Negative penicillin allergy test? Check. Updated electronic medical record (EMR) to de-label the allergy? Check. Access to penicillin? Denied. This is a common scenario among patients whose pharmacies have not successfully de-labeled the patient’s penicillin allergy, according to findings presented at the 2023 Annual Meeting of the American Academy of Allergy, Asthma & Immunology (AAAAI) held February 24 to 27 in San Antonio, Texas.

The findings illustrate the obstacles that remain in de-labeling penicillin allergies. The study found that patients bear the burden of higher costs and risks associated with starting on broad-spectrum antibiotics when EMRs and pharmacy records are not updated to de-label penicillin allergies.

“Penicillin allergy labels are associated with increased health care cost burdens as well as adverse events for patients,” said Althea Marie Diaz, MD, primary author of the study. “Many patients carrying a penicillin allergy label can safely take penicillin, but even after allergy testing we’re finding those allergy labels aren’t always being removed.”

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The researchers studied 78 patients who had penicillin allergies de-labeled based on negative skin testing and aminopenicillin oral challenge between May 2019 and May 2022 at a single site. To streamline communication regarding the de-labeling between the patient and their health care team, researchers sent a letter to the patient’s primary care physician and pharmacy of choice and followed up with phone interviews with both the patients and pharmacies.

Pharmacies successfully de-labeled patients’ penicillin allergy in 31% of cases, despite clinicians updating the EMR to de-label the allergy in 99% of cases.

“We’ve come a long way when it comes to de-labeling penicillin allergies, but we have a long way to go,” said Dr Diaz, an allergist-immunologist at NYU Langone Long Island Hospital. “We need to continue to examine what barriers are preventing us from completely de-labeling patients who can safely take penicillin and develop strategies to address those barriers.”

Most of the patients (n=68) participated in follow-up interviews. Among this population, 52% had not taken penicillin since their allergy was de-labeled and 6% were intentionally avoiding taking penicillin despite having a negative allergy test. Just under half (44%) of these patients had taken penicillin since the de-labeling, and 4% had unknown antibiotic use.

The EMR de-labeling was effective in helping patients recall that they have a negative penicillin allergy result; 97% of the patients who were interviewed recalled testing negative for a penicillin allergy. However, until patients’ penicillin allergy is fully de-labeled pharmacy records, they will continue to shoulder the burdens associated with not being able to safely take penicillin.


Diaz AM, Fonacier L, Stern H, Mawhirt S, Banta E, Sani S. Persistent penicillin allergy label in pharmacies after penicillin allergy de-labeling. J Allergy Clin Immunol. 2023;151(2 suppl):AB112. doi:

Following patient penicillin allergy de-labeling, pharmacy records aren’t always updated to reflect changes. News release. American Academy of Allergy Asthma & Immunology. February 3, 2023. Accessed February 28, 2023.