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Definition
By Mayo Clinic staffAllergies occur when your immune system reacts to a foreign substance such as pollen, bee venom or pet dander.
The immune system produces proteins known as IgE antibodies. These antibodies protect you from unwanted invaders that could make you sick or cause an infection. When you have allergies, your immune system makes antibodies that identify your particular allergen as something harmful, even though it isn't. This triggers the release of histamines and other substances that cause allergy symptoms.
Allergies can cause symptoms that involve your skin, sinuses, airways or digestive system. The severity of allergies varies from person to person and can range from minor irritation to anaphylaxis — a potentially life-threatening emergency. While allergies can't be cured, a number of treatments can help relieve your allergy symptoms.
Symptoms- Allergy. National Institute of Allergy and Infectious Diseases. http://www.nlm.nih.gov/medlineplus/allergy. Accessed Jan. 7, 2009.
- Frequently Asked Questions (FAQ). American College of Allergy, Asthma & Immunology. http://www.acaai.org/public/questions/frequent.htm. Accessed Jan. 7, 2009.
- Tips to Remember: What is an allergic reaction? American Academy of Allergy, Asthma & Immunology. http://www.aaaai.org/patients/publicedmat/tips/whatisallergicreaction.stm. Accessed Jan. 7, 2009.
- Bauer BA. Mayo Clinic Book of Alternative Medicine. New York, N.Y.: Time Inc.; 2007:156-157.
