Beta lactam allergies in a large obstetric population: developing an allergy testing referral system

Abstract

Beta lactam antibiotics are frequently indicated in obstetric care. We aim to describe beta lactam allergies in our obstetric population, improve identification and documentation of IgE-mediated allergies, and develop an expedited referral pathway for allergy relabeling. A retrospective chart review of beta lactam allergies in our patients who delivered within 2019-2020 was performed. A prospective referral system for allergy testing was then implemented from January-June 2022. Patients with previously documented allergies were flagged in the electronic medical record (EMR). Provider and patient education were provided to guide referrals. Allergy testing included skin testing and a graded amoxicillin challenge. Of the 7788 patients who delivered within 2019-2020, 365 (4.7%) reported beta lactam allergies. Penicillin (233, 63.8%) and amoxicillin (82, 22.5%) were the most common (Table 1). Of the patients with group B streptococcus colonization, 64/79 (81.0%) received an antibiotic other than penicillin. Forty-six patients received an antibiotic other than cefazolin (46/115, 40%) for cesarean perioperative prophylaxis. Chorioamnionitis was treated in 24 patients, and 21/24 (87.5%) received a regimen other than ampicillin/gentamicin. Since January 2022, 72 patients with reported beta lactam allergies were identified in one obstetric clinic (Figure 2). Of those, 54 (75%) were appropriately screened by their primary provider. Nine patients (9/54, 16.7%) were not referred due to recent anaphylaxis or lack of a IgE allergy. Nineteen patients (26.4%) have completed allergy testing thus far: 18/19 patients (94.7%) patients tolerated testing without allergic reaction and their beta lactam allergy was removed from the EMR. Beta lactam allergies are commonly reported by obstetric patients, which contributes to alternative antibiotic use. Patients can benefit from an expedited referral process for allergy testing to improve antibiotic stewardship in obstetrics. We have demonstrated the implementation of a successful multidisciplinary referral system for this testing.View Large Image Figure ViewerDownload Hi-res image Download (PPT)