries in the number of individuals within a population having allergies. Allergic diseases are more common in industrialized countries than in countries that are more traditional or agricultural, and there is a higher rate of allergic disease in urban populations versus rural populations, although these differences are becoming less defined. Historically, the trees planted in urban areas were predominantly male to prevent litter from seeds and fruits, but the high ratio of male trees causes high pollen counts.

    Alterations in exposure to microorganisms is another plausible explanation, at present, for the increase in atopic allergy. Endotoxin exposure reduces release of inflammatory cytokines such as TNF-α, IFNγ, interleukin-10, and interleukin-12 from white blood cells (leukocytes) that circulate in the blood. Certain microbe-sensing proteins, known as Toll-like receptors, found on the surface of cells in the body are also thought to be involved in these processes.

    Gut worms and similar parasites are present in untreated drinking water in developing countries, and were present in the water of developed countries until the routine chlorination and purification of drinking water supplies. Recent research has shown that some common parasites, such as intestinal worms (e.g., hookworms), secrete chemicals into the gut wall (and, hence, the bloodstream) that suppress the immune system and prevent the body from attacking the parasite. This gives rise to a new slant on the hygiene hypothesis theory, that co-evolution of humans and parasites has led to an immune system that functions correctly only in the presence of the parasites. Without them, the immune system becomes unbalanced and oversensitive. In particular, research suggests that allergies may coincide with the delayed establishment of gut flora in infants. However, the research to support this theory is conflicting, with some studies performed in China and Ethiopia showing an increase in allergy in people infected with intestinal worms. Clinical trials have been initiated to test the effectiveness of certain worms in treating some allergies.

    Types of Allergies and What Cause Allergies

    People can be allergic to almost anything. Many people suffer an allergic reaction after being exposed to certain perfumes, shampoos, detergents, cleaning agents, or creams. It can be very difficult to identify the culprit because we use so many chemicals in our daily lives. The following are some of the most common allergies:

    Food allergy:

    Food allergies affect up to 10% of the worldwide population, and they are currently more prevalent in children (~8%) than adults (~5) in western nations. In several industrialized countries, food allergies affect up to 10% of children. In the developed world, about 4% to 8% of people have at least one food allergy. Many people are allergic to certain foods; some are merely sensitive and do not experience a true immune response. Sensitivity may occur when a person lacks the necessary enzyme to break down a certain protein, as in lactose (dairy) intolerance, which can lead to stomach pain or cramping. In a true food allergy, eating the food will trigger an immune response, leading to allergic symptoms such as swelling of the airway (which can result in difficulty breathing) or rash. Several chemicals are consequently released after consuming an allergic food. These substances are responsible for allergic reaction symptoms. Though almost any food can trigger an allergic reaction, certain foods are the leading causes of food allergies. Gluten allergy is widely noticed in people. Food allergies arise when the immune system, the body’s line of defence against infection, misinterprets food proteins as a danger. Allergy symptoms are frequently minor, but they can also be very dangerous.

    A wide variety of foods can cause allergic reactions, but 90% of allergic responses to foods are caused by: cow's milk, (casein - a protein found in milk), soy, eggs, wheat, fish, shellfish, wheat and tree nuts (including almonds, brazil nuts, cashews, coconuts, hazelnuts, macadamia nuts, pecans, pistachios, pine nuts, and walnuts), which are referred to as "the big eight".

    In April of 2021, US President Joe Biden signed the Faster Act into law. This landmark food allergy law recognizes Sesame as the ninth mandatory food label allergen. It also encourages research that will improve the quality of life for food allergy families, and that could potentially lower the rates of future food allergies.

    Other food allergies, like peanuts, some fruits and vegetables and sulfites, affecting less than 1 person per 10,000 population, may be considered "rare". The use of hydrolyzed milk baby formula versus standard milk baby formula does not appear to change the risk. Although peanut allergies are notorious for their severity, peanut allergies are not the most common food allergy in adults or children. Severe or life-threatening reactions may be triggered by other allergens, and are more common when combined with asthma. Peanut allergies are not the most common food allergy in adults or children. Severe or life-threatening reactions may be triggered by other allergens, and are more common when combined with asthma. Peanut allergies can sometimes be outgrown by children. Egg allergies affect one to two percent of children but are outgrown by about two-thirds of children by the age of 5. The sensitivity is usually to proteins in the white, rather than the yolk. Milk-protein allergies are most common in children. Approximately 60% of milk-protein reactions are immunoglobulin E-mediated, with the remaining usually attributable to inflammation of the colon. Some people are unable to tolerate milk from goats or sheep as well as from cows, and many are also unable to tolerate dairy products such as cheese. Roughly 10% of children with a milk allergy will have a reaction to beef. Beef contains small amounts of proteins that are present in greater abundance in cow's milk. Lactose intolerance, a common reaction to milk, is not a form of allergy at all, but rather due to the absence of an enzyme in the digestive tract.

    Allergens can be transferred from one food to another through genetic engineering, however genetic modification can also remove allergens. Little research has been done on the natural variation of allergen concentrations in unmodified crops.

    Here is the list of the common food items that cause food allergy:

    Please note that this is a list of food items that some people may be allergic to. It is in no way a list of food items to avoid unless you have shown an allergy to it. Allergens vary from person to person and food item to food item. However, if you see someone developing serious symptoms after consuming any of these food items, take it seriously and seek out help if symptoms are worsening.

    • Soya beans and products made from it - Soy protein allergy is extremely common in children. This can cause itching, rashes and raised reddish areas. 
    • Egg and products made from it - Usually in children below 16 years. Can cause stomach pain and itchy rashes.
    • Peanuts and food made using it - One of the most common, yet most dangerous food allergies. People can develop shortness of breath and excessive itching.
    • Cow’s milk and products made from it - Whey and casein are important proteins in cow’s milk. This usually presents as tingling and itching around the mouth and swelling of the mouth.
    • Wheat and wheat products - Proteins like globulin, gluten, albumin and gliadin present in wheat cause reactions in about 1% of people.
    • Shellfish and its preparations - Protein called tropomyosin can cause itching, hives and skin rashes
    • Nuts like almonds, pecans, walnuts, cashews, pistachios, hazelnut and brazil nuts - are very common affecting about 5% of the population. They can cause itching, swelling and rashes.
    • Fish and fish products - Allergic reactions are usually against parvalbumin proteins present in them. This can lead to itching, congestion or stomach ache.
    • Meat and meat products -  Usually the allergy is to red meat sources with symptoms like indigestion, stomach pain, and congestion.
    • Raw fruits and vegetables -  Fruits and vegetables have some allergic proteins which do not denature and break down when they are consumed raw.
    • Histamine, containing food - Wine, fermented food, dry fruit, cheese etc.
    • Sulfite additives or naturally present sulfites in aged cheese and grapes.
    • Gluten-containing food items.

    Medication allergy:

    Certain medications can cause an allergic reaction. The medicines may be herbal, over-the-counter. Many people are allergic to penicillin, this means their bodies react inappropriately to the presence of the antibiotic in their bloodstream and trigger an immune response. About 10% of people report that they are allergic to medications; however, 90% turn out not to be. Serious allergies only occur in about 0.03%. That include:

    • Penicillin, allopurinol and related antibiotics.
    • Antibiotics containing sulfonamides (sulfa drugs)
    • Nonsteroidal anti-inflammatory drugs (NSAIDs, such as Aspirin and Ibuprofen).
    • Anticonvulsants and/or muscle relaxants drugs.
    • Insulin (especially animal sources of insulin).
    • Substances containing iodine, such as x-ray contrast dyes (these can cause allergy-like reactions)
    • Chemotherapy drugs.

    Insect allergy:

    Allergy caused by insect bites, stings or bug faeces inside the house, that belongs to the hymenoptera order of insects. Typically, insects which generate allergic responses are either stinging insects or biting insects. Stinging insects inject venom into their victims, whilst biting insects normally introduce anti-coagulants, which is a toxic substance. The severity of the reactions can range from minor to fatal. The trigger for the allergic response may be the venom from a sting or fluid from a bite. The insects can cause reactions at any time of the year. They may cause asthma to flare up. Insects sometimes leave behind materials in the home that cause allergic reactions, they are (caddis flies, lake flies, cockroaches, midges).

    • Stinging insects are: paper wasps, honeybees, bumblebees (occasionally), sweat bees (infrequent), hornets, yellow jackets, fire ants (commonly cause anaphylaxis), harvester ants (less common cause of anaphylaxis).
    • Biting insects are: mosquitoes, blackflies, horseflies, deer flies, kissing bugs, bed bugs, fleas, ticks.

    Many people confuse the normal symptoms that occur after being stung with an allergic reaction, but an allergic reaction to an insect sting is often very severe, with symptoms like swelling around the lips, eyes, and tongue; difficulty breathing; itching, cramping, or severe numbness; and dizziness or lack of consciousness, and will require a visit to the nearest health facility.

    Inhalants allergy:

    Inhalant allergies are airborne substances that you inhale (breathe in). In the air we breathe, aside from oxygen, the air contains a wide variety of particles, including allergens.

    • Common outdoor allergens and irritants include: pollen (grass, trees, weeds), mold spores, fungi, smoke, smog, ozone, car emissions, factory emissions, dust.
    • Common indoor allergens and irritants include: animal dander (such as dogs, cats, horses, guinea pigs), dust mites, mold, fragrances, household chemicals, candle smoke, fireplace smoke, cockroach saliva or excrement, cigarette smoke, fuel-burning heaters.
    • Inhalant allergies can also be triggered by volatile organic compounds, or VOCs.3: These chemicals, which are released as gases, can be found in a variety of household products: cleaning supplies, bug repellant, car products, fuel, dry-cleaned clothing, carpeting, crafting supplies, pesticides, paint, paint stripper.

    They include allergens that may affect you throughout the year, perennial allergens and seasonal allergens.

    Perennial allergens include:

    • Pets: Nearly a third of Americans with allergies are allergic to cats and dogs. And twice as many people have cat allergies than dog allergies. Still, sensitivity to dog allergens can be a major cause of allergic symptoms (and even severe manifestations such as asthma) in susceptible individuals, and it is thought that up to 20% of the population in Western countries exhibits some kind of allergy to dogs. Proteins in an animal’s fur, skin (dander), urine (pee), saliva (spit) or dead skin cells are most likely to cause allergies as they can be shed frequently. Pet dander can trigger an allergic reaction at any time of year, but it is more prevalent during winter when people spend more time inside. Although many breeds, including poodles and Portuguese water dogs, are claimed as hypoallergenic dogs, evidence from scientific studies indicates that no dog breeds are truly allergy-free. Compared to dogs, cats are more likely to trigger an allergic reaction. Although cat dander allergies are frequently to blame, cats also have several other allergens on their bodies and saliva. That’s right, cat allergies can be brought on by the saliva that the cat uses to groom itself because it contains allergen-causing proteins. Consulting an allergist is best if an individual suspects that they may be allergic to animals. Dogs are prone to getting into various places, and their fur tends to collect proteins, dander and pollen. Pinpointing the cause of your allergies can be difficult when an animal lives in your home. That’s because homes contain other allergens, such as dust mites, which could cause similar symptoms. It’s important to see an allergist to confirm a pet allergy. It can be hard to admit that the pet you love is causing health issues. Many people choose to endure symptoms rather than get rid of their pet. If you’re determined to live with Fluffy, you can take steps to minimize the symptoms of your allergy. Genetics appear to have a role in the development of allergies, meaning that you’re more likely to experience them if you have family members who are also allergic. Your immune system makes antibodies to fight off substances that might hurt your body, like bacteria and viruses. In a person who has allergies, the immune system mistakes an allergen for something harmful and starts making antibodies to fight it. This is what causes allergy symptoms such as itching, runny nose, skin rashes, and asthma. Pet allergen particles can be carried on clothes, circulate in the air, settle in furniture and bedding, and stay behind in the environment carried on dust particles.
    • Molds: Mold allergy, whose prevalence has significantly increased in the last 20 years, is one of the most common allergy types today. Molds are tiny fungi (plural of fungus). They have spores that float in the air, like pollen, increasing as temperatures rise in the Spring. Common mold allergies include Cladosporium, Alternaria, Stachybotrys, certain varieties of Aspergillus, Penicillium, Chaetomium, Trichoderma, Phoma, and Fusarium. Mold allergy is an uncharacteristic allergic response to mold spores. When someone has a mold allergy, their immune system overreacts when exposed to mold at work, home or outside. Mold allergies can be tough to outrun. The fungus can grow in your basement, in your bathroom, in the cabinet under your sink where a leak went undetected, in the pile of dead leaves in your shady backyard, in the field of uncut grass down the road,  musty attics, and in wooded areas. Molds grow in wet or humid indoor and outdoor conditions, and are a hazard in flooded areas. There are roughly 1,000 species of mold, many of which aren’t visible to the naked eye. As tiny mold spores become airborne, they can cause allergic reactions in people who have mold allergies. Most cases of mold allergy are not life-threatening, but they are exhausting and bothersome. However, occasionally an allergy to mold can lead to more serious complications, such as: Allergic bronchopulmonary aspergillosis: most commonly affecting women with asthma or cystic fibrosis, this condition can result in a permanent lung damage, Asthma: Women with mold allergy can be more prone to mold-induced asthma, which can be dangerous if a severe asthma attack occurs, Hypersensitivity pneumonitis: at times, mold spores enter the lungs and cause an inflammation, Allergic fungal sinusitis: it is an inflammation of the sinuses due to mold. Regardless of the severity of mold allergy symptoms, efforts should be put into minimizing exposure to it and preventing further complications. Various allergy tests, as well as a thorough medical history and a physical exam, are helpful in diagnosing and managing mold allergies.
    • Dust mites: Dust mites are tiny bugs, eight-legged relatives of spiders  that are found in all households. They are few microns in size and cannot be seen with the naked eye. Males dust mites can live over a month, while female dust mites can live up to 90 days. They thrive in environments with a relative humidity of 70-80% and temperature of 20-25°C. They live in dust and the fibers of household objects, such as pillows, mattresses, carpets and upholstery. Dust mites feed on shed human skin flakes and hence found mostly on bedding, upholstered furniture and carpets. On an average day, one person may shed 1.5 grams of dead skin cells, which can feed up to one million dust mites at a time. They thrive in warm, humid environments and hence common in Indian homes. While you can find dust mites all over the world, these creatures tend to favor hot and humid climates. Since they can burrow themselves deep into cloth fibers, they can also travel with you when you move or are on a vacation or business trip. Dust mites themselves are allergenic, meaning they can cause allergies. They also leave behind skin and fecal matter that may also trigger allergies.
    • Cockroaches: Just like cats, dogs, or pollen, cockroaches can cause allergies. Cockroaches are reddish-brown insects that are 1.5 to 2 inches long. The National Pest Management Association reports that 63% of homes alone in the United States contain cockroach allergens. In urban areas, that number rises to between 78% and 98% of homes. An allergist can evaluate whether you’re allergic to cockroaches. Enzymes in proteins found in cockroaches are thought to cause allergic reactions in humans. The proteins in their feces (poop), spit, eggs and dead body parts can cause allergic reactions. These proteins are found in the saliva and excrement of cockroaches. They can easily spread through homes, much like dust. Cockroach allergies are one of the most common worldwide indoor allergies. They can affect both adults and children, though children are known to be most susceptible. Despite this, people may not realize they have them. Research on cockroach allergies only began in the 1960s.

    Seasonal allergies include pollens:

    Seasonal allergies, commonly known as hay fever, are a cluster of somatic reactions triggered by pollen and mold spores. These allergens activate the body’s immune system, causing a reaction. Pollinating trees like birch and elm, grasses, and flowering plants like ragweed are the most common triggers of seasonal allergies that appear as a fine dust on surfaces or float in the air. Tree pollens generally appear in the spring, while weed pollens generally appear in the fall.  However, IgE antibody allergy testing can determine the exact cause. A pollen allergy is one of the most prevalent outdoor allergies in the world because of how widespread it is. Statistically, one in every seven individuals worldwide has a pollen allergy.

    • Trees: Early flowering species like alder, birch, hazel and ash have pollen that is particularly allergenic. Allergy to birch pollen is more prevalent.
    • Grasses: The Poaceae, also known as grasses, are primarily to blame for causing allergies to grass pollen.
    • Weeds: Ragweed and mugwort are two weeds that are very allergenic.

    Seasonal allergies, also known as hay fever or allergic rhinitis, can start at any age, but are usually identified early on and can subdue as you get older. Allergy season typically starts in early spring and lasts until the first frost in autumn. At this time of year, trees and grasses release pollen into the air. Pollen counts are higher on hot, dry, windy days and lower after a rainfall or at night.

    • Tree pollination: April to early June
    • Grass pollination: mid-May to mid-July
    • Weed pollination: mid-August to end of September
    • Molds: midsummer through fall

    Latex allergy:

    It is an allergy caused by contact to latex materials. Common latex materials that cause allergic reaction are: rubber bands, carpet backing, hospital and dental equipment, rubber gloves, balloons, condoms. In a latex allergy, your immune system identifies latex as a harmful substance and triggers certain antibodies to fight it off. The next time you’re exposed to latex, these antibodies tell your immune system to release histamine and other chemicals into your bloodstream, producing a range of allergy signs and symptoms. The more times you are exposed to latex, the more strongly your immune system is likely to respond. This is called sensitization. Latex can trigger an IgE-mediated cutaneous, respiratory, and systemic reaction. Latex allergies aren’t very common. Up to 6% of the general population and 8 to 12% of healthcare workers have a latex allergy. You may have an allergy if you are experiencing common latex allergy symptoms. A latex reaction can become life-threatening if left untreated.

    In a hospital study, 1 in 800 surgical patients (0.125 %) reported latex sensitivity, although the sensitivity among healthcare workers is higher, between 7 and 10%. Researchers attribute this higher level to the exposure of healthcare workers to areas with significant airborne latex allergens, such as operating rooms, intensive-care units, and dental suites. These latex-rich environments may sensitize healthcare workers who regularly inhale allergenic proteins.

    Latex and Banana sensitivity may cross-react. Furthermore, those with latex allergy may also have sensitivities to Banana, Avocado, Kiwi, Apples, Melons, Papaya, Chestnuts, Carrots, Celery, Tomatoes, Potatoes and Nuts. These people often have perioral itching and local urticarial. Only occasionally have these food-induced allergies induced systemic responses. Researchers suspect that the cross-reactivity of latex with these plants occurs because latex proteins are structurally homologous with some other plant proteins.

    Latex allergy can occur in these ways: Direct contact: The most common cause of latex allergy involves touching latex-containing products, including latex gloves, condoms and balloons. Inhalation: Latex products, especially gloves, release latex particles, which you can breathe in when they become airborne. The amount of airborne latex from gloves differs greatly depending on the brand of glove used.

    Certain people are at greater risk of developing a latex allergy:

    • People with spina bifida. The risk of latex allergy is highest in people with spina bifida, a birth defect that affects the development of the spine. People with this disorder often are exposed to latex products through early and frequent health care. People with spina bifida should always avoid latex products.
    • People who undergo multiple surgeries or medical procedures. Repeated exposure to latex gloves and medical products increases your risk of developing latex allergy.
    • Health care workers: If you work in health care, you’re at increased risk of developing a latex allergy.
    • Rubber industry workers. Repeated exposure to latex may increase sensitivity.
    • Other employees who work in an occupation that uses latex gloves, such as a salon, food service industry, tattoo parlor, hair stylists, automotive repair facility, and police or fire stations, are also at risk for sensitivities.
    • Children who need multiple surgeries are also more likely to develop latex allergies.
    • People with a personal or family history of allergies. You’re at increased risk of latex allergy if you have other allergies, such as hay fever or a food allergy or they’re common in your family.

    Allergic rhinitis (Hay fever):

    Rhinitis is the general term for inflammation of the mucous membrane found in the nose. This inflammation causes excess amounts of mucus to be generated, usually resulting in a runny nose or post-nasal drip. 

    Allergic Rhinitis is a type of rhinitis that is caused by an allergic response in the body. Symptoms of can include a runny nose, sneezing, itchy eyes, itchy nose, and congestion. The materials that trigger this allergic response are called allergens, and these can be found both outdoors and indoors. When outdoor allergens are the culprit, allergic rhinitis is called hay fever or seasonal allergies. Common outdoor allergens are the pollens from trees, grasses, and weeds, as well as molds that are found on plants and in the soil. These allergens are highly affected by changing weather conditions.

    Perennial allergies are those that last year-round. They are caused by common indoor allergens like animal dander, the remnants of cockroaches, dust mites, and indoor molds.

    Non-allergic rhinitis is rhinitis caused by pollution, smoke, strong smells, particles in the air, weather changes, or similar irritants. It can also occur as a result of a thyroid disorder, pregnancy, or as a side effect of certain medications. Non-allergic rhinitis can cause symptoms year-round, including nasal congestion.

    Non-allergic Rhinitis Eosinophilia Syndrome (NARES) is characterized by the presence of eosinophils (specific blood cells seen in allergy) in nasal secretions, but negative allergy skin tests. Symptoms and medical treatment are similar to allergic rhinitis. Two factors that affect this condition are environmental changes and nasal polyps.

    Rhinitis medicamentosa is a type of rhinitis that results from the overuse of non-prescription nose sprays that work by constricting blood vessels in the lining of the nose. This kind of rhinitis is best treated by stopping the use of the nasal spray that has caused the problem, though this solution may temporarily result in severe congestion. It is recommend alternative treatments, such as a saline nasal spray or topical corticosteroids to help you through this transition.

    Structural rhinitis is a form of rhinitis that is a result of structural abnormalities in the nose, specifically the septum, the cartilage in your nose that separates the right and left sides. These abnormalities can be something that you were born with, such as small nasal passages, or the result of an injury, such as a broken nose. Structural rhinitis occurs year-round and can result in increased congestion in only one nostril.

    Nasal Polyps are growths on the mucus membrane of the nose that can cause symptoms of rhinitis, especially congestion. Polyps can also interfere with your ability to smell or cause recurrent sinusitis. Polyps generally begin between 20 and 40 years old, can cause year-round symptoms, and may be related to aspirin sensitivity and asthma.

    Plants that cause hay fever are trees, grasses, and ragweed. Their pollen is carried by the wind. (Flower pollen is carried by insects and does not cause hay fever.) Types of plants that cause hay fever vary from person to person and from area to area. The amount of pollen in the air can affect whether hay fever symptoms develop or not.

    • Hot, dry, windy days are more likely to have a lot of pollen in the air.
    • On cool, damp, rainy days, most pollen is washed to the ground.

    Hay fever and allergies often run in families. If both of your parents have hay fever or other allergies, you are likely to have hay fever and allergies, too. The chance is higher if your mother has allergies. Most people with hay fever have allergic reaction to grass and oilseed rape pollens, which appear from April to August each year. People who are sensitive to pollen from hazel, yew, elm and alder may develop allergy symptoms from January to April, and people allergic to nettles and other weeds can be affected from April to mid-September. Many individuals have a combination of both seasonal and perennial allergies. Allergic rhinitis is common and affects up to 30% of the population, and may be seasonal, due to pollens (i.e. “hayfever”), or persistent, for example due to house dust mite, cats, dogs, or other pets. People often perceive this as a persistent cold.

    In 1819, an English physician, John Bostock, first described hay fever by detailing his own seasonal nasal symptoms, which he called "summer catarrh". The condition was called hay fever because it was thought to be caused by "new hay".

    Allergic conjunctivitis:

    Our eyes are widely exposed to allergens in the outside environment. Children with an underlying tendency of allergy develop eye inflammation caused by an allergic reaction to substances or allergens. The inside of the eyelids and the covering of the eyeballs have a membrane called the conjunctiva. The conjunctiva is susceptible to irritation from allergies. Allergic conjunctivitis is usually associated with other allergies like allergic nose or allergic rhinitis and asthma. Allergic conjunctivitis can have a lot of impact on the quality of life of a child.

    Allergic asthma:

    It is presented in about 6 out of 10 cases of asthma, is one of the most common types. Allergic asthma is basically airway passage inflammation due to various allergens. It is caused when your airway passages become so sensitive to particular allergens that your body starts to show allergic reactions. Childhood asthma is usually triggered by allergens more than adulthood asthma due to the immune system being weak during childhood.

    Allergies and asthma often occur together. The same substances that may trigger your hay fever symptoms like pollen, dust mites and pet dander may also cause your asthmatic signs and symptoms. Skin or food allergies can cause asthma symptoms in some people. This is known as allergic asthma or allergy-induced asthma.

    Allergic asthma is a risk factor for human cardiovascular diseases. Asthma is an allergic airway disease in which type 2-mediated inflammation has a pathogenic role. Cardiovascular diseases (CVDs) are type 1-dominant inflammatory diseases in which type 2 cytokines often have a protective role. However, clinical studies demonstrate that allergic asthma and associated allergies are essential risk factors for CVD, including coronary heart diseases, aortic diseases, peripheral arterial diseases, pulmonary embolism, right ventricular dysfunction, atrial fibrillation, cardiac hypertrophy and even hypertension. Mast cells, eosinophils, inflammatory cytokines and immunoglobulin (Ig)E accumulate in asthmatic lungs and in the injured heart and vasculature of patients with CVD.

    A 2022 study published in Nature Cardiovascular Research by Junli Guo, Yuanyuan Zhang, Tianxiao Liu, Bruce D. Levy, Peter Libby & Guo-Ping Shi, show that many anti-asthmatic therapies affect the risk of CVD. As such, allergic asthma and CVD may share common pathogenic mechanisms. Preclinical investigations indicate that anti-asthmatic drugs have therapeutic potential in certain CVDs. In this Review, we discuss how asthma and allied allergic conditions may contribute to the prevalence, incidence and progression of CVD and vice versa.

    Allergic skin condition:

    Various conditions affecting the skin can cause itchiness and rashes, but only some are related to an allergy. There are many types of skin allergies and rashes that can cause itchiness and inflammation. However, not all rashes that itch are related to skin allergies. Insect bites and autoimmune conditions, along with fungal, bacterial, and viral infections, can all cause an itchy rash. While there may be other reasons for your rash, allergic reactions are still among the most common causes of skin rashes.

    Atopic dermatitis (Eczema):

    Atopic dermatitis, more commonly known as eczema, frequently occurs in young children, although it may start in young adults, and can continue into adult life. This rash occurs where a person scratches. In infancy, the rash most often occurs on the cheeks and/or scalp. Older children and adults typically have the rash in the skin folds of the elbows and behind the knees, although it may also occur on the ​face, neck, hands, feet, and back. The rash is red, often flakes or oozes, and has small blisters or bumps. There are often excoriations, or areas of broken skin, from aggressive scratching. In cases where eczema does not improve with emollient (moisturizer) use alone, a thorough evaluation by an allergist-immunologist is warranted. Prescription creams and ointments or systemic medications may be required to control severe eczema. In rare cases allergic triggers (including contact allergens and environmental exposures) may also be identified that upon removing may significantly improve rash.

    Urticaria (Hives):

    Urticaria, commonly referred to as hives, is an itchy rash that can occur at any age. This rash appears as raised red bumps of various shapes and sizes and typically lasts for only minutes to hours. While it can be very itchy, a person with hives will generally not scratch enough to break the skin and cause bleeding. Urticaria can be acute (lasting less than six weeks) or chronic (lasting more than six weeks).

    Angioedema (Swelling):

    The swelling that sometimes goes along with urticaria is called angioedema. It often involves the lips, eyes, hands, and feet. In cases where angioedema presents at the same time as urticaria, the angioedema usually feels itchy. In cases where angioedema presents without urticaria, it can feel itchy or it may burn, sting, or cause a tingling sensation instead. In rare cases, severe swelling that blocks the ability to breathe can develop. This is a medical emergency known as anaphylaxis, which can be life-threatening.

    Signs and Symptoms of Allergies

    Allergic signs and symptoms:

    Many allergens such as dust or pollen are airborne particles. In these cases, symptoms arise in areas in contact with air, such as eyes, nose, and lungs. For instance, allergic rhinitis, also known as hay fever, causes irritation of the nose, sneezing, itching, and redness of the eyes. Inhaled allergens can also lead to increased production of mucus in the lungs, shortness of breath, coughing, and wheezing. Aside from these ambient allergens, allergic reactions can result from foods, insect stings, and reactions to medications like aspirin and antibiotics such as penicillin. Insect stings, food, antibiotics, and certain medicines may produce a systemic allergic response that is also called anaphylaxis; multiple organ systems can be affected, including the digestive system, the respiratory system, and the circulatory system. Depending on the rate of severity, anaphylaxis can include skin reactions, bronchoconstriction, swelling, low blood pressure, coma, and death. This type of reaction can be triggered suddenly, or the onset can be delayed. The nature of anaphylaxis is such that the reaction can seem to be subsiding, but may recur throughout a period of time.

    Not everyone will respond to the same allergen in the same way. Some allergic reactions are relatively mild and localized, while others are severe and affect many different body systems. Here’s a list of symptoms typically observed in individuals suffering from allergies, the following examples of how different body systems can be affected:

    Affected organ

    Common signs and symptoms
    NoseSwelling of the nasal mucosa (allergic rhinitis), runny or stuffy nose, sneezing (hay fever, rhinitis), nasal congestion.

    Allergic sinusitis.


    Redness and itching of the conjunctiva (allergic conjunctivitis, watery), redness under the lids and of the eye overall, swelling of the membranes, excessive watering of the eyes.

    Mouth and throat

    Swelling around the mouth and throat, tongue, lips, postnasal drip (throat clearing), tingles or itches in the mouth.


    Sneezing, coughing, bronchoconstriction, wheezing and dyspnea, shortness of breath, chest tightness, trouble breathing and heavy wheezing, sometimes outright attacks of asthma, in severe cases the airway constricts due to swelling known as laryngeal edema.


    Feeling of fullness, itchy ears, possibly pain, and impaired hearing due to the lack of eustachian tube drainage.


    Rashes, such as eczema and hives (urticaria), itchy and swelling skin, dry skin associated with significant itching, involvement of the face, the front of elbows, and behind knees, though the rash can occur anywhere, intense itching (typically not painful), raised, red, welts that resolve over hours to a day, swelling, scaling, blistering, crusting, welts (particularly of the lips, face, hands, and feet).

    Gastrointestinal tract

    Abdominal pain, nausea, bloating, vomiting, diarrhea.

    All body

    Lowering of blood pressure (which can lead to shock in severe reactions), light headedness, weakness and anaphylaxis, frequent dizziness, rapid heart rate, swelling/soreness of the throat, hoarseness, anxiety or a sense of impending doom (in anaphylaxis), fatigue, collapse or loss of consciousness, in severe cases may cause death.

    Food allergy symptoms:

    A food allergy is an abnormal response to a food triggered by your body's immune system. The food allergy type, its intensity, and the body’s response depends on your physiology. However, a handful of common symptoms have been identified that may indicate your allergy to particular food items. An allergic reaction occurs within minutes of eating the food and symptoms can be severe. In adults, the foods that most often trigger allergic reactions include: fish, shellfish, peanuts, and tree nuts, such as walnuts. Problem foods for children can include eggs, milk, peanuts, tree nuts, soy, and wheat.

    Symptoms may include:

    • Itching or or funny sensation in and around your mouth including your throat, tongue or face.
    • Swelling (angioedema) of lips, tongue, eyelids, or the whole face.
    • Difficulty swallowing.
    • Runny or congested nose.
    • Hoarse voice.
    • Bloating, nausea and vomiting or the feeling of vomiting, diarrhea, or abdominal cramps and pain.
    • Lightheadedness, fainting and dizziness.
    • Itching and swelling all over your body (generalized pruritus).
    • Itching and swelling in just one certain part of your body (localized pruritus).
    • Itchy skin, and swelling of the skin during hives (urticaria).
    • A raised, red rash that itches.
    • Tightening of the throat and trouble breathing.
    • Food allergies rarely cause respiratory (asthmatic) reactions, rhinitis, hay fever symptoms like sneezing or wheezing, difficulty breathing and/or shortness of breath.
    • Drop in blood pressure.
    • When you have food allergies, you must be prepared to treat an accidental exposure. Wear a medical alert bracelet or necklace and carry an auto-injector device containing epinephrine.

    A dangerous reaction called anaphylaxis may happen in very rare cases. Serious danger regarding allergies can begin when the respiratory tract or blood circulation is affected. If you have an IgE-mediated food allergy, it may present as any one of the above symptoms or a combination of the above symptoms. This occurs suddenly and deteriorates rapidly, it usually takes about 30 minutes of ingesting a food you’re allergic to. In some cases, however, onset of symptoms may be delayed for hours. The symptoms usually start with a swollen tongue and difficulty breathing, wheezing and cyanosis. Poor blood circulation leads to a weak pulse, pale skin and fainting. When symptoms are related to a drop in blood pressure, the person is said to be in anaphylactic shock. Anaphylaxis occurs when IgE antibodies are involved, and areas of the body that are not in direct contact with the food become affected and show symptoms. This is a medical emergency. If you notice someone reacting adversely to food quickly, reach out to the emergency department immediately.

    Food allergies develop more easily in people with the atopic syndrome, a very common combination of diseases: allergic rhinitis and conjunctivitis, eczema, and asthma. Those with asthma or an allergy to peanuts, tree nuts, or seafood are at greater risk for anaphylaxis. The syndrome has a strong inherited component; a family history of allergic diseases can be indicative of the atopic syndrome.

    Medication allergy symptoms:

    A drug allergy occurs when your body’s immune system becomes sensitized to a substance in a medication, perceives it as a foreign invader, and releases chemicals to defend against it, a buildup of the drug that causes toxicity to the skin, a drug makes the skin more sensitive to sunlight, or interaction of two or more drugs. In some cases, drug rashes can be idiopathic, meaning there’s no known direct cause. An allergic reaction to drugs can affect any part of your body.

    Most side effects of drugs are not due to an allergic reaction caused by the formation of IgE antibodies. For example, aspirin can cause hives or trigger asthma without involving the immune system. Many people confuse an unpleasant, but not serious, side effect of a medicine (such as nausea) with a drug allergy. Most drug allergies cause minor skin rashes and hives. These symptoms may occur right away or hours after receiving the drug. Serum sickness is a delayed type of reaction that occurs a week or more after you are exposed to a medicine or vaccine. Drug allergies can also be associated with low blood counts.

    Common symptoms of a drug allergy include:

    • Skin rashes or eruptions (mostly appear the same on both sides of your body)
    • Hives
    • Itchy skin or eyes
    • Swelling of the lips, tongue, or face
    • Wheezing
    • Bleeding

    Symptoms of anaphylaxis (a potentially life-threatening reaction) include:

    • Abdominal pain or cramping
    • Confusion
    • Difficulty breathing with wheezing or hoarse voice
    • Dizziness, fainting, lightheadedness
    • Hives over different parts of the body
    • Nausea and vomiting, diarrhea
    • Rapid pulse or sensation of feeling the heart beat (palpitations)

    Some of the most common types of drug rashes:

    • Exanthematous rashes: Are considered the most common type of drug rashes, accounting for about 90% of cases. You may notice small, raised or flat lesions on reddened skin. In some cases, the lesions may blister and fill with pus. Possible causes of exanthematous drug rashes include: penicillins, sulfa drugs, cephalosporins, antiseizure drugs, allopurinol.
    • Urticarial rashes: Hives (urticaria) are the second most common type of drug rash. This type of rash consists of small, pale red bumps that can connect and form larger patches. They can become very itchy. Possible causes of urticarial drug rashes include: NSAIDs, ACE inhibitors, antibiotics (especially penicillin), general anesthetics.
    • Photosensitivity reactions: Refers to reactions worsened by sun exposure. Certain drugs can make your skin extra sensitive to ultraviolet light, causing a subsequent itchy sunburn if you go outside without wearing sunscreen and protective clothing. Possible causes of photosensitivity reactions include: certain antibiotics (including tetracycline), sulfa drugs, antifungals, antihistamines, retinoids (such as isotretinoin), statins, diuretics, some NSAIDs.
    • Erythroderma: Is a potentially life threatening condition that causes nearly your entire skin to become itchy and red. Your skin may grow scaly within several days. You may also experience a fever, with your skin feeling hot to the touch. Possible causes of erythroderma include: sulfa drugs, penicillins, antiseizure drugs, chloroquine, allopurinol, isoniazid, certain underlying health conditions can also cause erythroderma (such as psoriasis and atopic dermatitis). Erythroderma can become serious and life threatening. Seek immediate medical attention if you think this is the type of rash you have.
    • Stevens-Johnson Syndrome (SJS) and Toxic Epidermal Necrolysis (TEN): Are considered the same condition, but there’s a slight difference between the two. SJS involves less than 10% of your body and TEN involves more than 30%. Both are marked by large, painful blisters. Each one can also cause large areas of the top layer of your skin to come off, leaving raw, open sores. Possible causes of SJS or TEN include: sulfa drugs, antiseizure drugs, some NSAIDs, allopurinol, nevirapine. These are serious reactions that can be life threatening. They both require immediate medical attention.
    • Anticoagulant-induced skin necrosis: Certain blood thinners, such as warfarin, can cause anticoagulant-induced skin necrosis. At first, you might notice your skin turns red and painful. As necrosis progresses, the tissues beneath your skin die. However, your risk of this reaction tends to be higher at the start of taking a very high dose of a new blood thinner. Anticoagulant-induced skin necrosis is a serious reaction that requires immediate medical attention.
    • Drug Reaction with Eosinophilia and systemic Symptoms (DRESS): This is a rare type of drug rash that can be life threatening. You may not notice symptoms for 2 to 6 weeks after starting a new drug. This type of rash looks red, often starting on the face and upper body. Additional symptoms are severe and can involve the internal organs, such as: fever, swollen lymph nodes, facial swelling, burning pain and itchy skin, flu-like symptoms, organ damage. Possible causes of DRESS include: anticonvulsants, allopurinol, abacavir, minocycline, sulfasalazine, proton pump inhibitors. This is a very serious reaction that requires immediate medical attention.

    Your personal risk for developing a drug rash may be higher if you have certain risk factors, such as being older and being female. You may also consider discussing other risk factors with your doctor: a viral infection and taking an antibiotic, a weakened immune system due to an underlying condition or other drug or even cancer.

    Insect allergy symptoms:

    For most people, insect stings or bites are quite harmless. But in someone with an insect venom allergy they can trigger severe reactions, and occasionally even be life-threatening. Insect sting allergies occur when your immune system overreacts to the venom in insect stings, in people with this type of allergy. Around 2% of the population react to insect stings/bites with discomfort in areas other than where stung or bitten. Allergic reactions are most often triggered by bee and wasp venom. The site of the sting or bite may swell up badly. With insect stings a large local reaction may occur (an area of skin redness greater than 10 cm in size). It can last one to two days. It often causes bad pain, and itching or burning. This reaction may also occur after immunotherapy. In most cases the allergic reactions occur immediately after the sting or bite, but occasionally hours afterwards. An anaphylactic reaction may also possibly fade away initially, before returning within 8 hours. The symptoms can also affect the entire body. This is a so-called anaphylactic reaction. People with an allergy face particular danger if stung or bitten in the mouth or throat. The swelling can narrow the airways and make breathing difficult. However, it is rare that the swelling is so bad that there is a risk of suffocation.

    Your immune system responds to unfamiliar substances with cells that can detect the specific invader. One component of this system is antibodies. They allow the immune system to recognize unfamiliar substances, and play a role in getting rid of them. There are multiple types of antibodies, each with a particular role. One of these subtypes, known as immunoglobulin E (IgE), is associated with the development of allergic reactions. If you have an allergy, your immune system becomes overly sensitized to certain substances. Your immune system mistakes these substances for invaders. In the course of responding to this mistaken signal, the immune system produces IgE antibodies specific to that substance. The first time a person with an insect allergy is stung, the immune system may produce a relatively small amount of IgE antibodies that are targeted toward that insect’s venom. If stung again by the same kind of insect, the IgE antibody response is much more rapid and vigorous. This IgE response leads to the release of histamine and other inflammatory chemicals that cause allergy symptoms.

    Common symptoms of a insect bite or sting allergy include:

    • Swelling at the sting site
    • Swellings to the face or hands
    • Itching over the entire body
    • Hives
    • Wealing (urticaria)
    • Dizziness
    • Nausea
    • Stomach complaints
    • Difficulty in swallowing
    • Cough
    • Difficulty breathing
    • General weakness

    Symptoms of anaphylaxis (a potentially life-threatening reaction) include:

    • Swelling in your face, mouth or throat
    • Difficulty breathing or shortness of breath
    • Wheezing
    • Difficulty swallowing
    • Dizziness
    • Drop in blood pressure
    • Rapid pulse
    • Loss of consciousness
    • Cardiac arrest

    An anaphylactic reaction is a severe allergic reaction that can usually be alleviated by immediate treatment. In case of emergency, an appropriate response is very important, so it can be a good idea for people affected to carry an emergency kit with them.

    Common insect bites and how to identify their symptoms:

    • Tick bite: The best way to identify a tick bite is to find one of the insects attached to you, and they can linger for three to six days as they feed on your blood. Some leave a red spot about the size of a dime, but not everyone exhibits this. Tick bites often occur on warmer parts of the body, like the hairline, armpits, behind the knees, and groin. Tick bites are pretty painless and a bit itchy at first, but dangerous, with more serious symptoms appearing days to weeks after a bite. A bullseye rash signals Lyme disease, but other tick-borne illnesses include ehrlichiosis, anaplasmosis, and tularemia, although the risk for each varies depending on the tick’s species.
    • Spider bite: If you’ve got two tiny puncture marks on your skin (or see a spider crawling away), you are probably dealing with a spider bite. Redness and swelling at the site of the bite are also common. Thankfully, most spiders bite only when provoked. Innocuous spider bites often cause mild pain (like a bee sting) and even itching. But watch out for brown recluses and black widows: The former can cause necrotic lesions, while the latter can bring on muscle spasms, tremors, and nausea. Seek medical help if you suspect a bite from either of these spiders.
    • Mosquito bite: Mosquito bites present as small, puffy, round bumps that are lighter or redder than the surrounding skin. Bites often center around ankles, hairlines, and the backs of knees and necks, and they’re likely to be isolated, not part of a cluster (unless you were hanging out in prime mosquito territory during dawn or dusk). As you most likely know, mosquito bites are painless at first, then very itchy. Some people suffer from “skeeter syndrome”, which causes the bites to grow into painful, swollen welts. Mosquitoes do carry a risk of certain diseases like Denga, West Nile and Zika, so monitor for cold- or flu-like symptoms after a bite.
    • Bed Bug bite: Often confused with mosquito bites, bed bug bites are small, red, puffy bumps that appear in lines or clusters, usually three or more. They can have distinct red marks at their center, and they often appear on exposed skin that touches the bed at night, including the arms, neck, or trunk of the body. With close examination of your room, you can often find the bugs (or their droppings) in your mattress, particularly around the corners, the head end, and the cord that encircles it. Bed bug bites aren’t too painful, but they can be very itchy and swollen. The parasites don’t spread diseases like ticks do; however, they’re difficult to remove and won’t stop biting you until they’re eradicated from your home.
    • Head Lice bite: What they look like: Another too-close-for-comfort pest are head lice, which leave patches of red, abraded spots on the scalp and surrounding skin. Although their bites are small, the body’s reaction to them makes them grow. You might not even see the bites first—the initial giveaway might be tiny lice eggs (a.k.a. nits) first. Lice bites are quite itchy, and an infestation can even feel like something is moving or tickling in the hair (which, to be honest, is what’s happening). This can actually cause trouble sleeping. Sores caused by scratching can also develop easily. The only solution is getting rid of the bugs ASAP.
    • Flea bite: Like bed bug or lice bites, flea bites are red bumps that appear in lines and clusters. They’re distinctively small, and they often have reddish halos surrounding them. Fleas tend to bite around the ankles and in warm places like the knees, groin, and armpits, but honestly, they usually prefer your pets. Flea bites are very itchy, and they might even become sore or painful, causing a rash around the affected skin. Scratching the bites could cause these symptoms to worsen or even lead to infection.
    • Fly bite: There are a few major fly species that bother people in the United States, including deer, horse, stable, and black flies. Bites vary by species and person, but they’re often raised, red bumps or welts. Some might even bleed. Blackfly bites also might swell. More often than not, fly bites are going to hurt. After the pain subsides, some may also become itchy, but most fly bites are innocuous. In rare cases, deer flies can pass on the bacterial disease tularemia, which can cause a painful ulcer, and blackfly bites can lead to a flu-like condition called “blackfly fever”.
    • Sand Fly bite: Sand fly bites are distinct from those of other flies. They can appear alone, but often present in groups of small, red bumps or blisters. Sand Fly bites are generally painful and may start to itch. In certain parts of the world, including the tropics, subtropics, and southern Europe, they can transmit cutaneous leischmaniasis, a parasitic infection that causes skin lesions and ulcers.
    • Chigger bite: Also known as berry bugs or harvest mites, chiggers are those tiny, red mites that are almost invisible to the naked eye. Their bites take the form of flat, red patches or raised, red bumps, and they sometimes might even become blisters or pustules. Chiggers often bite the ankles, wrists, thighs, groin, and waist. Contrary to popular belief, chiggers don’t burrow into your skin or suck blood—but that doesn’t make their bites any less itchy. The severe discomfort can last up to two weeks, but mites don’t spread disease.
    • Ant bites and sting: Some ants can bite and sting. If you’re dealing with an aggressive one, it’s probably a fire ant, which are more common in the southern states. Fire ants, because they’re so lovely, will actually bite you so they can hold themselves against your body—and then proceed to sting you with their backend. The result can cause a pimple-like pustule, although some people don’t react at all. Fire ant stings are very painful due to the potency of their venom, and since ants don’t lose their stingers when they attack, you’ll probably end up with multiple wounds. The inflammation and pain can take days or weeks to go away, and sometimes checking in with a doctor is needed.
    • Bee sting: Bee stings vary from person to person. Some people exhibit only a small, light spot, while others get a larger, red welt. There also might be a white spot at the center where the sting occurred. In the case of a honey bee sting, the barbed stinger is often still attached, which will keep pumping venom into your body until you remove it. Bee stings cause moderate pain, which should subside within a few hours. All insect stings can cause life-threatening allergic reactions, and bee stings are no exception. Monitor your symptoms after a sting and call emergency if you notice the signs of anaphylaxis, including swelling beyond the sting site, tightness in the chest or throat, or trouble breathing.
    • Scabies: Scabies is a skin infestation caused by a mite. Untreated, these microscopic mites can live on your skin for months. They reproduce on the surface of your skin and then burrow into it to lay eggs. This causes an itchy, red rash to form on your skin. The extremely itchy rash may be pimply, made up of tiny blisters, or scaly. After the initial exposure to scabies, it can take 2 to 5 weeks for symptoms to appear. If you've had scabies before, the symptoms usually develop more quickly, often as soon as 1 to 4 days after exposure. The hallmark symptoms of scabies include a rash and intense itching that gets worse at night. Continuous scratching of the infected area can create sores that can become infected. If this occurs, reach out to your doctor; additional treatment with antibiotics for the skin infection may be needed.
    • Wasp sting: Wasp stings can be uncomfortable, but most people, without wasp sting allergies, recover quickly and without complications. Typical wasp stings present as sharp pain, redness, swelling, and itching or burning at the sting site. Often, a raised welt will appear around the sting site. A tiny white mark may be visible in the middle of the welt where the stinger punctured your skin. Usually, the pain and swelling recedes within several hours of being stung. More concerning reactions to wasp stings, that may indicate some level of allergy to the venom, include extreme redness and swelling that increases for two or three days after the sting. Nausea and vomiting can also occur. Most times, these reactions will subside on their own in about a week. You should let your doctor know right away if you have a more concerning reaction after a wasp sting. Some people with more severe allergies to wasp stings may go into anaphylactic shock, which can be life threatening. If you experience any severe swelling of the face, lips, or throat; hives or itching in areas of the body not affected by the sting; breathing difficulties, such as wheezing or gasping; loss of consciousness; nausea or vomiting; or weak or racing pulse, seek emergency medical help immediately.
    • Yellow Jacket sting: Similar to wasps and bees, when a yellow jacket stings you, it pierces your skin with its stinger and injects a poisonous venom that causes sudden pain. After being stung, you may also experience swelling or redness around the sting for a few hours. Fatigue, itching, and warmth around the injection site are also common symptoms people experience after a sting. Some symptoms warrant emergency medical attention. These may include: coughing or wheezing; problems breathing or swallowing, or having tightness in your throat; changes to your skin, such as breaking out into hives; feeling lightheaded or dizzy, or passing out; or vomiting or diarrhea. These symptoms may indicate a severe allergic reaction or anaphylaxis. If you or someone near you exhibits these symptoms, seek emergency medical help immediately.
    • Brown Recluse Spider bite: The brown recluse spider, or violin spider, is about 1-inch long and has a violin-shaped mark on its upper back. It is often found in warm, dry climates and prefers to stay in undisturbed areas such as basements, closets, and attics. It is not an aggressive spider, but will attack if trapped or held against the skin. When the brown recluse bites, it is often painless, then skin reddens, turns white, develops a red “bull’s-eye”, blisters, and becomes painful. Venom from the brown recluse spider usually causes local tissue damage. Moderate to severe pain and itching at the site of the bite is typical and usually occurs 2 to 8 hours after the spider has injected its venom. Rare complications include fever, body aches, nausea, vomiting, hemolytic anemia, rhabdomyolysis, and kidney failure. These bites can be deadly in rare cases. If you suspect that you’ve been bitten by a brown recluse, seek medical care immediately. If you can, bring the spider with you for positive identification.

    Inhalants allergy symptoms:

    Inhalant allergy is more common than you think. Most appear during childhood, but some appear later in life. Very often, it is impossible for us to find out what inhalant we are allergic to, because inhalant allergic reaction usually appears hours after we come in contact with a specific inhalant. Inhalant includes house dust mites, molds, pollen and animals. Inhalant allergy is an adverse reaction that occurs when we come in contact with a specific inhalant. It is driven by our own body’s immune system. In other words, your immune system does not like the inhalant you come in contact with, therefore produces antibodies against these particles, known as immunoglobulin E (IgE). The next time you come in contact with the same inhalant, your immune system will release a huge amount of chemicals into your bloodstream causing an allergic reaction. Even a tiny amount of the inhalant particle can trigger an allergic reaction.

    Although airborne allergies are caused by harmless things, your body identifies these substances as foreign. This leads to your allergy symptoms, like sneezing, congestion, runny nose, and more. Inhalant allergies commonly include indoor allergens, such as dust mites and outdoor allergens, such as pollen and mold. The usual diseases that result from airborne allergens are hay fever, asthma, and conjunctivitis.

    Common symptoms of a inhalants allergy include:

    • Runny and stuffy nose
    • Itchy eyes, nose, mouth, and throat
    • Swollen, red, watery eyes
    • Pressure/fullness in the ears and sinus
    • Loss of smell
    • Facial pain (from nasal congestion)
    • Rash
    • Sneezing
    • Coughing
    • Congestion
    • Lightheadedness
    • Dizziness
    • Headache

    If you have asthma, inhalant allergies can also trigger or worsen your symptoms, including wheezing and shortness of breath.

    Symptoms of anaphylaxis (a potentially life-threatening reaction) include:

    • Swollen tongue and throat
    • Tightening of airway
    • Difficulty in breathing
    • Severe wheezing
    • Drop in blood pressure
    • Rise in pulse rate
    • Severe dizziness
    • Loss of consciousness

    Pet allergy symptoms:

    Pet allergies can show in varying degrees of severity depending on the person. You don’t have to own a pet to be exposed to the allergen. That’s because it can travel on people’s clothes. Pet allergies may not appear for several days if your sensitivity or allergen levels are low. Common signs of a pet allergy usually follow shortly after you come in contact with pet dander, saliva, or urine. The pet allergen that over 90% of people with pet allergies react to comes from pet saliva and skin. It’s found in higher levels on male cats and is transferred to a cat’s fur during grooming. Fatigue is common in untreated allergies, as is an ongoing cough due to postnasal drip. But symptoms such as fevers, chills, nausea, or vomiting should be considered related to an illness rather than allergies. Symptoms of pet allergic reactions can develop in a matter of minutes or as much as a few hours from exposure. Immune reactions can also last anywhere from a few minutes to a few hours depending on how long you were around allergens and what contact you had with a pet.

    If you are pet allergic and pet allergens get into your lungs, the allergens can combine with antibodies and cause symptoms. These can include difficulty breathing, coughing, and wheezing. Furthermore, chronic exposure to dog allergens can lead to allergic sensitization and subsequently contribute to the development of bronchial hyper-reactivity and asthma in children. Pet allergies can cause an acute asthma attack and can be a trigger for chronic asthma. Up to 30% of people with asthma can have a severe attack upon coming into contact with a pet. You should talk to your doctor about a treatment plan if your symptoms become disruptive or uncomfortable.

    Common symptoms of a pet allergy include:

    • Rashes, hives, itching of the skin, (mostly on face, neck, or upper chest)
    • Redness on the skin where a pet has had contact
    • Swollen and blue halo under the skin
    • Sneezing
    • Runny or congested nose (itching of the nose)
    • Watery, itchy or red eyes
    • Itching of the membranes around your eyes and nose (usually leading to eye inflammation)
    • Coughing
    • Irritated palate or throat
    • Facial pain (from nasal congestion)
    • Wheezing
    • Difficulty in breathing
    • Dizziness

    Symptoms of anaphylaxis (a potentially life-threatening reaction) include:

    • Hives, eczema, itchy skin
    • Swollen tongue and throat
    • Tightening of airway (chest tightness or pain)
    • Difficulty in breathing
    • Severe whistling or wheezing
    • Drop in blood pressure
    • Rise in pulse rate
    • Trouble sleeping due to difficulty breathing
    • Severe dizziness
    • Lightheadedness
    • Loss of consciousness

    Mold allergy symptoms:

    Depending on the type of mold and the way an individual was exposed to it, the symptoms may vary. Some people experience mold poisoning symptoms seasonally, while others are affected year-round. When inhaled, mold spores enter the nose and the lungs, and our immune system initiates a full defense response to fight the invader. Some people develop symptoms rather quickly, when others, even under the same conditions, might not experience any symptoms at all. People with existing health problems are more susceptible to mold-related issues. Again, in some people, mold poisoning might be asymptomatic (with no obvious symptoms), while in others, it might cause a variety of problems. By the way, your pets are also affected by mold poisoning.

    People with the chronic respiratory disease might develop mold poisoning symptoms after inhaling just a small amount of mold spores. The more spores inhaled, the worse their condition and symptoms will be. Therefore, people with asthma or obstructive pulmonary disorder need to be on full guard when dealing with mold. If a person is allergic to mold, the reaction for mold exposure might be more intense. It can show itself as a respiratory reaction or on the skin. Because people with allergies are more sensitive, it is important to minimize contact with moldy areas or infected air, as longer exposure can lead to more severe problems. Also, those with immune suppression are at high-risk for developing fungal infections after mold exposure. Even if your immune system normally works well, but you just had the flu, your immune system will likely be weak after fighting the virus.

    Alcohol, smoking, and bad nutrition also suppress your immune system, making you more susceptible to mold poisoning. While mold exposure is universal, symptoms depend on your sensitivity to mold, your exposure to mold, and whether you may be sensitive to other allergens. Mold infections are uncommon, as they don’t occur in people with properly working immune systems. But a person may become more susceptible to mold infections if the immune system is suppressed by medications, diseases, tobacco, or alcohol. People with lung problems or previous conditions are more likely to develop an infection. The symptoms might be more severe if the mold exposure continues. It could also make current health issues worse if not addressed, which includes asthma and lung diseases.

    Common symptoms of a mold allergy include:

    • Stuffy or runny nose and postnasal drip
    • Eye irritation (watering, red eyes, itching)
    • Sore, dry throat
    • Dry cough or sneezing
    • Irritation to the mucous membranes of the mouth, nose and throat
    • Headaches
    • Congestion
    • Skin irritation (rash, hives, skin scaling)

    Symptoms of anaphylaxis (a potentially life-threatening reaction) include:

    • Itchy nose, mouth, and throat
    • Runny nose and nasal congestion
    • Watery and itchy eyes
    • Wheezing and sneezing or difficulty breathing
    • Chronic coughing
    • Wet cough (with mucus or blood)
    • Asthma attacks
    • Chronic congestion
    • Recurrent sinusitis
    • Fever
    • Chest pain
    • Fever
    • Eczema
    • Headache
    • General malaise and chronic fatigue
    • Brain fog (difficulty focusing)

    Symptoms of a mold allergy with allergic rhinitis include:

    • Sneezing
    • Stuffy or runny nose and postnasal drip
    • Coughing
    • Itchy eyes, nose and throat
    • Eye irritation (watering, red eyes, itching)
    • Skin irritation (rash, hives, skin scaling)

    Symptoms of a mold allergy with asthma include:

    • Coughing, wheezing and breathing difficulties
    • Chest tightness
    • Shortness of breath

    Symptoms if you eat food with mold:

    • Nausea
    • Vomiting
    • Diarrhea

    Dust mites allergy symptoms:

    While other bugs you encounter may bite, dust mites themselves don’t actually bite your skin. However, an allergic reaction to these pesky creatures may induce skin rashes. These are often red and itchy in nature. Allergic reactions to dust mites are common and typically caused by inhaling the mites’ skin and fecal matter materials. The common dust mites allergies are atopic eczema or dermatitis, allergic rhinitis, eye allergies and asthma. You may notice wheezing, coughing, and chest pain as a result. Your symptoms may be worse at night when you’re lying down. The more you stay indoors, the more you may be prone to dust mite complications. If you have a dust mite allergy, you may experience symptoms year-round. You may also notice that your symptoms peak during the hot, humid summer months.

    Common symptoms of a dust mites allergy include:

    • Sneezing
    • Coughing
    • Itchy throat
    • Itchy, water eyes
    • Redness in the eyes
    • Stuffy or runny nose
    • Postnasal drip (which may cause a sore throat)
    • Congestion (stuffiness when breathing through the nose)
    • Facial itching
    • Face infection
    • Redness and skin pores opening

    Symptoms of anaphylaxis (a potentially life-threatening reaction) include:

    • Trouble breathing or swallowing
    • Wheezing (a whistling or rattling when breathing) with cough and cold
    • Heaviness in the chest or chest pain
    • Swollen throat
    • Shortness of breath
    • Fainting
    • Rash
    • Facial pressure and pain
    • Blue colored skin bags under the eyes
    • Panic

    Cockroaches allergy symptoms:

    Symptoms of cockroach allergies are similar to those of other common allergies. They’re most similar to symptoms of dust mites, or seasonal allergies. In many cases with cockroach allergens, these symptoms become chronic, lasting beyond typical seasonal allergies. People with cockroach allergies may notice their symptoms last beyond the time seasonal allergies would naturally lessen. They may also occur when dust or mites aren’t present.

    Common symptoms of cockroach allergy include:

    • Coughing, sneezing or wheezing
    • Runny nose or postnasal drip (mucus flows behind your nasal cavity and into your throat)
    • Nasal congestion or sinus infections
    • Ear infections
    • Skin rash
    • Itchy skin, nose, throat, or eyes

    Symptoms of anaphylaxis (a potentially life-threatening reaction) include:

    • Wheezing sound while breathing out
    • Pain in the chest or chest tightness
    • Difficulty in breathing
    • Trouble when sleeping due to coughing, wheezing, or shortness of breath

    Latex allergy symptoms:

    The most prevalent response to latex is an allergic contact dermatitis, a delayed hypersensitive reaction appearing as dry, crusted lesions. This reaction usually lasts 48–96 hours. Sweating or rubbing the area under the glove aggravates the lesions, possibly leading to ulcerations. Anaphylactic reactions occur most often in sensitive patients who have been exposed to a surgeon's latex gloves during abdominal surgery, but other mucosal exposures, such as dental procedures, can also produce systemic reactions.

    The most common reaction to latex is skin irritation (contact dermatitis). It manifests as a rash on the area of skin that touched the latex. It may develop within minutes of exposure to latex. Substances that come into contact with the skin, such as latex, are also common causes of allergic reactions, known as contact dermatitis or eczema. Skin allergies frequently cause rashes, or swelling and inflammation within the skin, in what is known as a "weal and flare" reaction characteristic of hives and angioedema. Naturally occurring latex has been linked in recent years to allergic reactions in people who use such products as latex gloves. The proteins in the latex, which can also become airborne, can cause problems in vulnerable people such as breathing problems and contact dermatitis. Symptoms of a latex allergy can range from mild to severe, depending on the degree of your sensitivity to latex and the amount of latex you come in contact with. Additionally, your allergic reaction can become worse with each latex exposure as your immune system is likely to respond in a stronger way every time. Some allergic reactions, including anaphylactic shock, have been more severe.

    Many health experts have rightly attributed the dramatic increase of allergic reactions to latex in the health care community to the increased use of gloves and other personal protection equipment in light of the AIDS epidemic. Latex is a pervasive substance in many household items, from toys and balloons to rubber bands and condoms.

    Common symptoms of latex allergy include:

    • Stuffy, runny ans itchy nose
    • Respiratory problems (difficulty breathing)
    • Scratchy sneezing, wheezing and cough
    • Scratchy throat
    • Itchy or watering eyes
    • Inflammation of the eyes
    • Dry skin
    • Hives or rash (large bumps on the skin that are itchy)
    • Itching and/or red skin
    • Swelling at the place of contact (usually hands)
    • Eczema or blisters on hands
    • Tingling sensations
    • Low blood pressure
    • Nausea

    Symptoms of anaphylaxis (a potentially life-threatening reaction) include:

    • Asthma-like symptoms such as trouble breathing, wheezing, and chest tightness
    • Noisy breathing
    • Wheeze or cough
    • Swelling and tightness of the throat
    • Drop in blood pressure
    • Chest pain
    • Dizziness or weak
    • Nausea and/or vomiting

    An anaphylactic reaction develops immediately after latex exposure in highly sensitive people, but it rarely happens the first time you’re exposed. A severe allergic reaction (anaphylaxis) is a medical emergency, if not treated quickly. Call your local emergency immediately. Lay the person down. If they have an adrenaline injector and you are able to administer it, do so. Symptoms of anaphylaxis include severe breathing difficulty, dizziness, drop in blood pressure, shock and loss of consciousness. In rare cases, it can even lead to death. Watch for these reactions within minutes of exposure to latex:

    People with high-risk factors for latex allergy include those who have undergone multiple surgical operations, have spina bifida, or are persistently exposed to latex products. If you are vulnerable to latex or have allergies related to it, please notify our office and, by all means, seek medical attention from your family physician.

    Skin allergies symptoms:

    The common reactions of latex sensitive individuals exposed to latex are contact urticaria (hives), angioedema (swelling), allergic contact dermatitis (eczema) and asthma. Skin reactions are less common in today's society, as most health services have switched to non-latex gloves to be on the safe side. Not all latex products are made from natural sources. Products containing man-made (synthetic) latex, such as latex paint, are unlikely to cause a reaction.

    Contact urticaria (hives):

    Contact urticaria usually presents with itching and swelling of the skin at the site of contact with latex. This may, for example, be hands from wearing gloves, genitals from contact with condoms, etc. Urticaria, commonly referred to as hives, is an itchy rash that can occur at any age. This rash appears as raised red bumps of various shapes and sizes. The symptoms usually start within 5-15 minutes after coming into contact with the latex article, although it can be delayed for several hours. While it can be very itchy, a person with hives will generally not scratch enough to break the skin and cause bleeding. Urticaria can be acute (lasting less than six weeks) or chronic (lasting more than six weeks).

    Angioedema (swelling):

    The swelling that sometimes goes along with urticaria is called angioedema. It often involves the lips, eyes, hands, and feet. In cases where angioedema presents at the same time as urticaria, the angioedema usually feels itchy. In cases where angioedema presents without urticaria, it can feel itchy or it may burn, sting, or cause a tingling sensation instead. In rare cases, severe swelling that blocks the ability to breathe can develop. This is a medical emergency known as anaphylaxis, which can be life-threatening.

    Allergic contact dermatitis (eczema):

    Contact dermatitis will resemble eczema or blisters. They are most often found on the back of the hands and mistaken for poison ivy. Allergic contact dermatitis is a skin allergy that occurs after wearing latex gloves or products. Symptoms will begin 24-48 hours after using the gloves. It presents with an itchy, scaly rash, although there may be small blisters if the reaction is acute. The rash will usually last several days to weeks but if exposure to latex continues, the rash will last longer. Contact dermatitis is not generally caused by sensitivity to latex protein but rather to the chemicals used in the manufacture of the latex product, including antioxidants and rubber accelerators e.g. powder inside them, thiuram, carbamates, MBT, etc.

    Immediate-type hypersensitivity requires previous sensitization and is the most potentially dangerous reaction to latex. A common cause for the asthmatic reaction is powdered gloves. The starch powder picks up the latex proteins and when the gloves are removed the powders can then be inhaled or come into contact with the skin on the face where it can cause an allergic reaction. In the most serious allergic reaction, symptoms occur within minutes and involve multiple systems in the body.

    A contact dermatitis rash may look like atopic dermatitis, but the rash is typically located only in the area of contact with the offending substance. In rare cases, symptoms might spread to other areas of the body. Common locations include the face, especially the eyelids, neck, hands, and feet. Contact dermatitis happens when the skin comes into direct contact with a substance that causes a reaction. People react to a variety of chemicals, including cosmetics, hair dye, metals such as nickel, topical medications, and dental materials. An example of contact dermatitis is a rash from poison ivy, which is extremely itchy and appears as blisters that ooze and crust after contact with plants of the Toxicodendron family. Contact dermatitis to metals, such as in jewelry or snaps/buttons/zippers on clothing, commonly occurs on the neck, wrists/hands, piercing holes, and at the waistline. Contact dermatitis can be diagnosed through a patch test, though it can be difficult to determine the point of contact with the allergen.

    Common symptoms of allergic contact dermatitis include:

    • Itching
    • Burning sensation or pain
    • Red bumps that may ooze, drain, or crust
    • Warm, tender skin
    • Scaly, raw, or thickened skin
    • Dry, red, or rough skin
    • Skin inflammation
    • Cuts or rash

    Atopic dermatitis:

    Atopic dermatitis is a type of eczema, and causes your skin to become red and itchy. The American Academy of Dermatology estimates that 1 in 10 people have this condition. Atopic dermatitis is due to a reaction in the skin. The reaction leads to ongoing itching, swelling, and redness. People with atopic dermatitis may be more sensitive because their skin lacks specific proteins that maintain the skin's barrier to water. Atopic dermatitis can be caused by allergies. In some children, food allergies and dust mite allergies play a role in the development of atopic dermatitis.

    Atopic dermatitis, more commonly known as eczema, frequently occurs in young children, although it may start in young adults, and can continue into adult life. This rash occurs where a person scratches. In infancy, the rash most often occurs on the cheeks and/or scalp. Older children and adults typically have the rash in the skin folds of the elbows and behind the knees, although it may also occur on the ​face, neck, hands, feet, and back. The rash is red, often flakes or oozes, and has small blisters or bumps. There are often excoriations, or areas of broken skin, from aggressive scratching. In cases where eczema does not improve with emollient (moisturizer) use alone, a thorough evaluation by an allergist-immunologist is warranted. Prescription creams and ointments or systemic medications may be required to control severe eczema. In rare cases allergic triggers (including contact allergens and environmental exposures) may also be identified that upon removing may significantly improve rash.

    Contact your healthcare provider right away if you have a rash that appears suddenly, spreads quickly, or is accompanied by a fever. You should also seek care if you have a blistering rash near your genitals, on or near your eye area, or in your mouth, or if a rash shows signs of infection.

    The following can make atopic dermatitis symptoms worse:

    • Allergies to pollen, mold, dust mites, or animals
    • Cold and dry air in the winter
    • Colds or the flu
    • Contact with irritants and chemicals
    • Contact with rough materials, such as wool
    • Dry skin
    • Drying out of the skin from taking frequent baths or showers and from swimming
    • Getting too hot or too cold, as well as sudden changes in temperature
    • Perfumes or dyes added to skin lotions or soaps
    • Emotional stress

    Toxins interacting with proteins:

    A non-food protein reaction, urushiol-induced contact dermatitis, originates after contact with poison ivy, eastern poison oak, western poison oak, or poison sumac. Urushiol, which is not itself a protein, acts as a hapten and chemically reacts with, binds to, and changes the shape of integral membrane proteins on exposed skin cells. The immune system does not recognize the affected cells as normal parts of the body, causing a T-cell-mediated immune response. Of these poisonous plants, Sumac is the most virulent. The resulting dermatological response to the reaction between urushiol and membrane proteins includes redness, swelling, papules, vesicles, blisters, and streaking.

    Estimates vary on the percentage of the population that will have an immune system response. Approximately 25% of the population will have a strong allergic response to urushiol. In general, approximately 80 to 90% of adults will develop a rash if they are exposed to .0050 milligrams (7.7×10-5 gr) of purified urushiol, but some people are so sensitive that it takes only a molecular trace on the skin to initiate an allergic reaction.

    Seasonal allergy symptoms:

    Pollen is a common seasonal allergen, as is dust, grass, and oak. Allergic rhinitis, often called hay fever, is a reaction to grains and pollen, as well as other substances, and may occur during a certain season (seasonal) or all year long (perennial). When mold and pollen get released and come in contact with the body, the immune system of people with allergies kicks in. They release chemicals like histamine to fight these foreign particles off, which in turn, causes seasonal allergy symptoms. Symptoms include itchy and watery eyes, nose, and throat, a runny nose, coughing, sneezing, congestion and itchiness.

    Seasonal allergies are also one of the most common triggers for asthma, a chronic respiratory disorder that causes the lung’s mucus membranes and airways to swell up. If not well-managed, allergic asthma can lead to serious complications such as labored breathing and chest pains. Approximately 50% of people with asthma also have pollen allergies, and when the two team up, it can be a serious health concern.

    Many people use over-the-counter or prescription-strength antihistamines to manage their symptoms. However, the allergy season is gradually starting earlier and lasting longer. Taking antihistamines over a prolonged period of time can cause problems. Their effectiveness tends to wane over time, which means people will need to take stronger doses to achieve the same effect. Further, many allergy medicines are not safe to take during pregnancy or breastfeeding. Fortunately, there are many natural, medication-free ways to minimize allergen exposure and reduce symptoms.

    Allergic rhinitis (Hay fever) symptoms:

    When your body comes into contact with an allergen, it releases histamine, which is a natural chemical that defends your body from the allergen. This chemical can cause allergic rhinitis and its symptoms, including a runny nose, sneezing, and itchy eyes. Some people experience symptoms only rarely. This likely occurs when you’re exposed to allergens in large quantities. Other people experience symptoms all year long. Talk to your doctor about possible allergies if your symptoms last for more than a few weeks and don’t seem to be improving.

    Common symptoms of a mold allergy include:

    • Sneezing, often with a runny or clogged nose
    • Coughing and postnasal drip
    • Itchy and watery eyes, nose and throat
    • Red, watery eyes
    • Dark circles under the eyes

    Allergic conjunctivitis symptoms:

    The most common symptoms of allergic conjunctivitis in children are tearing, itching, redness and edema or swelling in the eyes. Other symptoms of allergic conjunctivitis in children are stinging, burning and a clear watery discharge. Some children have seasonal symptoms especially in pollen months while some children have year around symptoms. Vernal keratoconjunctivitis is an advanced stage of disease where the cornea can get involved and requires early and proper diagnosis.

    Allergic asthma symptoms:

    An allergic response occurs when immune system proteins (antibodies) mistakenly identify a harmless substance, such as tree pollen, as an invader. In an attempt to protect your body from the substance, antibodies bind to the allergen. The chemicals released by your immune system lead to allergy signs and symptoms, such as nasal congestion, runny nose, itchy eyes or skin reactions. For some people, this same reaction also affects the lungs and airways, leading to asthma symptoms.

    Common symptoms of an allergic asthma include:

    • Cough
    • Wheezing
    • Shortness of breathe
    • Quick breathing
    • Tightness in chest

    Symptoms of anaphylaxis (a potentially life-threatening reaction) include:

    • Trouble breathing or noisy breathing
    • Difficulty talking more than a few words and/or hoarse voice
    • Wheeze
    • Cough
    • Swelling and tightness of the throat
    • Collapse
    • Light-headedness or dizziness
    • Diarrhea
    • Tingling in the hands, feet, lips or scalp
    • Swelling of tongue
    • Pale and floppy (in young children)


    Allergy due to exercise-induced anaphylaxis develops allergic reaction after doing some strenuous exercise. Anaphylactic shock is an emergent, life-threatening condition that occurs when blood vessels dilate excessively due to an allergic reaction, which causes a significant drop in blood pressure. This can result in inadequate blood flow to the organs in the body. Anaphylactic shock is a potentially life-threatening allergic reaction that can affect a number of organs at the same time. Allergens that typically lead to anaphylaxis are foods, medications, and venom (bee stings). Environmental allergens rarely lead to anaphylaxis, except anaphylaxis can result from allergy shots (subcutaneous immunotherapy). A severe allergic reaction (anaphylaxis) is a medical emergency. Call your local emergency immediately. Lay the person down. If they have an adrenaline injector and you are able to administer it, do so.

    Some or all of the following symptoms may occur:

    • Shortness of breath or wheezing, coughing
    • Hives itching or flushing present in 80%-90% of cases
    • Nasal congestion, runny nose, itchy eyes
    • Hoarseness or tightness in your throat
    • Swelling of the tongue, lips, eyelids, face and/or throat
    • Tingling in scalp, hands, feet, or lips
    • Abdominal discomfort, nausea, vomiting, diarrhea
    • Low blood pressure, leading to lightheadedness, passing out, or shock

    Remember that anaphylaxis is life-threatening; you, therefore, need to seek medical attention immediately. When you have an epinephrine auto-injector, you must use it and possible repeat the process after a few minutes if the symptoms don’t improve. You should also seek medical attention after you receive the shots or if your symptoms don’t stop. That’s because a delayed reaction can likely happen.


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