An allergy starts when your immune system mistakes a normally harmless substance for a dangerous invader. The immune system then produces antibodies that remain on the alert for that particular allergen. When you're exposed to the allergen again, these antibodies can release a number of immune system chemicals, such as histamine, that cause allergy symptoms.

Common allergy triggers include:

  • Airborne allergens, such as pollen, animal dander, dust mites and mold
  • Certain foods, particularly peanuts, tree nuts, wheat, soy, fish, shellfish, eggs and milk
  • Insect stings, such as bee stings or wasp stings
  • Medications, particularly penicillin or penicillin-based antibiotics
  • Latex or other substances you touch, which can cause allergic skin reactions
Aug. 14, 2014

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