RESUMO
A fixed drug eruption (FDE) is a cutaneous reaction caused by various drugs. Mesna is used to decrease urotoxic side effect of cyclophosphamide and there have been no previously reported cases in Korea for any adverse reactions to this drug. Herein, we report a case of a FDE caused by mesna. A 34-year-old woman presented with asymptomatic, brownish macules and patches on the face and back for the past 4 months. She had been treated for SLE with monthly pulses of intravenous cyclophosphamide and mesna for 6 months. She had experienced similar episodes after injection of mesna. The skin biopsy specimen taken from her showed vacuolar degeneration of the basal cell layer and perivascular lymphohistiocyte infiltration in the papillary dermis. We performed prick test, scratch patch test, and intradermal test with mesna and confirmed that a FDE was caused by this drug.