Does you or your child have a penicillin allergy? You're not alone. Many people are unsure, and a past rash can lead to a broad "penicillin allergy" label, which limits treatment options for future infections. People often outgrow penicillin allergies, and accurate testing can open the door to safer, more effective antibiotics. This section provides you with information about the risks of misdiagnosis and the benefits of penicillin allergy testing.