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Allergen

An allergen is a substance that can cause an allergic reaction. In some people, the immune system recognizes allergens as foreign or dangerous. As a result, the immune system reacts by making a type of antibody called IgE to defend against the allergen. This reaction leads to allergy symptoms.

Information

Common allergens include:

  • Animal proteins and animal dander
  • Dust
  • Drugs (such as antibiotics or medicines you put on your skin)
  • Foods (such as egg, peanut, milk, nuts, soy, fish, animal meat, and wheat)
  • Fungal spores
  • Insect and mite feces
  • Insect bites and stings (their venom)
  • Natural rubber latex
  • Pollen

References

Stewart GA, Richardson JP, Zhang J, Robinson C. The structure and function of allergens. In: Adkinson NF, Bochner BS, Burks AW, et al, eds. Middleton's Allergy Principles and Practice. 8th ed. Philadelphia, PA: Elsevier Saunders; 2014:chap 26.

    • Positive reaction to allergen

      Positive reaction to allergen - illustration

      Allergic reaction is a sensitivity to a specific substance, called an allergen, that is contacted through the skin, inhaled into the lungs, swallowed or injected. The body's reaction to an allergen can be mild, such as a localized rash, or life-threatening, such as anaphylactic shock.

      Positive reaction to allergen

      illustration

      • Positive reaction to allergen

        Positive reaction to allergen - illustration

        Allergic reaction is a sensitivity to a specific substance, called an allergen, that is contacted through the skin, inhaled into the lungs, swallowed or injected. The body's reaction to an allergen can be mild, such as a localized rash, or life-threatening, such as anaphylactic shock.

        Positive reaction to allergen

        illustration

      Review Date: 1/26/2017

      Reviewed By: Linda J. Vorvick, MD, Clinical Associate Professor, Department of Family Medicine, UW Medicine, School of Medicine, University of Washington, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

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