[Eosinophilic cystitis induced by tranilast: a case report].

We report a patient with tranilast-induced eosinophilic cystitis who had no allergies, but had been administered tranilast to reduce prednisolone. A 62-year-old man presented with macroscopic hematuria and bladder irritative symptoms. The patient had a past medical history of idiopathic thrombocytopenic purpula and had been treated with 15 mg of prednisolone since 1980. He had been receiving 300 mg of tranilast for the past 18 months. Urinalysis revealed a marked increase in eosinophils (4 x 10(4)/ml). A cystoscopic examination revealed reddish mucosa throughout the bladder. A retrograde cystogram showed incomplete bilateral vesicoureteral reflux. Histological examinations of biopsied bladder specimens revealed a marked increase in the number of eosinophils (1,126/mm2), but not of mast cells (12/mm2). The symptoms resolved within one week after cessation of tranilast.