001757 - Suspected Beta-Lactam Allergy in Young Children: A Delabeling Approach

Suspected beta-lactam hypersensitivity, particularly to penicillin and amoxicillin, represents the leading cause of referral to pediatric allergy units. The self-reported prevalence of beta-lactam allergy in children ranges from 1.7% to 5.2%; however, fewer than 20% of cases are confirmed as true allergies after allergological evaluation. Anaphylaxis is uncommon (0.01%–0.05%) and generally presents with milder clinical features in pediatric populations. The aim of this study was to analyze the clinical characteristics and outcomes of pediatric patients referred to our center with suspected beta-lactam allergy over a five-year period.

We performed a retrospective study including children younger than 6 years referred for suspected beta-lactam hypersensitivity between 2020 and 2024 (n = 256). Collected data included sex, age at reaction, presence of concomitant allergic diseases, suspected antibiotic, reaction phenotype and severity, diagnostic procedures, and tolerance following oral drug provocation testing.

The majority of patients were male (54.7%), with the most frequent age group being 2–3 years (23.4%). At the time of the index reaction, 34% of patients had an underlying allergic condition. Amoxicillin was the most frequently suspected antibiotic (65%), followed by amoxicillin–clavulanic acid (34%) and cefixime (1%). Cutaneous manifestations were observed in 96% of reactions; 87% were delayed in onset and 98% were classified as mild. Drug provocation testing was performed in 92% of cases, with the implicated antibiotic used in all but one patient, with positive results in 8%. Among patients with confirmed hypersensitivity, beta-lactam antibiotics were withdrawn in only 10% (n = 3). Figure 1 summarizes the diagnostic workflow and outcomes of drug provocation testing.

In this pediatric cohort, suspected beta-lactam hypersensitivity was mainly characterized by mild, delayed cutaneous reactions, with a low rate of confirmed allergy following diagnostic evaluation. Oral drug provocation testing proved to be a safe and effective diagnostic tool, enabling delabeling and confirmation of beta-lactam tolerance in the majority of patients. These findings underscore the importance of systematic allergological assessment to prevent inappropriate beta-lactam avoidance and optimize antibiotic use in young children.