Reye's syndrome is an acute disorder which affects patients apparently recovering from a viral illness like 'flu', chickenpox or gastroenteritis. Unless diagnosed and treated successfully, death or severe disability may result.
The patient has a change in his/her personality or becomes drowsy or unconscious and develops frequent or persistent effortless vomiting. There is disordered liver function with raised serum hepatic transaminases and hyperammonaemia without hyperbilirubinemia. There is often hypoglycaemia and disordered clotting. Abnormal accumulations of fat develop in the liver and some other organs of the body. There is also cerebral oedema which may cause permanent brain injury or death if treated inadequately.
The disease affects children from infancy onwards, including teenagers, and has been reported, albeit rarely, in adults. Children of both sexes and all races can be affected.