Reye's syndrome is a rare disorder that occurs after a viral infection. It results in sudden and severe decline in brain and liver function.

What is going on in the body?

Reye's syndrome can occur in individuals of any age following a viral illness. However, it is most common in children between the ages of 4 and 12. Studies have linked the syndrome to the use of aspirin by children who had chickenpox or other viral illnesses. Now children under the age of 19 are rarely given aspirin, and there are few cases reported each year.

It is not known how aspirin and certain viral infections change the way the body functions. It is known that damage occurs to the mitochondria, the tiny organs in each cell that control cell energy and breathing. Autopsies of people with Reye's syndrome have shown significant fatty buildup in liver and brain cells.

What are the causes and risks of the disease?

Reye's syndrome can develop in a person who hasn't taken aspirin. However, most individuals with the disease have recently used medicines containing aspirin or other salicylates. Viral infections associated with Reye's syndrome include the following: