This is a list of allergies, which includes the allergen, potential reactions, and a brief description of the cause where applicable.
An allergy is a misguided type-I hypersensitivity response triggered by binding of an allergen to immunoglobulin E (IgE) antibodies. Antibody reactions require a molecule of sufficient size. As a result, most allergens are large biomolecules such as proteins and carbohydrates, many of which can be removed or broken down by food processing. A smaller molecule may still become allergenic by binding to a larger molecule to form an epitope of sufficient size; such a small molecule is called a hapten.
This list also includes some other forms of hypersensitivity reactions, especially so-called allergic contact dermatitis (ACD), a type-IV hypersensitivity response. Such a response is not associated with IgE action, but T-cell activation. The prototypic example is Urushiol-induced contact dermatitis.
Allergens are categorized on this page by origin for minimal redundancy. Symptoms typically depend on route of exposure, which is not yet sorted cleanly here.
The World Health Organization and International Union of Immunological Societies (WHO/IUIS) Allergen Nomenclature Sub-Committee maintains a webpage listing every protein (as well as some carbohydrates) that have elicited a confirmed IgE reaction in any human. Readers seeking a more reliable list are advised to visit their website.
Plant
Balsam of Peru
Routes Oral (food), Skin contact Symptoms Redness, swelling, itching, allergic contact dermatitis reactions, stomatitis (inflammation and soreness of the mouth or tongue), cheilitis (inflammation, rash, or painful erosion of the lips, oropharyngeal mucosa, or angles of their mouth), pruritus, hand eczema, generalized or resistant plantar dermatitis, rhinitis, conjunctivitis, and blisters.
Present in many foods, such as coffee, flavored tea, wine, beer, gin, liqueurs, apéritifs (e.g. vermouth, bitters), soft drinks including cola, juice, citrus, citrus fruit peel, marmalade, tomatoes and tomato-containing products, Mexican and Italian foods with red sauces, ketchup, spices (e.g. cloves, Jamaica pepper (allspice), cinnamon, nutmeg, paprika, curry, anise, and ginger), chili sauce, barbecue sauce, chutney, pickles, pickled vegetables, chocolate, vanilla, baked goods and pastries, pudding, ice cream, chewing gum, and candy.
Present in many drugs, such as hemorrhoid suppositories and ointment (e.g. Anusol), cough medicine/suppressant and lozenges, diaper rash ointments, oral and lip ointments, tincture of benzoin, wound spray (it has been reported to inhibit Mycobacterium tuberculosis as well as the common ulcer-causing bacteria H. pylori in test-tube studies), calamine lotion, surgical dressings, dental cement, eugenol used by dentists, some periodontal impression materials, and in the treatment of dry socket in dentistry.
A number of national and international surveys have identified Balsam of Peru as being in the "top five" allergens causing patch test reactions in people referred to dermatology clinics.
Buckwheat
Routes Oral (food), Nasal (inhalation) Symptoms Asthma, rhinitis, pruritus, gastrointestinal disturbances, urticaria, angioedema, shock, anaphylaxis
Allergenicity is highest in Japan and Korea. It is estimated that buckwheat causes 5% of all immediate-type allergic reaction cases (from food) in Japan. Hazard extends to inhalation of milled flour particles (aeroallergen). Irrespective of the nomenclature, it is not a wheaten cereal; the name refers to its viability as a pseudocereal. Relating or conflating buckwheat allergy with wheat allergy or Triticeae hypersensitivities should be avoided.
Celery
Routes Oral (food) Symptoms Abdominal pain, nausea, vomiting, oral allergy syndrome, urticaria, neck or facial swelling, severe asthma symptoms, exercise induced anaphylaxis, potentially fatal anaphylactic shocks
Higher risk of provoking life-threatening reactions compared to most other food allergies. Celery seeds and celeriac are more allergenic than celery stalks. Some individuals become cross-sensitized to other spices and herbs in the parsley family. Prevalence is high among adults in Central Europe. It is estimated that two-fifths of all Swiss food-allergy patients react to celery tubers and nearly a third of severe food allergy reactions in France may be due to celery.
Fruit
Routes Oral (food) Symptoms Mild itching, rash, generalized urticaria, oral allergy syndrome, abdominal pain, vomiting, anaphylaxis
A wide range of fruits may cause allergy. Mango, strawberries, banana, avocado, and kiwi are common problems. Severe allergies to tomatoes have also been reported. Some cross-react with latex allergy.
Stone fruits are highly cross-reactive with one another, as are the rosaceae fruits
Reaction to hot peppers, a kind of botanical berry, is another specific type of fruit allergy.
Garlic
Routes Oral (food) Symptoms Dermatitis, rhinitis, asthma, urticaria, asymmetrical pattern of fissure, thickening/shedding of the outer skin layers, rarely anaphylaxis
Very few garlic allergens have been reported, and garlic allergy has been rarely studied. Some garlic-allergic individuals may cross-react with leek, shallot and onion (other Allium). Garlic that has been heated/cooked is less allergenic than raw garlic.
Oat
Routes Oral (food), inhalation Symptoms Dermatitis, respiratory problems, anaphylaxis
Risk extends to respiratory inhalation. Oat is not a triticeae cereal but it is possible for individuals with gluten-related disorders to be misdiagnosed as having a hypersensitivity to pure oat because cross-contamination is very common in the western world.
Wheat (and other cereals)
Routes Oral (food), inhalation Symptoms Eczema (atopic dermatitis), Hives, asthma, "baker's asthma", hay fever, oral allergy syndrome, angioedema, abdominal cramps, Celiac disease, diarrhea, temporary (3 or 4 day) mental incompetence, anemia, nausea, vomiting and exercise induced anaphylaxis Chemical nature Protein
Risk extends to wheat hybrids like triticale. True wheat allergies are very rare; it is estimated to effect 0.1%-2.2% of individuals depending on region. The allergy does not commonly persist into adolescence. Gluten-free foods are safer for wheat allergic patients but they still may theoretically contain wheat's other allergenic proteins. Wheat allergy symptoms should not be confused with celiac disease, gluten ataxia or non-celiac gluten sensitivity (NCGS). While wheat allergies are "true" allergies, celiac disease and gluten ataxia are an autoimmune diseases. NCGS is more similar to food intolerances but as of 2021 its pathogenesis is still not well understood.
Legumes Chemical nature Seed "storage proteins"
Peanut
Routes Oral (food), inhalation Symptoms Anaphylaxis and swelling, sometimes vomiting
Distinct from tree nut allergy, as peanuts are legumes. Reactions are often severe or fatal.
Includes some cold-pressed peanut oils. Highly refined (hot pressed followed by further treatment) peanut oils contain almost no protein and present minimal risk.
Soy
Routes Oral (food), inhalation Symptoms Anaphylaxis, asthma exacerbation, rhinitis, allergic conjunctivitis, hives, atopic dermatitis, swelling of, or under the dermis, diarrhea, nausea, vomiting
Overall is lower in prevalence than both peanut allergy and cow's milk allergy. However, due to similar protein structures, soya is a common cross-reactive allergen in both peanut-allergic individuals and milk-allergic individuals; especially infants.
Again, highly-refined oil is not allergenic.
Maize
Routes Oral (food), inhalation Symptoms Hives, pallor, confusion, dizziness, stomach pain, swelling, vomiting, indigestion, diarrhea, cough, tightness in throat, wheezing, shortness of breath, anaphylaxis
Often a difficult allergy to manage due to the various food products which contain various forms of maize protein.
Mustard seed
Routes Oral (food), inhalation Symptoms Eczema, Rash, Hives, Facial swelling, Other skin reactions, Oral allergy syndrome, Conjunctivitis, Wheezing, Abdominal pain, Diarrhea, Nausea, Vomiting, Acid Reflux, Dizziness, Asthma, Chest pain, Respiratory problems, Anaphylaxis
Mustard allergy onset is usually in infancy or toddlerhood; it is seemingly very rare but true prevalence can not be established due to several tests producing high rates of false positives. Due to a gradual increase in prevalence and the severity of known reactions it became recognized as the 11th priority allergen by Canada in 2009, and a top 14 priority allergen by the European Union in 2014.
Rice
Routes Oral (food), inhalation Symptoms Sneezing, runny nose, itching, stomachache, eczema.
Sesame
Routes Oral (food), skin, inhalation Symptoms Potentially systemic anaphylactic responses.
By law, foods containing sesame must be labeled so in European Union, Canada, Australia, and New Zealand. Increasing prevalence has led to it being deemed the ninth most common food allergen in the United States in 2019. Highest prevalence by age was among 18-29 year olds and an estimated 80% of all sesame-allergic patients had a comorbid food allergy. In 2018, the US FDA issued a request for information for the consideration of labeling for sesame to help protect people who have sesame allergies. A decision was reached in November 2020 that food manufacturers voluntarily declare that when powdered sesame seeds are used as a previously unspecified spice or flavor, the label be changed to "spice (sesame)" or "flavor (sesame)". Via congressional act, it was declared that food manufacturers must acknowledge sesame as a priority food allergen by the 2023 deadline.
Tree nut
Routes Oral (food), inhalation, skin Symptoms Anaphylaxis, swelling, rash, hives, sometimes vomitingNational Institutes of Health, NIAID Allergy Statistics Hazard extends to exposure to cooking vapors, or handling. Distinct from peanut allergy, as peanuts are legumes.
Pollen
Routes Inhalation, eye contact Symptoms Sneezing, body ache, headache (in rare cases, extremely painful cluster headaches may occur due to allergic sinusitis; these may leave a temporary time period of 1 and a half to 2 days with eye sensitivity), allergic conjunctivitis (includes watery, red, swelled, itchy, and irritating eyes), runny nose, irritation of the nose, nasal congestion, minor fatigue, chest pain and discomfort, coughing, sore throat, facial discomfort (feeling of stuffed face) due to allergic sinusitis, possible asthma attack, wheezing
Latex
Routes Skin contact, mucousal contact Symptoms Contact dermatitis, hypersensitivity
Risk factors for reaction to latex include spina bifida, family history of allergy to latex, or a personal history of allergies, asthma, or eczema.
Urushiol
Routes Skin contact Symptoms Contact dermatitis
One of the most common allergies. Urushiol is found in various plants, most notably plants in the Toxicodendron genus, such as poison oak and poison ivy.
Animal
Egg (chicken, birds)
Routes Oral (food) Symptoms Anaphylaxis, swelling, sometimes flatulence and vomiting
Egg yolk and egg white contain different proteins. An allergic individual may not have any reaction to consuming food only prepared with egg yolk and not egg white, or vice versa. Due to high protein content, egg white allergy is more common than the reverse. The majority of children with this allergy become tolerant by adulthood.
Fish
Routes Oral (food) Symptoms Respiratory reactions, Anaphylaxis, oral allergy syndrome, sometimes vomiting