Anaphylaxis: Symptoms & Signs

Anaphylaxis is a rare, severe allergic reaction that is life-threatening. The most common allergic triggers of anaphylaxis include drugs (such as penicillin), insect stings, foods (peanuts, shellfish), X-ray dye, and latex. Symptoms and signs can vary and begin either immediately after contact with the allergen or after a short time period (15 minutes to an hour). Hives, difficulty breathing, a feeling of impending doom, and reduced blood pressure are among the symptoms and signs that can occur. The severity of symptoms and signs varies among people; the more rapid the onset of symptoms and signs, the greater the likelihood of a severe reaction.


Kasper, D.L., et al., eds. Harrison's Principles of Internal Medicine, 19th Ed. United States: McGraw-Hill Education, 2015.

Medically Reviewed by a Doctor on 9/15/2015

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