Reye's syndrome in the British Isles: first annual report of the joint British Paediatric Association and Communicable Disease Surveillance Centre surveillance scheme.

Reye's syndrome is a severe acute paediatric disorder character- ised by encephalopathy with pronounced cerebral oedema and by diffuse fatty infiltration of the viscera, particularly the liver.'It may occur at any age in childhood.Typically a previously normal child has a viral type prodromal illness followed in a few days by vomiting, altered consciousness, and often convulsions.The liver may be enlarged and there may be evidence of hepatic dysfunction, with raised activities of transaminase, raised blood ammonia concentrations, and sometimes hypoglycaemia and a prolonged prothrombin time.At necropsy the liver is enlarged, pale, and fatty, and histological examination shows diffuse, panlobular microvesicular fatty infiltration.Fatty changes may also be seen in skeletal muscle, heart, and kidneys.Characteristic ultrastructural cellular changes have been described.2The aetiology of Reye's syndrome is unknown, but it is thought to represent an abnormal reaction to a viral infection in a genetically susceptible host, possibly modified by exo- genous toxins.3Influenza B and A and varicella zoster have been the most consistently associated viruses, although Reye's syndrome has been reported after many other viral infections.3Much of the epidemiological information about Reye's syndrome comes from the United States, where the Centers for Disease Control have maintained national surveillance for over 10 years.In Britain some data on Reye's syndrome in children under 3 years old were obtained from the National Childhood Encephalopathy Study.4In view of the lack of epidemiological knowledge about Reye's syndrome in children of all ages in the British Isles, a joint voluntary Reye's syndrome reporting scheme was started by the British Paediatric Associa- tion and the Communicable Disease Surveillance Centre in August 1981 with the aim of (a) documenting the occurrence and describing the characteristics of Reye's syndrome in the British Isles and monitoring long term trends; and (b) providing a central case register and serum and tissue bank for clinical or laboratory research.