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Reye Syndrome

(Reye's Syndrome)


Christopher P. Raab

, MD, Sidney Kimmel Medical College at Thomas Jefferson University

Full review/revision Aug 2021 | Modified Sep 2022
Topic Resources

Reye syndrome is a very rare but life-threatening disorder that causes inflammation and swelling of the brain and impairment and loss of function of the liver.

  • The cause of Reye syndrome is unknown but it may be triggered by a viral infection and the use of aspirin.

  • Children typically have symptoms of a viral infection and then severe nausea, vomiting, confusion, and sluggishness, sometimes followed by coma.

  • The diagnosis is based on sudden changes in the child's mental condition and on the results of blood tests and a liver biopsy.

  • The prognosis depends on how long and how severely the brain is affected.

  • Treatment involves measures to lower pressure on the brain.

The cause of Reye syndrome is unknown, although it typically occurs after infection with certain viruses, such as influenza (flu) Influenza (Flu) Influenza (flu) is a viral infection of the lungs and airways with one of the influenza viruses. It causes a fever, runny nose, sore throat, cough, headache, muscle aches (myalgias), and a general... read more or chickenpox Chickenpox Chickenpox is a highly contagious viral infection with the varicella-zoster virus that causes a characteristic itchy rash, consisting of small, raised, blistered, or crusted spots. Chickenpox... read more Chickenpox , particularly in children who take aspirin during these infections. Because of this increased risk of triggering Reye syndrome, aspirin is not recommended for children, except for the treatment of Kawasaki disease Kawasaki Disease Kawasaki disease causes inflammation of blood vessels throughout the body. The cause of Kawasaki disease is unknown but may be associated with an infection. Children typically have fever, rash... read more Kawasaki Disease . Now that aspirin use has declined and chickenpox is less common because of vaccination, only about 2 children a year in the United States develop Reye syndrome. The syndrome occurs mainly in children younger than 18. In the United States, most cases occur in late fall and winter.


Reye syndrome varies greatly in severity. The syndrome begins with the symptoms of a viral infection, such as an upper respiratory tract infection, influenza, or sometimes chickenpox. After 5 to 7 days, the child suddenly develops very severe nausea and vomiting. Within a day, the child becomes sluggish (lethargic), confused, disoriented, and agitated. These changes in the child's mental condition are caused by increased pressure within the skull (intracranial pressure) and are sometimes followed by seizures Seizures in Children Seizures are a periodic disturbance of the brain’s electrical activity, resulting in some degree of temporary brain dysfunction. When older infants or young children have seizures, they often... read more , coma Stupor and Coma Stupor is unresponsiveness from which a person can be aroused only by vigorous, physical stimulation. Coma is unresponsiveness from which a person cannot be aroused and in which the person's... read more , and death.

In some children, the liver does not function correctly, which may lead to blood-clotting problems and bleeding and a buildup of ammonia in the blood.


  • Laboratory and imaging tests

  • Biopsy of the liver

Doctors suspect Reye syndrome in children who suddenly develop changes in mental condition and vomiting.

Once the diagnosis is confirmed, the level of severity is staged from I (lowest) to V (highest) based on the symptoms and test results.


The child’s prognosis depends on how long and how severely the brain was affected, whether the illness progressed to coma, the severity of increased pressure on the brain, and the level of ammonia in the blood.

The overall chances that the child will die are about 21% but range from less than 2% among children with mild disease (stage I) to more than 80% among children in a deep coma (stage IV or V). Many children who survive the acute phase of the illness recover fully. However, children who had more severe symptoms may later have signs of brain damage, such as intellectual disability, a seizure disorder, or muscle weakness. Abnormal muscle movement or damage to specific nerves may also occur.

Reye syndrome rarely affects a child twice.


  • Measures to lower pressure on the brain

There is no specific treatment for Reye syndrome.

Children are hospitalized and placed in an intensive care unit Types of units People who need specific types of care may be put in special care units. Intensive care units (ICUs) are for people who are seriously ill. These people include those who have had a sudden, general... read more . To reduce swelling and pressure on the brain, doctors may place a tube into the windpipe (endotracheal intubation) and provide a higher than normal breathing rate (hyperventilation), restrict fluids, elevate the head of the bed, and give drugs (such as mannitol) that force the body to get rid of water. Doctors also give dextrose to maintain a normal level of sugar (glucose) in the blood. Occasionally, doctors place a pressure-measuring device inside the head to monitor the increased pressure on the brain.

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