Reye's syndrome associated with acute myocarditis and fatal circulatory failure.

We describe an eight-month-old infant who had an unusually fulminant and fatal course of Reye's syndrome. The patient died 36 hours after admission because of irreversible circulatory failure not associated with clinical symptoms of increased intracranial pressure or cerebral herniation. Autopsy revealed the pathognomonic fatty degeneration of the liver and heart of Reye's syndrome, but the brain was normal. In addition, a marked inflammatory infiltration of the myocardium was also observed, which indicated that acute myocarditis had been the preceding underlying disease. This case report emphasizes the fact that the viral prodrome preceding Reye's syndrome may not be as benign as often observed with influenza and varicella. Acute myocarditis and Reye's syndrome are also a combination which may result in fatal cardiovascular collapse.