List of allergens

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.