MedlinePlus Medical Encyclopedia: Allergen

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Allergen

Contents of this page:
Illustrations Definition	Information

Illustrations

Positive reaction to allergen

Definition Return to top

An allergen is a substance that can cause an allergic reaction. Allergens are substances that, in some people, the immune system recognizes as "foreign" or "dangerous" but cause no response for most people.

Information Return to top

Common allergens include:

Bacteria, viruses, and animal parasites
Chemicals
Dust
Drugs (such as antibiotics, serums)
Foods (such as milk, chocolate, strawberries, wheat)
Perfumes
Plants
Pollen
Smoke

See also:

Update Date: 2/15/2007

Updated by: Donald Accetta, MD, MPH, President, Allergy & Asthma Care, PC, Taunton, MA. Review provided by VeriMed Healthcare Network.

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