Is penicillin allergy delabeling in primary care safe?

Published online: June 18, 2024

Up to 10% of the population have a penicillin allergy label. However, after evaluation, more than 90% of these patients can tolerate penicillin and can be delabeled (the label is removed from the medical record). Inappropriate allergy labeling has a significant impact on antimicrobial resistance and healthcare expenditures, and it can cause more adverse drug reactions. To optimize resources and diagnostic performance of allergy tests, in patients at low risk of ‘true’ penicillin allergy, delabeling can be achieved by administering the offending drug in a controlled setting (i.e. direct drug challenge (dDC)) without prior skin and/or in vitro tests. Currently, delabeling with dDC is almost exclusively performed by allergy specialists. Given the epidemiological data on spurious penicillin allergy, it would be worthwhile for low-risk patients to be delabeled, by mean of a dDC, also in resource-limited settings such as primary care.

In a recent publication in The Journal of Allergy and Clinical Immunology: In Practice, the safety of delabeling adults at low risk for having penicillin allergy in primary care was examined. Stul and colleagues systematically reviewed the current literature to perform a meta-analysis of studies in which patients with a penicillin allergy label were tested with a dDC in primary care or similar settings.

1070 participants in 12 studies were investigated for removal of the penicillin allergy label. In 97% of patients previously labeled as penicillin allergic, no reactions occurred, and the label was safely removed. Only 10 patients (<1%) had an immediate reaction during the dDC and 20 patients (<2%) had a delayed reaction in the days following the challenge. No serious allergic reactions or critical events were observed during the challenges performed in primary care or outpatient settings. This review concludes that there are similar safety results compared with dDC in low-risk adults in a hospital setting. Therefore, delabeling low-risk patients in primary care using a dDC could be safe, provided the primary care team is adequately trained to identify low-risk patients and to interpret and manage reactions to a challenge. Further research is required to correctly classify patients as low-risk and to assess safety in large cohort studies evaluating direct drug challenges in primary care.

The Journal of Allergy and Clinical Immunology: In Practice is an official journal of the AAAAI, focusing on practical information for the practicing clinician.

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