To comprehensively delineate the entire range of symptoms linked with amoxicillin-associated reactions (AARs) in pediatric patients in the emergency department (ED) and urgent care facility (UC).

This retrospective analysis of medical records for pediatric patients seen in the ED/UC between July 1, 2015, and June 30, 2017, meticulously documented clinical manifestations, timing of symptoms, and seasonal patterns. These cases were categorized into 3 regular presentations of AAR: urticaria, maculopapular exanthem (MPE) and serum sickness-like reactions (SSLRs) characterized by the presence of joint symptoms.

A total of 668 children, with a median age of 1.8 years, sought care in the ED/UC for urticaria (44%), MPE (36%), and SSLRs (11%), usually happening between days 7 to 10 following the exposure to Amoxicillin.

Children experiencing SSLRs were more commonly administered corticosteroids (28%, P < .0001) and displayed higher rates of "worrisome" features, such as angioedema, fever or gastrointestinal symptoms (73%). Surprisingly, a significant proportion of children (10%) returned to the ED/UC for re-examination.

The presence of "worrisome" symptoms is prevalent among children presenting to the ED/UC with allergies or reactions to Amoxicillin. Further investigations are necessary to evaluate the implications of these findings on subsequent referrals and allergy testing.