Reye syndrome is a very rare disorder that damages many parts of the body, especially the brain and the liver. For unknown reasons, the parts of the cells that make energy (mitochondria) stop working correctly, which causes severe illness. The most serious problems are swelling of the brain and problems with the breakdown of fat, which results in build up in the liver and other organs. The illness can be fatal, especially if not detected early and treated appropriately.
Although Reye syndrome can occur at any age, it most often affects children between the ages of 3 and 12.
Reye syndrome typically occurs several days after the child is recovering from a viral infection, such as the flu, common cold, or chickenpox. It also can develop while the child is still sick, a few days after the viral illness began. While the exact cause of Reye syndrome is not known, researchers believe that it may be due to an abnormal response to aspirin or aspirin-containing products taken during a viral illness. For this reason, never give aspirin or aspirin-containing medicines to children with fever or a flu-like illness.