Characterization of Amoxicillin‐Associated Reactions Presenting to the Emergency Department: 90

Abstract

Katharine M. Amalfitano, MD, Susan S. Xie, MD, Joshua D. Courter, PharmD, Chunyan Liu, MS, and Kimberly A. Risma, MD, PhD, FAAAAI; Cincinnati Children’s Hospital Medical Center, Cincinnati, OH. RATIONALE: Recent studies published by allergists demonstrate most children with amoxicillin-associated reactions (AAR) are non-allergic when rechallenged, irrespective of initial presentation of urticaria, maculopapular exanthem (MPE), or serum sickness-like reaction (SSLR). If generalizable to all children with AAR, these studies have significant impact. Surprisingly, no studies have been published which carefully phenotype children presenting with AAR in primary care settings, such as the emergency department (ED). METHODS: Retrospective chart review was conducted on Cincinnati Children’s ED encounters July 1, 2015-June 30, 2017 using 11 relevant ICD-10 billing codes. Patients with AAR, age <19 years, were extracted and 3 clinical phenotypes (urticaria, MPE, and SSLR) identified based upon detailed provider description. RESULTS: Of the 668 children with AAR, 290 (43%) presented with urticaria, 242 (36%) with MPE, and 71 (11%) with SSLR. Median (25, 75 percentiles) age at presentation was earliest for MPE (1.45yrs (0.9,4.3)), followed by urticaria (1.8yrs (1.1,5.2)), then SSLR (2.5yrs (1.6,5.0)) (p50.01). Day of onset post-antibiotic initiation was bimodal for MPE; whereas urticaria and SSLR had unimodal peaks at days 7 and 8 respectively (p<0.0001). Patients with SSLR had higher rates of associated angioedema and fever and more frequently received oral steroids and returned to the ED (p<0.0001). CONCLUSIONS: We characterized for the first time a pediatric cohort of ED patients with AAR notable for their young age and at least 3 distinct clinical phenotypes. Prospective studies are needed to determine the rate of tolerance with amoxicillin re-exposure following EDAAR, particularly in patients with SSLR, which were more common than expected.