A Case of Bromoderma Caused by Long-term Use of a Commercial Antipyretic Analgesic Containing Bromovalerylurea

Abstract

A 50-year-old woman visited our department with a 1-month history of a painful nodule with ulcer formation on her left lower leg that arose after she scratched an insect bite wound. Her leg ulcer produced some exudates and the ulcer did not improve upon the application of Iodocoat^® ointment. Laboratory findings revealed hyperchloremia(156 mEq/l, normal range 98-108 mEq/l). Four years ago, she had treated chronic constipation with internal medicine and was found to have hyperchloremia, but closer inspection was not performed at that time. Through a detailed interview, we discovered that she had taken a commercial antipyretic analgesic(Naron^® Karyu) for 10 years. On this basis, we suspected that she had pseudohyperchloremia owing to an excessive intake of bromide. Histopathologically, we found hyperkeratosis and pseudocarcinomatous hyperplasia in the epidermis in addition to a thick infiltration of neutrophils and abscess formation in the dermis. Therefore, we diagnosed the case as bromoderma because of the clinical and histopathological findings, the prolonged administration of a bromide-containing drug, and an elevated blood bromide level(500 mg/l, less than 5 mg/l). After the discontinuation of oral bromide, her ulcer reepithelialized immediately and the hyperchloremia normalized. In conclusion, the assessment of a history of exposure to a bromide-containing drug and the detection of hyperchloremia are helpful for the diagnosis of bromoderma mimicking pyoderma gangrenosum.