Reye syndrome is a very rare but serious disease that is most likely to occur in children younger than 15 years of age. The exact cause is not known, but it is linked with children who have recently had chickenpox (varicella), a cold, or flu (influenza) and taken aspirin.

The disease primarily targets the brain and liver and can cause drowsiness, confusion, seizures, coma, and in severe cases, death. The symptoms usually develop 3 to 7 days after the viral illness starts. Reye syndrome is not contagious.

All children with Reye syndrome are treated in a hospital intensive care unit, and most recover in a few weeks. But some children develop lasting brain damage. Early treatment increases the chance for full recovery.

Aspirin or aspirin products should not be given to anyone younger than 20, unless they are specifically prescribed by a doctor. Aspirin is also called ASA, acetyl salicylate, acetylsalicylic acid, salicylic acid, salicylate, or subsalicylate. Aspirin products are found in over-the-counter medicines such as Pepto-Bismol and Alka-Seltzer.