Epidemiology and drug allergy results in children investigated in allergy unit of a tertiary-care paediatric hospital setting

Background and objective Drug Hypersensitivity Reactions (DHRs) are considered adverse effects of medications that resemble allergy symptoms. The reported positive clinical history of pediatric drug reactions is about 10%, however, after allergy investigations, only a small percent is confirmed as hypersensitivity. The aim of this study was to analyze the clinical history, allergy work-up results and sensitization profile of children and adolescents referred to our Allergy Unit for suspected DHRs. Methods The study evaluated data related to a group of children with a positive history of drug reactions during a two-year period. The allergy work-up consisted of in vivo and in vitro tests, in accordance with the recommendations of the ENDA/EAACI guidelines. Results Data from a group of 637 patients [348 M (54.6%); 289 F (45.4%)] were retrospectively analyzed. Beta lactams (BLs) were the most common drugs involved in the reported clinical history, followed by non-steroidal anti-inflammatory drugs (NSAIDs). Severe cutaneous adverse reactions (SCARs) were most frequently observed during BL treatment. The confirmation of BL hypersensitivity was higher for immediate reactions (IRs) [9.4%; 5.1% through positive skin tests (STs) and 5.5% through drug provocation test (DPT)] compared to non-immediate reactions (non-IRs) (8.1%; 2.2% through STs and 6.2% through DPT). A higher number of positive results was obtained for BLs and macrolides when the tests were performed within 12 months after the index reaction (p < 0.05). During DPTs with amoxicillin-clavulanic acid, four hypersensitivity reactions (including one anaphylaxis) occurred despite negative STs. Conclusion Our data demonstrated that only 9.1% of patients resulted in being positive to allergy tests which is in line with the data in literature. An allergy work-up is mandatory for excluding suspected hypersensitivity.