Frequency of selective immediate responders to aminopenicillins and cephalosporins in Turkish children.

BACKGROUND: Beta-lactam antibiotics (BLA) are the most commonly prescribed antibiotics and are responsible for the majority of immediate hypersensitivity reactions to drugs in children. Cross-reactivity is important in hypersensitivity to BLAs because these drugs all share a common beta-lactam structure and some share similar side chains.

OBJECTIVE: The aim of this study was to evaluate the clinical characteristics of patients who are diagnosed with immediate-type BLA hypersensitivity and frequency of patients with side chain hypersensitivity, "selective responders."

METHODS: The study included patients who were diagnosed with immediate-type BLA hypersensitivity between January 2011 and May 2016 in a pediatric allergy outpatient clinic. The patients who had negative penicillin test (minor determinant mixture, benzylpenicilloylpoly-L-lysine, penicillin G) results and could tolerate penicillin V and/or BLAs with dissimilar side chains but had positive skin and/or provocation test results with the suspected drug were diagnosed as selective responders.

RESULTS: During the study period, 357 patients (55.2% girls) were admitted to our clinic with suspected immediate-type BLA hypersensitivity. Parents of 11 patients did not give consent for an allergy workup with the suspected drug. Forty-five of the patients were diagnosed (45/346 [13%]) based on skin test or drug provocation test results. The most common susceptible agent was amoxicillin-clavulanate. Of the patients, 71.4% with a reaction to sulbactam-ampicillin /or amoxicillin-clavulanate and 93.7% with a reaction to cephalosporin were classified as selective responders.

CONCLUSION: Among children with immediate BLA hypersensitivity, selective responders constituted an important group. Most of the patients with reactions to aminopenicillin and cephalosporins safely tolerated penicillin V and BLAs with dissimilar side chains after negative allergy workup results.