Quick facts about penicillin allergy in the US

Up to 10% of patients in the US have been labelled as penicillin‐allergic

Up to 90% of patients reporting a penicillin allergy are not truly allergic to the medication

Up to 80% of patients who had a true allergy lose the sensitivity within 10 years

Why are so many people labelled as allergic to penicillin? Infections can cause a rash, particularly in children. If the rash doesn’t happen before taking antibiotics, it is often assumed that it was the antibiotic that caused the rash, not the infection. Since the penicillin family of antibiotics is commonly used in children, many people carry a lifelong diagnosis of the allergy after they had a rash during a respiratory infection early in life.

Avoiding penicillin has consequences

Penicillin and its related antibiotics are still considered an appropriate treatment for many common infections. If penicillin cannot be prescribed, broad‐spectrum antibiotics are used instead. These antibiotics are much more expensive, pose a risk of developing a drug‐resistant infection and can result in longer hospitalizations.

How does penicillin allergy testing work? Penicillin allergy testing is a three‐step process that can be done in a single office visit in less than a few hours. This must be done when you are feeling well, not as an infection is getting started.
1 ‐ Skin Prick Tests
2 ‐ Intradermal Tests
3 ‐ Oral Challenge
First, five penicillin allergens are placed on your skin and checked after 15 minutes. If these tests are negative, the allergens are next injected just under your skin, like a TB test. If both sets of tests are negative, we can safely do an oral challenge. In this final test, chewable tablets of penicillin antibiotics are given and we monitor you for one hour. If no reaction occurs, you can safely return home. In the case of an extremely mild allergy, a rash may appear in about 10 days. We’ll call you two weeks after your appointment to see if the rash appeared, and if it did not, you are not truly allergic to penicillin!

Have you been labelled as penicillin‐allergic? Call (414) 529‐8500 today!

Clearing your chart of a penicillin allergy diagnosis can save you money and keep you healthier. Call our office today to request a penicillin allergy testing appointment, or fill out the form below and we’ll contact you!

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Want to learn even more about penicillin allergy? Check out the following materials to learn more about the causes and effects of penicillin allergy, and how allergy skin testing is performed.
Facts for Patients
Why should I get tested?
Frequently Asked Questions
Allergy Skin Testing