Immediate reaction to roxithromycin and prick test cross-sensitization to erythromycin and clarithromycin.

Allergic reactions to macrolides appear to be very rare. Only a few cases of fixed drug eruption or urticaria due to the administration of erythromycin have been reported. Cross-reaction between the different macrolides have not yet been published. We report a case of a 31-year-old female patient who developed generalized urticaria and tachycardia shortly after administration of roxithromycin (Rulid). Immediate-type hypersensitivity was confirmed by positive prick test reactions to roxithromycin and the chemically closely related macrolides erythromycin and clarithromycin.