Reye syndrome is a potentially fatal disease of childhood, characterized by a combination of acute encephalopathy and fatty infiltration of the internal organs. The etiology is unknown, but it is almost always associated with a previous viral infection.
The symptomatology of Reye syndrome typically surfaces after 3 to 5 days from onset of the viral infections of the respiratory tract. The following system wise presentation of signs and symptoms is commonly seen in patients with Reye syndrome:
The diagnosis of Reye syndrome conforms with the diagnostic criteria established by the CDC which in includes: acute altered state of consciousness, hepatic dysfunction, CSF white blood cell count of less than 8 cells/uL, and histologic signs of cerebral edema . Reye syndrome does not have a specific test to clinch its definitive diagnosis. However, there are laboratory tests that may correlate with the syndrome and aid the management of cases. The following laboratory examinations and tests are done in patients with relative risk for Reye syndrome:
Patients suffering from Reye syndrome are always treated as an in-patient case in the hospital although severe cases may require intensive care. The following specific treatments are implored in the treatment of Reye syndrome among admitted patients:
Prognosis and mortality rates greatly improve with the prompt diagnosis and treatment of Reye syndrome. The majority of deaths in Reye syndrome is due to cerebral edema; thus, any signs of increased intracranial pressure precludes a poor prognosis .
Age related risk for mortality is marked below 5 years of age. Serum ammonia levels beyond 45 mcg/dl have a relative risk of 3.4. Hypoglycemia and hyponatremia are considered early predictors of poor prognosis.
The following clinical conditions are established complications of Reye syndrome:
The definitive etiology of Reye syndrome is vaguely understood. However, salicylates like aspirin and viral infections like influenza and varicella are identified as a triggering factor in the onset of the disease among teenagers and children .
Inborn error of metabolism like the medium-chain-acyl-dehydrogenase and the long-chain-acyl-dehydrogenase deficiency has been proven to cause Reye syndrome among patients . The exposure to toxins like insecticides, herbicides and paint thinner have also been implicated in the occurrence of Reye syndrome.
The peak annual incidence of Reye syndrome in the United States reached 555 cases between 1979 and 1980 according to the Centers of Disease and Control (CDC). The national prevalence in the United States is 15 to 88 cases per 10 million population.
Prevalence of Reye syndrome correlates well during the outbreaks of influenza and chicken pox. In the United Kingdom, the incidence of Reye syndrome occurs among children ages 12 and below at 63 cases per 10 million population .
Peak age incidence of Reye syndrome is at 6 years old with age range incidence at 5 to 14 years old. Reye syndrome rarely affects the newborns and those beyond the age of 18 years old. The white race shares 93% of cases while the black African American race has only 5% of the cases.
The exact pathophysiology of Reye syndrome is still unclear although mitochondrial injury and dysfunction has been closely implicated. There is a marked inhibition of the oxidative phosphorylation and the fatty acid beta oxidation in cells which were previously infected by the flu and chicken pox virus.
Mitochondrial dysfunction are further aggravated by toxins like salicylates. The progressive damage of the hepatic mitochondria leads to hyperammonemia causing astrocyte and cerebral edema causing an increased in intracranial pressure in the brain.
Extreme precautions should be observed in giving aspirin to children especially those recovering from a recent viral infection. Newborn screening can detect inborn errors of metabolism that can greatly predispose the child to Reye syndrome. A careful examination of the drug labels should be a prudent practice to prevent inadvertent intake of aspirin during viral infections. The active immunization against varicella and influenza can greatly lower the incidence of Reye syndrome among children.
Reye syndrome is a rare and serious clinical disease characterized by the progressive swelling of the liver and the brain. This syndrome commonly affects children and teenagers with recent viral infection like influenza and varicella .
Patients may appear unconscious in the emergency room which requires immediate care of this potentially fatal disease . Aspirin is commonly associated with Reye syndrome; thus, prudent caution should be observed when giving this type of medications to pediatric cases who are undergoing a viral infection.
A good clinical history and neurologic examination, blood tests, liver and skin biopsy, and imaging methods are used to diagnose Reye syndrom.
Treatment and follow-up