More evidence supports that proceeding directly to an oral penicillin challenge in patients who are low risk for penicillin allergy. This review highlights two studies using allergy history-taking to determine eligibility for direct oral penicillin challenge.

In the PALACE randomized clinical trial, investigators selected participants reporting low-risk penicillin allergies via PEN-FAST tool in this multicenter, non-inferiority, randomized clinical trial to undergo direct oral challenge (intervention) or skin-testing followed by oral challenge if the skin test is negative (control; standard-of-care). PEN-FAST is a short questionnaire validated to assess risk for penicillin allergy in patients reporting such an allergy; those deemed “low” and “very low” risk of a positive allergy test were eligible. A total of 382 outpatient adults across 6 medical centers in Australia, US and Canada were randomized. One patient in each group (0.5%) had a positive oral penicillin challenge (primary outcome); both were treated successfully with oral antihistamines. The trial met their non-inferiority margin of 5%. There was no difference in delayed immune reactions up to 5 days. These findings offer clinicians without the time or resources to implement penicillin skin testing as a safe alternative to skin-testing, which may be easily adaptable to inpatient settings.

In an observational, quasi-experimental study at a non-teaching community medical center in New Jersey, investigators created a medication allergy history interview questionnaire and a medication allergy assessment algorithm to classify patients as low vs moderate vs high risk of allergy. Low risk patients could undergo oral beta-lactam challenge, moderate risk patients were referred for skin testing, and high-risk patients continued avoidance. The objective of this intervention was to increase allergy history documentation in the electronic medical record and increase beta-lactam use. One-hundred eighty-four patients in the pre-intervention period was December 2018 to April 2019 were compared to 208 in the January-April 2021 post-intervention period. Using interrupted time-series analyses, they found that documentation of complete allergy histories increased by nearly 20%, and beta-lactam use increased by 9.3 days of therapy per 1000 days-present. This study emphasized that non-teaching, community hospitals can successfully implement beta-lactam allergy interventions and inspired greater confidence among their clinicians in proceeding to direct oral challenge in low-risk individuals.

Reference: 

Copaescu AM, Vogrin S, James F, et al. Efficacy of a Clinical Decision Rule to Enable Direct Oral Challenge in Patients With Low-Risk Penicillin Allergy: The PALACE Randomized Clinical Trial. JAMA Intern Med. 2023;183(9):944–952. doi:10.1001/jamainternmed.2023.2986

Trubiano JA, Vogrin S, Chua KYL, et al. Development and Validation of a Penicillin Allergy Clinical Decision Rule. JAMA Intern Med. 2020;180(5):745–752. doi:10.1001/jamainternmed.2020.0403

Vyas, L., Raja, K., Morrison, S., Beggs, D., Attalla, M., Patel, M., & Philips, M. (2023). Beta-lactam comprehensive allergy management program in a community medical center. Antimicrobial Stewardship & Healthcare Epidemiology, 3(1), E189. doi:10.1017/ash.2023.461

Article Submitted by Jenna Preusker, PharmD, Nebraska ASAP