Penicillin Allergy

This resource for Children’s Hospital of Philadelphia patients describes penicillin allergies.

Important information about penicillin:

Penicillins are a group of antibiotics that are commonly used to treat infections, including ear infections, sinus infections, strep throat, and respiratory infections. Examples of penicillins include penicillin, amoxicillin, and amoxicillin-clavulanate (Augmentin^®).

• They are often the most effective treatment for common bacterial infections.

• They are associated with fewer side effects and toxicities compared to other antibiotics.

• They are less likely to build antibiotic-resistance compared to other antibiotics by having a narrow spectrum of activity.

• They often cost less than other antibiotics.

• Alternative antibiotics are often associated with higher costs, increased risk of antibiotic-resistance, and suboptimal therapy.

What if my child is allergic to penicillin?

About 10% of people report a penicillin allergy. However, when evaluated, less than 1% are truly allergic to penicillins. About 80% of individuals with a true penicillin allergy lose their sensitivity after 10 years.

To determine whether or not your child has a true penicillin allergy, your healthcare provider may recommend that your child sees an allergist. This is a medical provider who specializes in allergies. The allergist will review your child’s history and recommend steps to check for a penicillin allergy. This can involve skin testing or an oral drug challenge.

If your child had a non-itchy rash toward the end of a course of a penicillin without any other symptoms, there is only a small chance that they have a true allergy. Your provider may choose to order penicillin again without seeing an allergist.

You should not be concerned about a penicillin allergy if:

• Your child has abdominal pain, diarrhea, or vomiting without any other symptoms.

• There is a family history of penicillin allergy, but your child has never taken penicillin.

• Your child had a possible reaction to a penicillin in the past but has received it afterward without reaction.

Contact your CHOP healthcare provider with questions or concerns.

Reviewed on November 2023, by Leah Rodriguez, PharmD, BCIDP