Eosinophilic polymyositis induced by tranilast

A 38-year-old man with asthma developed eosinophilic polymyositis following the administration of Tranilast, an antiasthmatic agent. Low grade fever, erythematous rashes on the entire body, dysphagia, blood eosinophilia, elevations of serum creatine phosphokinase and myoglobin levels, and inverted T waves in the electrocardiogram were noted. A muscle biopsy showed focal degeneration of muscle fibers with an infiltrate of eosinophils and lymphocytes. A rechallenge with Tranilast resulted in erythema formation, blood eosinophilia, and elevations of some serum muscle enzymes and myoglobin levels. Tranilast was considered to be the causative agent. This is the first reported case of Tranilast-induced eosinophilic polymyositis.