Metabolic disorders mimicking Reye's syndrome

Background: Several metabolic disorders such as encephalopathy and hepatic dysfunction have been described as Reye's-like syndrome because they presen t with similar clinical manifestations that mimic Reye's syndrome. We perfo rmed a retrospective study to explore the underlying metabolic etiologies o f Reye's-like syndrome in patients treated at National Taiwan University Ho spital. Methods: From January 1991 to June 1998, 19 children with a syndrome fittin g the Reye's-like syndrome description were identified for study. Urine org anic acid analysis, plasma amino acid analysis, liver pathology, and skin f ibroblast enzyme assays were studied during the acute stage of illness. Results: The etiologies of patients' syndromes included urea cycle disorder s (n = 7), glycogen storage disease type Ia ( 4), primary carnitine deficie ncy (2), hereditary fructose intolerance (1), methylmalonic acidemia (2), a nd 3-hydroxy-3-methylglutaric acidemia ( 1). Fatty acid oxidation defects w ere suspected in the remaining two cases. Conclusions: A significant number of patients who present with Reye's-like syndrome have an underlying inherited metabolic disorder. In patients with Reye's-like syndrome, an accurate diagnosis is essential to ensure normal g rowth and development and to prevent recurrence of the condition.