Reye's syndrome

Definition

Reye's syndrome is a disorder principally affecting the liver and brain, marked by rapid development of life-threatening neurological symptoms.

Description

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 chicken pox. Reye's syndrome may affect all the organs of the body, but most seriously affects the brain and liver. Rapid development of severe neurological symptoms, including lethargy, confusion, seizures, and coma, make Reye's syndrome a life-threatening emergency.

Reye's syndrome is a rare illness, even rarer now than when 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 due to decreased use of aspirin compounds for childhood fever, an important risk factor for Reye's syndrome development. Because of its rarity, 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 & 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 intracranial pressure. This pressure squeezes blood vessels, preventing blood from entering the brain. Untreated, this pressure increase leads to brain damage and death.

Although 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, fever-causing illness, most often an upper respiratory tract infection. Its cause is unknown. 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. Reye's syndrome may occur without aspirin use, and in adults, although very rarely.

After the beginning of recovery from the viral illness, the affected person suddenly becomes worse, 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.

Diagnosis

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.

Treatment

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 levels to normal and plasma transfusion to restore normal clotting time. Intracranial pressure is monitored, and if elevated, is treated with intravenous mannitol and hyperventilation to constrict the blood vessels in the brain. If the pressure remains high, barbiturates may be used.

Prognosis

The mortality rate for Reye's syndrome is between 30-50%. The likelihood of recovery is increased to 90% 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.

Prevention

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 thata spirin is present:

• Aspirin
• Acetylsalicylate
• Acetylsalicylic acid
• Salicylic acid
• Salicylate.

Teenagers who take their own medications without parental consultation should be warned not to take aspirin-containing drugs.

Key Terms

Acetylsalicylic acid

Aspirin; an analgesic, antipyretic, and antirheumatic drug prescribed to reduce fever and for relief of pain and inflammation.

Edema

The abnormal accumulation of fluid in interstitial spaces of tissue.

Mitochondria

Small rodlike, threadlike, or granular organelle witin the cytoplasm that function in metabolism and respiration.

Further Reading

For Your Information

Books

• Hurst, John Willis, ed., et al. Medicine for the Practicing Physician, 4th ed. Stamford, CT: Appleton and Lange, 1996.
• Schiff, E. and L. Schiff, eds. Diseases of the Liver, 7th ed. Philadelphia, PA: J.B. Lippincott, 1993.

  Organizations

• National Reye's Syndrome Foundation. PO Box 829, Bryan, OH 43506-0829. (800) 233-7393. http://www.bright.net/~reyessyn/.

Gale Encyclopedia of Medicine. Gale Research, 1999.