$Unique_ID{BRK04186} $Pretitle{} $Title{Reye Syndrome} $Subject{Reye Syndrome Hepatic Encephalopathy Liver Degeneration-Encephalopathy Fatty Liver with Encephalopathy Medium Chain CoA Dehydrogenase Deficiency} $Volume{} $Log{} Copyright (C) 1986, 1987, 1988, 1991, 1992 National Organization for Rare Disorders, Inc. 108: Reye Syndrome ** IMPORTANT ** It is possible the main title of the article (Reye Syndrome) is not the name you expected. Please check the SYNONYM listing to find the alternate names and disorder subdivisions covered by this article. Synonyms Hepatic Encephalopathy Liver Degeneration-Encephalopathy Fatty Liver with Encephalopathy Disorders section of this report. Medium Chain CoA Dehydrogenase Deficiency General Discussion ** REMINDER ** The information contained in the Rare Disease Database is provided for educational purposes only. It should not be used for diagnostic or treatment purposes. If you wish to obtain more information about this disorder, please contact your personal physician and/or the agencies listed in the "Resources" section. Reye Syndrome is a combination of acute brain disease (encephalopathy) and fatty degeneration of the abdominal organs (viscera), which tends to follow some acute virus infections (such as flu or chicken pox), combined with certain toxins (usually aspirin). Besides these viruses and toxins, deficiencies of the enzymes needed in the urea cycle appear to be a contributing factor to Reye Syndrome. Symptoms Vomiting after the onset of a viral illness is usually the first sign of Reye Syndrome. However, children under the age of 2 years may exhibit diarrhea and/or hyperventilation instead of vomiting. Next, behaviorial changes such as listlessness, sleepiness, irritability, aggressive and irrational behavior, and disorientation may occur. The child may then progress to a comatose state often within three to five days after the onset of symptoms. There may also be seizures. A complete recovery is possible. However, brain damage, ranging from a slight decrease in I.Q. to total paralysis, may occur. Causes Reye Syndrome appears to be caused by certain toxins given to individuals with a deficiency of enzymes needed in the digestive cycle. These enzymes break down the ammonium from proteins into urea which is excreted in the urine (urea cycle). This disorder is often associated with the use of aspirin to treat viral infections. The Centers for Disease Control, the AMA, and the American Academy of Pediatrics have issued statements warning against the use of aspirin in children with chickenpox and gastrointestinal flu-like illness. The FDA has also stated that medications such as tigan, compazine, thorazine and phenergan as well as other phenothiazines (a broad category of drugs) used to stop vomiting might possibly contribute to the severity of Reye Syndrome or mask its early symptoms. Except for aspirin, these drugs are only available by prescription. A recent scientific study indicated that ninety percent of children diagnosed with Reye Syndrome had taken salicylate drugs (such as aspirin) during the illness preceding onset of Reye's. The FDA considers this to be firm scientific evidence of the link between Reye Syndrome and aspirin. In 1990 researchers discovered that a few children who had died of Reye Syndrome lacked a certain enzyme that is needed to break down short-chain fatty acids. The beta oxidation defects cause fatty change in the liver muscle, and swelling of the brain. They suspect that this defect may only cause symptoms after a long period of fasting (not eating) which triggers low blood sugar and high concentrations of lactic acid in these children. The enzyme deficiency is inherited. However, more research is needed to confirm this theory. Affected Population Reye Syndrome occurs most frequently in white suburban children under the age of 16 years who have recently had viral illnesses such as chickenpox or influenza. However, it can also occur in newborns, adolescents, and even the middle-aged. The incidence of Reye Syndrome in teenagers has been rising in recent years, indicating that they may self-medicate with aspirin. The incidence of Reye Syndrome seems to be affected by the intensity and/or type of influenza activity year by year, according to the National Reye Syndrome Surveillance System. However, in 1984, influenza activity rose while reported cases of Reye Syndrome in children under ten years of age decreased. The number of cases in adolescents increased slightly. The decreased incidence for children under ten was apparent in cases with both chicken pox (varicella) and respiratory illness. Related Disorders Medium Chain CoA Dehydrogenase Deficiency is a very rare metabolic disorder characterized by a deficiency of the enzyme medium chain CoA dehydrogenase. This enzyme is needed in the breakdown (metabolism) of fats. Low blood sugar (hypoglycemia), lack of energy (lethargy) and possibly coma, associated with fatty changes in the liver, usually occur. During hypoglycemic periods, tests usually show massive amounts of dicarboxylic acid in the urine. (For more information on this disorder, choose "Medium Chain CoA" as your search term in the Rare Disease Database.) Therapies: Standard Reye Syndrome is diagnosed by liver function testing and the presenting symptoms. Immediate supportive treatment and care in an intensive care unit is vital for recovery since there is no known specific therapy for the disorder. Permanent neurological damage, such as mental impairment, can be present after recovery from the acute episode of the disease. Therapies: Investigational This disease entry is based upon medical information available through March 1991. Since NORD's resources are limited, it is not possible to keep every entry in the Rare Disease Database completely current and accurate. Please check with the agencies listed in the Resources section for the most current information about this disorder. Resources For more information on Reye Syndrome, please contact: National Organization for Rare Disorders (NORD) P.O. Box 8923 New Fairfield, CT 06812-1783 (203) 746-6518 National Reye Syndrome Foundation P.O. Box 829 Bryan, Ohio 43506 (419) 636-2679 NIH/National Institute of Neurological Disorders & Stroke (NINDS) 9000 Rockville Pike Bethesda, MD 20892 (301) 496-5751 (800) 352-9424 Centers for Disease Control (CDC) 1600 Clifton Road, N.E. Atlanta, GA 30333 (404) 639-3534 Office of Consumer Affairs (HFE-88) Food and Drug Administration 5600 Fishers Lane Rockville, MD 20857 References Budd, R., "Spotting Reye Syndrome while there's still time", RN, December, 1983. p. 39-42.