Hypersensitivity to beta-lactam antibiotics: a three-year study

Beta-lactams antibiotics (BL) are the most frequent elicitors of allergic drug reactions. The aim of our study was to characterize the patients referred with suspected hypersensitivity (HS) to BL.

Over a three-year period (2011-2013), a total of 234 adult and paediatric patients (pts) with suspected HS to BL were investigated according to the European Network for Drug Allergy guidelines.

HS to BL was confirmed in 43 pts (18%), without differences between adult and paediatric pts; anaphylaxis was reported by 20 pts. Diagnosis was ascertained by: serum-specific IgE antibodies in 5 pts (12%), skin prick tests in 5 (12%), intradermal tests in 25 (58%), 3 with delayed reading, and the remaining 8 (18%) by drug provocation tests. Penicillins / derivatives were the culprit drugs in 39 pts, mainly amoxicillin, and cephalosporins in 4.

In most of these patients with suspected HS to BL, allergological work-up was negative and HS was excluded. One fourth of confirmed cases had a plausible non-IgE mediated mechanism.