Clinical Definition

Reyes syndrome is a rare, acute illness that produces a buildup of fat in the body’s organ systems. It primarily causes encephalopathy and brain damage, along with fatty degenerative liver failure. Typically, it affects children under the age of 15. The specific cause is not known, but an association with ingestion of salicylates after a viral illness, such as influenza, has been found.

In Our Own Words

Reyes syndrome is a rare condition that causes damage to the organ systems in the body. Although able to affect any organ system, it mainly affects the liver and the brain. It often causes brain swelling and impairs liver function.

The condition can come on suddenly and usually only affects children and teens under the age of 15. It typically begins when an individual is just starting to recover from a viral illness. The exact cause of Reyes syndrome has not been found, but children with certain inherited disorders of metabolism appear to be at greater risk. Also, a link was identified between Reyes syndrome and aspirin use in children with viral infections, especially the flu and chickenpox. Following the discovery of the condition’s connection with aspirin use in children, the number of cases of Reyes syndrome has decreased to a rate of one case per million children in the United States.