Eosinophilic Pleurisy Induced by Dantrolene

A 70-year-old male developed eosinophilic pleurisy fifteen years after dantrolene sodium had been started for his spastic paraplegia due to spinocerebellar degeneration. Drug lymphocyte stimulation test (DLST) for dantrolene was positive. After discontinuance of dantrolene, pleural effusion gradually decreased and inflammatory reaction improved. During two-year observation, we have found no relapse of pleurisy without special medication. We present this case and compare this case with other 10 reported cases.