Penicillin allergy is an overreaction by your immune system to penicillin and related antibiotics. If you have a penicillin allergy, your reaction to taking the antibiotic may range from a rash to anaphylaxis, a potentially life-threatening condition.

Penicillin antibiotics are widely prescribed for bacterial infections, such as strep throat. However, not all unfavorable reactions to penicillin are a true penicillin allergy.

It isn't clear why some people develop penicillin allergy. Once you've had an allergic reaction to penicillin, the simplest way to prevent penicillin allergy is to avoid penicillin and related antibiotics.

Dec. 15, 2011

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