Penicillin is one of the most commonly reported drug allergies. However, at least 80% of people who were penicillin allergic will no longer be allergic 10 years after the reaction. In fact, 95% of people labeled allergic turn out to have negative testing and can take penicillin again without problems. Simply avoiding penicillin anyway may sound simple, but there are risks:
- You may be prescribed other antibiotics which don’t work as well for the infection you have
- These other antibiotics tend to cause more adverse reactions, such as kidney injury, diarrhea, or further infections with drug-resistant bacteria
These problems are so serious and widespread that the Centers for Disease Control and Prevention (CDC) recommends a thorough evaluation of a suspected penicillin allergy before prescribing a broad-spectrum antibiotic.
Evaluation of a penicillin allergy first involves taking a history to find out when you had a reaction and what the symptoms were. Depending on your history, an allergist/immunologist may recommend further testing.
Skin testing for penicillin allergy is very helpful to detect a sensitization to penicillin. Based on the results, your provider may recommend a drug challenge. Once you pass a drug challenge, you are cleared of your penicillin allergy.