Late reaction to oral nystatin: the importance of patch testing.

A 63-year-old man with lung carcinoma and no history of contact dermatitis presented an intense erythematopapular eruption on his arms, back, and groin after a 3-day course of corticosteroids following chemotherapy. He had tolerated an initial chemotherapy cycle with paclitaxel and cisplatin well. The patient had received the following drugs: cisplatin, paclitaxel, granisetron, bemiparin, osmofundin, metoclopramide and was still under treatment with levothyroxine and nystatin (Mycostatin oral suspension). Nystatin was stopped and the lesions resolved within 7 days. Patch tests performed with the European standard series of allergens and cisplatin, paclitaxel, granisetron, bemiparin, osmofundin, metoclopramide and Mycostatin oral suspension were positive only to balsam of Peru (+) at 48 and 96 hours. Interestingly, the patient tolerated the subsequent chemotherapy cycles with the same drugs except nystatin well.