Reye's syndrome is a disorder principally affecting the liver and brain, marked by rapid development of life-threatening neurological symptoms.
Reye's syndrome is an emergency illness chiefly affecting children and teenagers. It almost always follows a viral illness such as a cold, the flu, or chickenpox . Reye's syndrome may affect all the organs of the body, but it most seriously affects the brain and liver. Brain swelling and massive accumulations of fat in the liver and other organs lead to the rapid development of severe neurological symptoms, including lethargy, confusion, seizures, and coma. Reye's syndrome is a life-threatening emergency, with a fatality rate of about 30 to 50 percent.
Reye's syndrome is a rare illness, even rarer in the early 2000s than when it was first described in the early 1970s. The incidence of the disorder peaked in 1980, with 555 cases reported. The number of cases declined rapidly thereafter once researchers made the association between aspirin use and the development of Reye's syndrome. Cases dropped precipitously when parents and healthcare providers were clearly warned against using any aspirin-containing products in children. As of 2004, fewer than 20 cases of Reye's syndrome are reported annually. Because of the rarity of Reye's syndrome, it is often misdiagnosed as encephalitis , meningitis , diabetes, or poisoning , and the true incidence may be higher than the number of reported cases indicates.
Causes and symptoms
Reye's syndrome causes fatty accumulation in the organs of the body, especially the liver. In the brain, it causes fluid accumulation (edema), which leads to a rise in pressure in the brain (intracranial pressure). This pressure compresses blood vessels, preventing blood from entering the brain. Untreated, this pressure increase leads to brain damage and death.
Although as of 2004 the cause remains unknown, Reye's syndrome appears to be linked to an abnormality in the energy-converting structures (mitochondria) within the body's cells.
Reye's syndrome usually occurs after a viral illness with fever , most often an upper respiratory tract infection. It is most often associated with use of aspirin during the fever, and for this reason aspirin and aspirin-containing products are not recommended for people under the age of 19 during fever. Although rare, Reye's syndrome may occur without aspirin use and in adults.
After the beginning of recovery from the viral illness, the affected person suddenly becomes more ill again, with the development of persistent vomiting . This may be followed rapidly by quietness, lethargy, agitation or combativeness, seizures, and coma. In infants, diarrhea may be more common than vomiting. Fever is usually absent at this point.
Reye's syndrome may be suspected in a child who begins vomiting three to six days after a viral illness, followed by an alteration in consciousness. Diagnosis involves blood tests to determine the levels of certain liver enzymes, which are highly elevated in Reye's syndrome. Other blood changes may occur as well, including an increase in the level of ammonia and amino acids, a drop in blood sugar, and an increase in clotting time. A liver biopsy may also be done after clotting abnormalities are corrected with vitamin K or blood products. A lumbar puncture (spinal tap) may be needed to rule out other possible causes, including meningitis or encephalitis.
Reye's syndrome is a life-threatening emergency that requires intensive management. The likelihood of recovery is greatest if it is recognized early and treated promptly. Children with Reye's syndrome should be managed in an intensive-care unit.
Treatment in the early stages includes intravenous sugar to return blood sugar levels to normal and plasma transfusion to restore normal clotting time in the blood. Intracranial pressure is monitored and, if elevated, is treated with drugs such as mannitol and barbiturates placing the patient on a ventilator so that hyperventilation can be used.
The mortality rate for Reye's syndrome is between 30 and 50 percent. The likelihood of recovery is increased to 90 percent by early diagnosis and treatment. Almost all children who survive Reye's syndrome recover fully, although recovery may be slow. In some patients, permanent neurologic damage may remain, requiring physical or educational special services and equipment.
Because Reye's syndrome is so highly correlated with use of aspirin for fever in young people, avoidance of aspirin use by children is strongly recommended. Aspirin is in many over-the-counter and prescription drugs, including drugs for headache , fever, menstrual cramps, muscle pain , nausea , upset stomach, and arthritis. It may be used in drugs taken orally or by suppository.
Any of the following ingredients indicates that aspirin is present:
- acetylsalicylic acid
- salicylic acid
Teenagers who take their own medications without parental consultation should be warned not to take aspirin-containing drugs.
Acetylsalicylic acid —Aspirin; an analgesic, antipyretic, and antirheumatic drug prescribed to reduce fever and to relieve pain and inflammation.
Edema —The presence of abnormally large amounts of fluid in the intercellular tissue spaces of the body.
Mitochondria —Spherical or rod-shaped structures of the cell. Mitochondria contain genetic material (DNA and RNA) and are responsible for converting food to energy.
Michaels, Marian G. "Reye Syndrome." In Principles and Practice of Pediatric Infectious Diseases , 2nd ed. Edited by Sarah S. Long et al. St. Louis, MO: Elsevier, 2003.
Rudolph, Jeffrey A., and William F. Balistreri. "Reye's Syndrome and the Mitochondrial Hepatophathies." In Nelson Textbook of Pediatrics. Edited by Richard E. Behrman et al. Philadelphia: Saunders, 2004.
National Reye's Syndrome Foundation. PO Box 829, Bryan, OH 43506-0829. Web site: http://www.reyessyndrome.org.
Richard Robinson Rosalyn Carson-DeWitt, MD