Penicillin Allergy Testing Aids in Antibiotic Stewardship

A new study conducted by the University of Maryland has shown that most people who think that they have a penicillin allergy, do not. With more access to testing for penicillin allergy within the hospital setting, and through the use of an infectious disease (ID) fellow-managed penicillin skin testing (PST) program, consisting of physicians, antibiotic use within hospitals can improve, according to the press release.

Through an observational study, the researchers aimed to test how feasible it would be to have a penicillin allergy skin testing service managed by ID physicians. These physicians were educated and trained in regards to penicillin allergy testing and then selected the patients that would be tested for the allergy.

The study’s findings have found that with penicillin allergy testing, there are opportunities for improvement. According to the press release, “[A total of] 84% of those who tested negative for penicillin allergy were given antibiotic changes, 63% received a narrower spectrum antibiotic, 80% received a more effective therapy, and 61% received more cost effective therapy.”

Emily L. Heil, PharmD, BCPS-AQ ID, lead author of the study and an assistant professor of pharmacy practice and science at the University of Maryland School of Pharmacy, said, “Our study found that many people who think they have a penicillin allergy actually do not when penicillin allergy skin testing is performed, which mirrors results of several other studies in the literature that demonstrate that up to approximately 9 out of 10 people who think they have a penicillin allergy do not, when tested. Clearing patient’s allergy records of a penicillin allergy has been tremendously helpful to our antimicrobial stewardship program and has allowed us to transition these patients to more cost-effective, clinically-effective and narrower spectrum antibiotics.”

A total of 76 patients at the University of Maryland Medical Center who said that they had a penicillin allergy were tested. According to the study, 96% of these patients were not actually allergic.

This year, the Centers for Disease Control and Prevention (CDC) has addressed the need to implement interventions in healthcare settings due to the fact that several national studies have shown similar results. In “The National Quality Partners Playbook: Antibiotic Stewardship in Acute Care,” they specifically mention the need to “establish guidance for antibiotic allergy assessment,” listing penicillin allergy assessment protocol under system-wide interventions with the aim to improve treatment when it comes to antibiotics.

Additionally, researchers found that the ID fellow-managed PST program was not only effective, but it also proved that allergists, who typically work in outpatient settings, are not the only ones who can find out if patients are allergic to penicillin; ID fellows can be trained. Dr. Heil said, “These outcomes can be attributed to infectious disease fellows performing the testing as we have no allergists consulting on adult cases in our inpatient facility. The ID fellows allowed our patients to have access to this important testing.”

The University of Maryland led a national survey of ID specialists that showed that the main barriers when it comes to testing for penicillin allergy are: not enough personnel available to administer the tests and a lack to time to perform them, according to the press release. The survey also made note of the fact that since most people who think they are allergic to penicillin do not actually have the allergy, choice of antibiotics is impacted. Dr. Heil stated that teaching the ID fellows to perform these tests can reduce cost as well as improve the patient’s quality of care that they receive in the hospital.