Boosted IgE response after anaphylaxis reaction to cefuroxime with cross-reactivity with cefotaxime

Background: Cefuroxime is a second-generation lactamase-stable cephalosporin. Its use is on the increase, and in recent years several reactions to this compound have been reported. Objective: To describe a case of selective reaction to cefuroxime, showing a boosted immunoglobulin (Ig)E response after administration of this drug. Methods: Specific serum IgE antibodies to several cephalosporins were monitored in a 52-year-old man after a selective systemic anaphylaxis attributable to cefuroxime, who showed a good tolerance to penicillin V during a single-blind, placebo-controlled challenge. Results: Specific IgE levels to cefuroxime were not detected at the moment of the reaction but became positive 1 day after, increasing to peak at day 51, and still positive after 115 days. Through radioallergosorbent test inhibition, cross-reactivity between cefuroxime and cefotaxime was demonstrated. Conclusions: IgE-mediated reaction attributable to cefuroxime with cross-reactivity to cefotaxime was reported. A prompt evaluation undertaking skin tests and additional radioallergosorbent test studies with different betalactam derivatives improves the evaluation of subjects with allergic reactions to betalactams.