Reye’s Syndrome

Last Updated June 2023 | This article was created by editorial staff and reviewed by Kyle Bradford Jones, MD, FAAFP

What is Reye’s syndrome?

Reye’s syndrome is a rare but serious illness that can be harmful to the brain and the liver. It is most common in children, but anyone can get it. It is considered a two-phase illness because it typically occurs in children who are recovering from a viral infection. But it can occur three to five days after the start of the virus. Viruses could include a cold, the flu, or chickenpox. Also, it is commonly associated with the use of aspirin in children. You should avoid giving a child aspirin (salicylates) or over-the-counter medicines that contain salicylates to help prevent Reye’s syndrome.

Symptoms of Reye’s syndrome

The symptoms of Reye’s syndrome can be very mild and may go unnoticed. But they also can be very serious and worsen within hours, even to the point of death. That is why it’s important for parents to take symptoms of Reye’s syndrome seriously. If your child shows these symptoms, they need medical attention right away.

The most common symptoms include:

  • Vomiting that may last for hours
  • Personality changes, including irritability and aggressive behavior
  • Inability to stay alert or awake
  • Diarrhea and rapid breathing in children under 2 years old

Other symptoms could include:

  • Confusion
  • Lethargy
  • Weakness in the arms or legs
  • Speech difficulties
  • Double vision
  • Hearing loss
  • Seizures
  • Loss of consciousness or coma

What causes Reye’s syndrome?

Doctors aren’t sure exactly what causes Reye’s syndrome. But they have found that using aspirin to treat a viral illness increases the chances that a child will develop the condition. Now that doctors know this, parents should not give their children aspirin when sick. Fortunately, the number of cases of Reye’s syndrome have decreased. The condition is now very rare in the United States.

How is Reye’s syndrome diagnosed?

There is no one test for Reye’s syndrome. Diagnosis usually starts with blood and urine tests. Doctors may also test for metabolic disorders that could affect the liver. Sometimes more invasive tests are needed. This could include a spinal tap (lumbar puncture), liver biopsy, CT scan, or MRI. These tests can help the doctor rule out other conditions that could be causing the symptoms.

Can Reye’s syndrome be prevented or avoided?

The best way to avoid Reye’s syndrome is to avoid giving children aspirin, especially to treat symptoms of a viral illness. Unless instructed to do so by your child’s doctor, don’t give aspirin to any child under the age of 19. Always check the label before giving your child an over-the-counter medicine. Aspirin can be hidden in many medicines, such as Pepto-Bismol and Alka-Seltzer. Other names for aspirin include:

  • Acetylsalicylic acid
  • Acetylsalicylate
  • Salicylic acid
  • Salicylate

If your child has chickenpox, the flu, or another viral illness, you can treat fever and pain with other medicines. These include acetaminophen (1 brand name: Tylenol), ibuprofen (1 brand name: Advil), or naproxen (1 brand name: Aleve).

Another way to help prevent Reye’s syndrome is to prevent viral illnesses that can cause it. Make sure your child’s vaccinations are current. This includes 2 doses of the chickenpox vaccine and a yearly flu vaccine.

Reye’s syndrome treatment

There is no cure for Reye’s syndrome. Successful treatment depends on early diagnosis. Treatment usually happens in the hospital. If it is a severe case, your child may be treated in the intensive care unit (ICU). Treatments may include:

  • IV fluids. Your child may be hooked up to an intravenous (IV) line to give them fluids and keep them hydrated.
  • These medicines can be used to reduce the amount of pressure in the brain.
  • These could be used to reduce swelling in the brain.
  • Medicines to prevent bleeding. Abnormalities in the liver can cause bleeding, so medicines will be used to stop the bleeding.
  • If your child is having trouble breathing, they may need assistance from a breathing machine (ventilator).

Living with Reye’s syndrome

Reye’s syndrome is a serious illness that can cause major complications. A child’s recovery depends on how severe the swelling of the brain is. If the disease is caught early, swelling may not be significant. The child has a good chance of a full recovery. But if the disease reaches the later stages, a child may suffer brain damage and disability. In some cases, the child may die. That is why it is so important that you get medical help right away if you notice the symptoms of Reye’s syndrome in your child. Early detection and treatment can mean the difference between a full recovery and brain damage or death.

Questions to ask your doctor

  • What caused Reye’s syndrome in my child?
  • What kinds of tests will my child need to have?
  • How is this disease treated?
  • How long will it take for my child to recover?
  • Will my child have brain damage or disability?
  • What kind of follow-up care will my child need?
  • Which over-the-counter medicines have aspirin in them?


National Institutes of Health, MedlinePlus: Reye Syndrome

National Institute of Neurological Disorders and Stroke: Reye’s Syndrome

Reyes Syndrome Foundation


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