LAUSR

INTRODUCTION Dapsone, or 4,49-diaminodiphenylsulfone, is commonly used in several dermatologic indications such as neutrophilic dermatoses, vasculitis, and autoimmune bullous diseases. Historically, dapsone was used for sleep disorders and then as an antibiotic to treat streptococcal infection, tuberculosis, and leprosy. Some dose-dependent adverse effects are well known, such as increased methemoglobinemia, hemolytic anemia, and neutropenia. Axonal neuropathy is a rare cumulative dose-related adverse effect attributed to direct drug toxicity, occurring after prolonged exposure. Idiosyncratic drug reactions have also been described such as dapsone hypersensitivity syndrome that appears in the few weeks after dapsone introduction, or hepatitis, which generally occurs within a few days after the start of treatment. We report a case of severe dapsone-induced hypoalbuminemia, a long-term drug reaction that can occur after a long delay, in a patient with mucous membrane pemphigoid.