Reye syndrome causes sudden brain and liver damage to infected. It occurs most often in children ages 4-12 years of age. It may follow an upper respiratory or viral infection such as chickenpox, and has symptoms of nausea, vomiting, seizures, confusion, and lethargy. As the disease worsens, the child may be unable to stay awake and alert. If left untreated, the disease can lead to severe brain damage and death.
Aspirin has been linked with Reye syndrome. Children and teenagers recovering from chickenpox or flu-like symptoms should not be given aspirin.