CausesBy Mayo Clinic staff
Peanut allergy occurs when your immune system mistakenly identifies peanut proteins as something harmful. When you have direct or indirect contact with peanuts, your immune system releases symptom-causing chemicals into your bloodstream. It isn't known exactly why some people become allergic to peanuts and others don't.
Exposure to peanuts can occur in different ways:
- Direct contact. The most common cause of peanut allergy is eating peanuts or peanut-containing foods. Sometimes direct skin contact with peanuts can trigger an allergic reaction.
- Cross-contact. This is the unintended introduction of peanuts into a product. It's generally the result of a food being exposed to peanuts during processing or handling.
- Inhalation. An allergic reaction may occur if you inhale dust or aerosols containing peanuts, such as that of peanut flour or peanut oil cooking spray.
Food allergy vs. food intolerance
In some cases, what may appear to be a food allergy may actually be a food intolerance. Unlike a true food allergy, a food intolerance doesn't involve the immune system. With a true food allergy, even tiny amounts of the food can cause a severe reaction. In most cases, someone who has a food intolerance can eat small amounts of the food with only mild symptoms, such as indigestion or heartburn.
- Peanuts. Food Allergy and Anaphylaxis Network. http://www.foodallergy.org/page/peanuts. Accessed March 4, 2012.
- Food allergy: An overview. National Institute of Allergy and Infectious Diseases. http://www.niaid.nih.gov/topics/foodAllergy/research/Pages/ReportFoodAllergy.aspx. Accessed March 4, 2012.
- Husain Z, et al. Peanut allergy: An increasingly common life-threatening disorder. Journal of the American Academy of Dermatology. 2012;66:136.
- Finkelman FD. Peanut allergy and anaphylaxis. Current Opinion in Immunology. 2010;22:783.
- Tintinalli JE, et al. Tintinalli's Emergency Medicine: A Comprehensive Study Guide. 7th ed. New York, N.Y.: The McGraw-Hill Companies; 2011. http://www.accessmedicine.com/content.aspx?aID=6358201. Accessed March 4, 2012.
- Hay WW, et al. Current Diagnosis & Treatment: Pediatrics. 20th ed. New York, N.Y.: The McGraw-Hill Companies; 2011. http://www.accessmedicine.com/content.aspx?aID=6589316. Accessed March 4, 2012.
- Pansare M, et al. Peanut allergy. Current Opinion in Pediatrics. 2010;22:642.
- Guidelines for the diagnosis and management of food allergy in the United States: Summary of the NIAID-sponsored expert panel report. National Institute of Allergy and Infectious Diseases. http://www.niaid.nih.gov/topics/foodAllergy/clinical/Pages/default.aspx. Accessed March 6, 2012.
- School guidelines for managing students with food allergies. The Food Allergy & Anaphylaxis Network. http://www.foodallergy.org/page/food-allergy--anaphylaxis-network-guidelines. Accessed March 6, 2012.
- Peanut allergy. American College of Allergy, Asthma and Immunology. http://www.acaai.org/allergist/allergies/Types/food-allergies/types/Pages/peanut-allergy.aspx. Accessed March 6, 2012.
- Kim EH, et al. Sublingual immunotherapy for peanut allergy: Clinical and immunologic evidence of desensitization. Journal of Allergy and Clinical Immunology. 2011;127:640.
- Stahl MC, et al. Potential therapies for peanut allergy. Annals of Allergy, Asthma & Immunology. 2011;106:179.
- Varshney P, et al. A randomized controlled study of peanut oral immunotherapy: Clinical desensitization and modulation of the allergic response. Journal of Allergy and Clinical Immunology. 2011;127:654.