Antibiotic allergy labels in children attending a tertiary paediatric allergy clinic

Background: Antibiotic allergy labels are common in children, although many are assigned on the basis of clinical history and are not confirmed following specialist evaluation. Objective: To determine the prevalence of suspected antibiotic allergy labels and to describe implicated antibiotics, reaction phenotypes, temporal trends, atopic comorbidities and oral drug provocation (ODP) outcomes among children attending a tertiary paediatric allergy clinic. Methods: We performed a retrospective observational study of children aged 0–17 years attending a tertiary paediatric allergy outpatient clinic in Athens, Greece, between January 2023 and December 2025. Data on reported antibiotic allergy, implicated agents, reaction phenotypes, atopic comorbidities and ODP outcomes were extracted from specialist clinical records. Results: Among 742 outpatient visits representing 569 unique children, 57 visits (7.7%; 95% CI 6.0–9.8) and 55 children (9.7%) carried a suspected antibiotic allergy label. Label prevalence declined from 10.7% in 2023 to 4.7% in 2025. Aminopenicillins accounted for 77.4% of implicated antibiotic entries, with amoxicillin-clavulanate being the most frequently implicated agent. Delayed cutaneous reactions predominated (81.0%), whereas immediate reactions were uncommon (10.3%). Among 56 completed ODP assessments, 52 (92.9%) demonstrated tolerance, including 44/47 delayed cutaneous reactions, 5/6 immediate reactions and all three challenged serum sickness-like reactions. Conclusion: In this tertiary pediatric allergy cohort, reported antibiotic allergy predominantly reflected histories of non-severe beta-lactam reactions and was infrequently confirmed following specialist evaluation. These findings support careful clinical assessment and structured risk stratification, with ODP performed by experienced specialists in appropriately selected children as part of antibiotic allergy delabelling pathways.