Reversible valproate fulminant hepatic failure.

Valproate fulminant hepatotoxicity, usually fatal, is believed to be idiosyncratic and metabolic without an immunologic basis. There are no previous reports of a hypersensitivity reaction among numerous cases of fatal valproate fulminant hepatitis. Little is known about the electron microscopical features of valproate hepatitis. We report a case of reversible fulminant hepatitis attributable to valproate with clinical and histological characteristics of a hypersensitivity reaction. Electron microscopical findings included microvesicular steatosis with normal-appearing mitochondria.