Reye Syndrome

Overview

Reye syndrome is a rare but potentially life-threatening condition that causes rapid swelling of the brain (encephalopathy) along with a buildup of fat in the liver. It most often appears in children and teenagers who are recovering from a viral infection such as the flu or chickenpox, particularly when aspirin has been used to treat the illness.

Because of this link, public health agencies have warned for decades against giving aspirin to children and teens during viral infections. Since that guidance became widespread, the condition has become very uncommon. Even so, Reye syndrome remains a medical emergency: it can progress quickly, and early recognition and hospital care greatly improve the chance of recovery.

Symptoms

Symptoms typically begin a few days after a viral illness seems to be improving. They tend to develop in stages and can worsen rapidly.

• Persistent or repeated vomiting
• Unusual sleepiness, lethargy, or loss of energy
• Confusion, irritability, or aggressive behavior
• Disorientation and difficulty recognizing people
• Seizures or convulsions
• Loss of consciousness

In infants, the pattern may differ and can include diarrhea and rapid breathing rather than vomiting. Any child who develops repeated vomiting or a change in mental state after a viral illness needs urgent medical evaluation.

Causes

The exact cause of Reye syndrome is not fully understood. It appears to involve damage to the tiny energy-producing structures inside cells, called mitochondria, which are especially important in the liver and brain. When these are injured, the liver cannot clear waste products such as ammonia from the blood, and the resulting buildup contributes to brain swelling.

The strongest known trigger is the use of aspirin (and other salicylate-containing products) during a viral infection such as influenza or chickenpox. Some children later found to have an underlying inherited metabolic disorder can develop a similar illness, so testing for these conditions is often part of the evaluation.

Risk Factors

• Taking aspirin or salicylate-containing medicines during a viral illness
• Recent viral infection such as influenza or chickenpox
• Being a child or teenager (the condition is rare in adults)
• An undiagnosed inherited disorder of fatty acid or metabolic processing

It is worth checking labels carefully, because aspirin and salicylates appear in some combination cold and flu remedies and stomach products under names other than "aspirin."

Diagnosis

There is no single test for Reye syndrome, so doctors diagnose it from the pattern of illness combined with blood tests and other studies, while ruling out infections and metabolic disorders that can look similar.

• Blood tests: To check liver function, blood ammonia, blood sugar, and clotting.
• Lumbar puncture: Examining spinal fluid to rule out meningitis or encephalitis.
• Liver biopsy: Occasionally used to confirm the typical fatty changes.
• Brain imaging: CT or MRI to assess brain swelling and exclude other causes.
• Metabolic screening: To look for an underlying inherited disorder.

Treatment

Reye syndrome is treated in the hospital, often in an intensive care unit, because the condition can change quickly. There is no specific cure, so care focuses on supporting the body and protecting the brain while the illness runs its course.

• Intravenous fluids and glucose: To maintain blood sugar, salts, and hydration.
• Controlling brain swelling: Medicines and careful monitoring to manage pressure inside the skull.
• Supporting clotting and the liver: Vitamin K, plasma, or other products if bleeding risk is high.
• Breathing support: A ventilator may be needed if breathing or consciousness is affected.

With early diagnosis and prompt intensive care, many children recover, although severe cases can cause lasting brain injury.

Prevention

• Do not give aspirin or salicylate-containing products to children or teenagers, especially during or after a viral illness, unless a doctor specifically directs it for another condition
• Use acetaminophen or ibuprofen for fever and pain in children instead, as advised by a clinician
• Read medicine labels carefully, since salicylates appear in some combination cold, flu, and stomach remedies
• Keep up with recommended vaccinations against influenza and chickenpox to reduce the viral illnesses that can trigger the condition

When to See a Doctor

Seek emergency medical care immediately if a child or teenager who is recovering from a viral illness develops:

• Repeated or persistent vomiting
• Unusual drowsiness, confusion, or difficulty waking
• Personality changes, irritability, or aggressive behavior
• Seizures or loss of consciousness

Do not wait to see whether symptoms improve. Call emergency services or go to the nearest emergency department, as early treatment can be life-saving.

Related Topics

Frequently Asked Questions

References

1. National Institute of Neurological Disorders and Stroke (NINDS). Reye's Syndrome.
2. Mayo Clinic. Reye's syndrome — Symptoms and causes.
3. Centers for Disease Control and Prevention (CDC).
4. MedlinePlus, U.S. National Library of Medicine. Reye syndrome.