What is The Utility of Penicillin Skin Testing for Patients Labeled as Penicillin Allergic?

Meghan Jeffres, PharmD, assistant professor in the Department of Clinical Pharmacy, University of Colorado Skaggs School of Pharmacy, discusses the utility of penicillin skin testing for patients labeled as penicillin allergic.

Interview Transcript (slightly modified for readability):

“Recently, penicillin skin testing has become a means to identify patients that are not truly allergic to penicillin, in an effort to decrease anxiety about using beta-lactams in this group. Penicillin skin testing does a great job of identifying patients that either are, or are not going to have Immunoglobulin E (IgE)-mediated or anaphylactoid-like reactions. [Penicillin skin testing] does not do anything to identify any other types of allergic reactions. There is a subset of patients that are allergic to penicillin that will have anaphylactoid-like reactions; a penicillin skin test will identify those types of patients and then you know to not use penicillin or its cross-reactive reagents in this patient.

What you do not find out is if this patient, 5 days from now, is going to have a rash, or is going to develop nephrotoxicity or hepatotoxicity from an allergic reaction.

[Penicillin skin testing] has a role, but I think it’s a potentially smaller role. The studies that have been looking at the utility of penicillin skin testing have shown that it increases beta-lactam use once patients have been tested, but I would argue that it is probably not even necessary to do the test, and in fact, you can just use a beta-lactam in these patients that have a low risk of having an anaphylactoid-like reaction.”