The Diagnosis of Ceftriaxone Hypersensitivity in a Paediatric Population

INTRODUCTION: Penicillins and cephalosporins are the most frequent causes of hypersensitivity reactions (HRs) to drugs in children. Among cephalosporins for intravenous use, ceftriaxone (CT) is the most frequently prescribed in Italy. The aims of this study were to evaluate the diagnostic methods for CT hypersensitivity in a population of children with suspected HRs to this drug and their tolerance toward amoxi-cillin/clavulanic acid (AMX/CLV). MATERIALS AND METHODS: From 2012 to 2018, 90 children were investigated for suspected HRs to CT according to the European Academy of Allergy Asthma and Clinical Immunology (EAACI) guidelines. RESULTS: Ninety children had a history of reaction to CT. The majority (79/90; 77.8%) had a history of immediate reactions (IRs). CT hypersensitivity was confirmed in 26/90 patients (28.9%). In case of IRs, skin tests can be useful (24% of positive CT intradermal tests - IDTs) particularly in cases of anaphylaxis (81.8% of positive CT IDTs). Only 5 out of 28 drug provocation tests were positive. Serum-specific IgE (sIgE) determination for CT correlated with positivity upon skin/drug provocation tests (high specificity 95.6%) but had a low sensitivity; sIgE for AMX had a very low positive predictive value (14.3%), advocating against its use. In case of non-IRs, only 7/11 patients reached a confident diagnosis, but the low number of children does not enable proper conclusions. Only 2 children showed cross- and/or co-allergy (2.2%) between CT and AMX/CLV. CONCLUSION: IDTs seem to be useful for diagnosing CT IRs. Hypersensitivity to CT is confirmed in 28.9% of children, although a large fraction of parents refused an intravenous rechallenge (45.6%). It remains unknown whether this is due to the fact this was intravenous rather than a rechallenge with the culprit, but it reflects a clinical reality. Otherwise, cross- and/or co-allergy between CT and AMX/CLV is a rare event.