Reye Syndrome
May 12, 2004, KidsHealth.org

Signs and Symptoms
The signs and symptoms of Reye syndrome are almost always preceded by a viral illness. This could be an upper respiratory tract infection, diarrhea of infectious origin, or chicken pox (Reye syndrome symptoms usually appear three to five days after the onset of the chicken pox rash). Many cases are mild and may even go undetected; others may be severe, requiring aggressive care.

Symptoms include nausea, vomiting, lethargy and indifference. The child may exhibit irrational behavior or delirium, and rapid breathing. In the later stages, breathing becomes sluggish and the child becomes comatose, with dilated pupils. The liver may be enlarged, but there is usually no jaundice or fever.

Reye syndrome is rare: approximately 0.1 case per 100,000 population. It is, however, often thought of when a child has continual vomiting or change of mental status - particularly after a recent viral illness.

Although severity varies, Reye syndrome should be considered an acute disorder that is potentially life threatening.

Description
In 1963, a North Carolina doctor reported an epidemic of 16 fatal cases of an encephalitis-like illness during an influenza B outbreak. It became known as Reye syndrome. The syndrome had been reported as early as 1929 but now was identified and characterized as a distinct entity. In the late 1960s the Centers for Disease Control and Prevention developed case criteria that included mental status changes (delirium or coma) and a liver biopsy that showed fat accumulation in the liver (or high levels of liver enzymes and ammonia in the blood).

Reye syndrome is still not well understood. It predominantly affects children between four and 16 years, and is more frequent when viral diseases are epidemic, such as the winter months or following an outbreak of chicken pox or influenza B.

The use of salicylates like aspirin during viral disease appears to be statistically linked to the incidence of Reye syndrome, even though there is no conclusive proof.

No single diagnostic test to detect Reye syndrome currently is available.

Prevention
Aspirin and other salicylate drugs should never be used in the treatment of chicken pox, influenza and other viral diseases. Aspirin is not recommended in any illness contracted by children younger than age 12.

Incubation
Reye syndrome can occur several days (range: 1-14 days) after a viral infection; the majority of cases seem to occur within a two-month period.

Duration
The duration varies with the severity of the disease. Reye syndrome can be mild and self-limiting, or, rarely, can progress to death within hours. But the progression may stop at any stage, with complete recovery in five to 10 days.

Contagiousness
The viral illnesses that lead to Reye syndrome are contagious; the syndrome itself is noncontagious.

Home Treatment
Children with Reye syndrome are usually treated in a hospital; if seriously ill, in a hospital intensive care unit.

Professional Treatment
Treatment is supportive rather than to "cure" the illness. The clinical care team focuses on making sure the patient with Reye syndrome maintains proper fluid and electrolyte balance, nutritional, and cardiorespiratory status. With these systems being in the best possible balance, the child stands the best chance of recovery.

Seriously ill children will require intensive monitoring during this syndrome. A variety of catheters (nasogastric tubes, urinary catheters, and the like) may need to be placed to monitor and control fluids, electrolytes, blood gas status and nutrition. Patients are not given any food by mouth, only intravenous nutritional fluids. The fluids are also selected to ensure a proper electrolyte balance. (Electrolytes enhance cell nutrition, and help control water balance outside and inside cell walls.)

Mechanical ventilation (a breathing machine or respirator) may be necessary if breathing becomes too sluggish. Intracranial pressure (pressure of the fluid within the central nervous system within the skull) and blood pressure may be monitored. The body may be cooled and drugs like barbiturates given in order to slow metabolism and decrease intracranial pressure. Small quantities of insulin may be given to increase glucose metabolism, corticosteroids to reduce brain swelling and diuretics to increase fluid loss.

The prognosis for children with Reye syndrome has improved. Earlier diagnosis and better treatment have reduced the mortality rate to about 20% in recent years. The earlier the syndrome is detected, the better the chances for survival. Children who progress to the late stages of the syndrome may have continuing neurological defects.

When to Call Your Child's Doctor
Incidence of Reye syndrome has fallen dramatically since its discovery. If, however, following a viral illness such as the flu or a cold, your child shows symptoms of nausea, vomiting or behavioral changes, contact your doctor immediately. Of course, many children with viruses will have some of these symptoms. Most will not have Reye syndrome. Nevertheless, early detection is the key to successful treatment of Reye syndrome.