List of allergens

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.^[4][5]

Buckwheat

Routes

Oral (food), Nasal (inhalation)

Symptoms

Asthma, rhinitis, pruritus, gastrointestinal disturbances, urticaria, angioedema, shock, anaphylaxis^[6]

Allergenicity is highest in Japan and Korea.^[7] It is estimated that buckwheat causes 5% of all immediate-type allergic reaction cases (from food) in Japan.^[8] 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.^[9]

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^[10]

Higher risk of provoking life-threatening reactions compared to most other food allergies. Celery seeds and celeriac are more allergenic than celery stalks.^[11][12] 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.^[13]

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,^[14] avocado, and kiwi are common problems.^[15] Severe allergies to tomatoes have also been reported.^[16][17] Some cross-react with latex allergy.

Stone fruits are highly cross-reactive with one another, as are the rosaceae fruits ^[18][19]

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,^[20] 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.^[21][22]

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 ^[23]

Chemical nature

Protein^[24]

Risk extends to wheat hybrids like triticale.^[25] True wheat allergies are very rare; it is estimated to effect 0.1%-2.2% of individuals depending on region.^[26] 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.^[27] 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.^[28] NCGS is more similar to food intolerances but as of 2021 its pathogenesis is still not well understood.

Legumes

Chemical nature

Seed "storage proteins"

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;^[33] it is seemingly very rare but true prevalence can not be established due to several tests producing high rates of false positives.^[34] Due to a gradual increase in prevalence^[35] and the severity of known reactions it became recognized as the 11th priority allergen by Canada in 2009,^[36] and a top 14 priority allergen by the European Union in 2014.^[37][38]

Rice

Routes

Oral (food), inhalation

Symptoms

Sneezing, runny nose, itching, stomachache, eczema.

Sesame

Routes

Oral (food), skin, inhalation

Symptoms

Potentially systemic anaphylactic responses.^[39][40]

By law, foods containing sesame must be labeled so in European Union, Canada, Australia, and New Zealand.^[39] 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.^[41] 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.^[42] 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)".^[43] Via congressional act, it was declared that food manufacturers must acknowledge sesame as a priority food allergen by the 2023 deadline.^[44]

Tree nut

Routes

Oral (food), inhalation, skin

Symptoms

Anaphylaxis, swelling, rash, hives, sometimes vomiting^[45]

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.

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.^[19] Due to high protein content, egg white allergy is more common than the reverse.^[46] The majority of children with this allergy become tolerant by adulthood.^[47]

Fish

Routes

Oral (food)

Symptoms

Respiratory reactions, Anaphylaxis, oral allergy syndrome, sometimes vomiting

One of three allergies to seafood, not to be conflated with allergies to crustaceans and mollusks.^[48] People with fish allergies have a 50% likelihood of being cross reactive with another fish species,^[49] but some individuals are only allergic to one species, such as; tilapia^[50] salmon,^[48] or cod. A proper diagnosis is considered complicated due to these cross reactivity between fish species and other seafood allergies.^[51] Hazard extends to exposure to cooking vapors or handling.^[52]

Milk

Routes

Oral (food)

Symptoms

Skin rash, hives, vomiting, diarrhea, constipation, stomach pain, flatulence, colitis, nasal congestion, dermatitis, blisters, migraine, anaphylaxis

Protein allergy,^[53] not to be confused with lactose intolerance.^[54] Allergy to cow's milk is the most common food allergy in infants and young children^[46] but most outgrow the allergy in early childhood. Introducing baked cow's milk to allergic patients is associated with accelerated resolution of milk allergy.^[55] Some evidence suggests goat's milk has less allergenic potential than cow's milk^[56] and reduced risk of allergy development if infants are weaned with goat's milk.^[57] Due to adult-onset sensitization it is estimated to be the second most common food allergy in American adults.^[58]

Poultry meat

Routes

Oral (food)

Symptoms

Hives, swelling of, or under the dermis, nausea, vomiting, diarrhea, severe oral allergy syndrome, shortness of breath, rarely anaphylactic shock

Very rare allergies to chicken, turkey, squab, and sometimes more mildly to other avian meats.^[59] Not to be confused with secondary reactions of bird-egg syndrome. The genuine allergy has no causal relationship with egg allergy, nor is there any close association with red meat allergy. Prevalence still unknown as of 2016.^[60]

Red meat

Routes

Oral (food)

Symptoms

Hives, swelling, dermatitis, stomach pain, nausea, vomiting, dizziness, fainting, shortness of breath, anaphylaxis^[61][62]

Allergies to the sugar carbohydrate found in beef, venison, lamb, and pork called alpha-gal. This carbohydrate is made by almost all mammals, with the notable exception of old world monkeys and apes (including humans). Tick bites may inject this substance into the bloodstream; combined with other defense mechanisms against tick bites, this causes the human body to flag alpha-gal as a foreign antigen.^[63]

Allergic reaction to pork is an exception, as it may also be caused by pork-cat syndrome instead of alpha-gal allergy.

Shellfish

Routes

Oral (food), inhalation

Symptoms

Respiratory symptoms, Anaphylaxis, oral allergy syndrome, gastrointestinal symptoms, rhinitis, conjunctivitis

Shellfish allergies are highly cross reactive. Its prevalence is much higher than that of fish allergy. Shellfish allergy is the leading cause of food allergy in U.S adults.^[58] As of 2018 six allergens have been identified to prawn alone; along with crab, it is the major culprit of seafood anaphylaxis.^[48] In reference to it as one of the "Big 8"^[64] or "major 14" allergens it is sometimes specified as a "crustacean shellfish" allergy, or more simply, a "crustacean allergy".^[65][66] Sometimes it is conflated with an allergy to molluscan shellfish but complete tolerance to one but not the other is not uncommon. Most usually, a mono-sensitive individual will experience a crustacean allergy alone with tolerance to mollusks, rather than vice versa.^[48]

The symptoms of an allergic reaction to molluscan shellfish should not be confused with the effects of shellfish poisoning which are a medical reactions that manifest after eating contaminated mollusks from certain areas of the world and lasts for several hours or days after onset.^[67]

Insect sting

Routes

Skin (injection)

Symptoms

Hives, wheezing, possible anaphylaxis

Possible from bee or wasp stings, or bites from mosquitoes or flies like Leptoconops torrens.

Dust mite

Routes

Skin, inhalation

Symptoms

Asthma^[68]

Home allergen reduction may be recommended

Cat

Routes

Inhalation

Symptoms

Sneezing, itchy swollen eyes, rash, congestion, wheezing

Cats express a number of protein allergens, numbered Fel d 1 to Fel d 7. Fel d 1 (from saliva, licked onto fur) and Fel d 4 are the most common culprits.

Dog

Routes

Inhalation

Symptoms

Rash, sneezing, congestion, wheezing, vomiting from coughing, Sometimes itchy welts.

Caused by dander, saliva or urine of dogs, or by dust, pollen or other allergens that have been carried on the fur.^[69] Allergy to dogs is present in as much as 10 percent of the population.^[69]

Human

Tartrazine

Routes

Oral (food), inhalation

Symptoms

Skin irritation, hives, rash

|A synthetic food dye used in processed foods like confections, soft drinks, flavoring syrups, condiments and convenience foods in order to create a potent yellow or bright green coloring. Prevalence of allergenicity is unclear but it is the most likely azo dye to cause hypersensitivity and reactions may occur from ingestion or skin contact. It is possible for some individuals to become desensitized. There is no strong evidence suggesting that tartrazine can cause hypersensitivity or intolerance in non-allergic individuals.

Dimethylaminopropylamine

Routes

Eyelid contact

Symptoms

Eyelid dermatitis

Present as unreacted residue within cocamidopropyl betaine, a mild detergent and foam booster used in liquid soaps and shampoos.

Paraphenylenediamine

Sources

Black hair dye, Color developer, Scuba gear, Henna (may be added to henna but is not found in pure henna)

Cross-reactions

Para-aminobenzoic acid (PABA), Azo dyes, Sulfonamides, Sulfonylureas, Thiazides, Ester anesthetics

Formaldehyde

Sources

Present as unreacted residue in various resins, e.g. tosylamide/formaldehyde resin in nail polish and p-tert-butylphenol-formaldehyde resin (PTBP-FR) in craft glues and commercial leather and rubber products

Symptoms

When exposed to eyelid: eyelid dermatitis

When exposed to foot: Foot dermatitis^{[77][78]: 793}

Glyceryl monothioglycolate

Sources

Permanent hair waving solutions

Routes

Contact with integumentary system.

Tetracycline

Routes

Oral, injection

Symptoms

Many, including: severe headache, dizziness, blurred vision, fever, chills, body aches, flu symptoms, severe blistering, peeling, dark colored urine^[79][80]

Dilantin

Routes

Oral, injection

Symptoms

Many, including: swollen glands, easy bruising or bleeding, fever, sore throat^[81][82][83]

Carbamazepine

Routes

Oral

Symptoms

Shortness of breath, wheezing or difficulty breathing, swelling of the face, lips, tongue etc., hives^[84][85][86]

Also known as brand name "Tegretol".

β-lactams

Sulfonamides

Routes

Oral, injection, skin contact

Symptoms

Urinary tract disorders, haemopoietic disorders, porphyria and hypersensitivity reactions, Stevens–Johnson syndrome toxic epidermal necrolysis

The first broadly effective antibacterials to be used systemically. About 3% of the population are reported as allergic.^[89]

Two regions of the sulfonamide antibiotic chemical structure are implicated in the hypersensitivity reactions associated with the class.

• The first is the N1 heterocyclic ring, which causes a type I hypersensitivity (true allergy) reaction.
• The second is the N4 amino nitrogen that, in a stereospecific process, forms reactive metabolites that cause either direct cytotoxicity or immunologic response.

The nonantibiotic sulfonamides lack both of these structures.^[90]

NSAIDs

Non-steroidal anti-inflammatories (Ibuprofen, Aspirin, etc.)^[91]

Symptoms

Many, including: swollen eyes, lips, or tongue, difficulty swallowing, shortness of breath, rapid heart rate^[92]

Radiocontrast

Routes

Intervenous injection

Symptoms

Anaphylactoid reactions and contrast-induced nephropathy (the latter is not related to allergy)

Local anesthetics

Symptoms

Urticaria and rash, dyspnea, wheezing, flushing, cyanosis, tachycardia^[93]

Sulfite

Routes

Oral (food)

Symptoms

Hives, rash, redness of skin, headache (particular frontal), burning behind eyes, asthma-like breathing difficulties, anaphylaxis

Sulfites (also spelled "sulphites") are used as a preserving agents in many different foods, such as raisins, dried peaches, various other dried fruit, canned or frozen fruits and vegetables, wines, vinegars and processed meats. Allergy appears to be very rare in the general population but it is still often considered to be one of the top 10 food allergies.^[25] It is debated whether reaction to sulfites is a true allergy.^[94]

Water

Symptoms

Epidermal itching, swelling of the oral cavity after drinking water, anaphylaxis (in severe cases)^{[95][96][97][98][99]}

Strictly aquagenic pruritus or aquagenic urticaria, but cold water may also cause cold urticaria

Metals

The following metal products may cause allergic contact dermatitis:

• Nickel (nickel sulfate hexahydrate), also may cause dyshidrotic eczema^[100][101]
• Gold (gold sodium thiosulfate)
• Chromium
• Cobalt chloride

Perfume

Symptoms

Itchy eyes, runny nose, sore throat, headaches, muscle/joint pain, asthma attack, wheezing, chest pain, blisters

Cosmetics

Routes

Skin contact, eye contact

Symptoms

Contact dermatitis,^[102] irritant contact dermatitis, inflammation, redness,^[103] conjunctivitis,^[104] sneezing

Other vaguely-defined allergens

• Photographic developers
• Fungicide

Cold stimuli

Symptoms

Hives, itching