POLLEN

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Definition

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

Common allergens include:

• Bacteria, viruses, and animal parasites
• Chemicals
• Dust
• Drugs (such as antibiotics or medications you put on your skin)
• Foods (such as milk, chocolate, strawberries, wheat)
• Perfumes
• Plants
• Pollen
• Smoke

See also:

• Allergies
• Allergic reaction
• Food allergy
• Allergy to drugs
• Antigen
• Antibody

Reviewer Info: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc. , 02/19/2009