Very rare rapidly progressive encephalopathy usually beginning shortly after recovery from acute viral illness, especially influenza and varicella, with rash, vomiting, and liver damage.Encyclopedia Entry for Reye Syndrome :Reye syndrome - resources. Resources - Reye syndrome.Encyclopedia Entry for Reye Syndrome :Reye syndrome. There is no known cause of Reye syndrome. It is most often seen in children ages 4 to 12. Most cases that occur with chickenpox are in children ages 5 to 9. Cases that occur with the flu are most often in children ages 10 to 14.Children with Reye syndrome get sick very suddenly. The syndrome often begins with vomiting. It may last for many hours. The vomiting is quickly followed by irritable and aggressive behavior. As the condition gets worse, the child may be unable to stay awake and alert. Other symptoms of Reye syndrome: Confusion Lethargy Loss of consciousness or coma Mental changes Nausea and vomiting Seizures Unusual placement of arms and legs ( decerebrate posture ). The arms are extended straight and turned toward the body, the legs are held straight, and the toes are pointed downward Other symptoms that can occur with this disorder include: Double vision Hearing loss Muscle function loss or paralysis of the arms or legs Speech difficulties Weakness in the arms or legs.The following tests may be used to diagnose Reye syndrome: Blood chemistry tests Head CT or head MRI scan Liver biopsy Liver function tests Serum ammonia test Spinal tap.There is no specific treatment for this condition. The health care provider will monitor the pressure in the brain, blood gases , and blood acid-base balance (pH). Treatments may include: Breathing support (a breathing machine may be needed during a deep coma) Fluids by IV to provide electrolytes and glucose Steroids to reduce swelling in the brain.How well a person does depends on the severity of any coma, as well as other factors. The outcome for those who survive an acute episode may be good.Complications may include: Coma Permanent brain damage Seizures When untreated, seizures and coma may be life threatening.Go to the emergency room or call the local emergency number (such as 911) immediately if your child has: Confusion Lethargy Other mental changes.Never give a child aspirin unless told to do so by your provider. When a child must take aspirin, take care to reduce the child's risk of catching a viral illness, such as the flu and chickenpox. Avoid aspirin for several weeks after the child has received a varicella (chickenpox) vaccine. Note: Other over-the-counter medicines, such as Pepto-Bismol and substances with oil of wintergreen also contain aspirin compounds called salicylates. DO NOT give these to a child who has a cold or fever.Digestive system organs Digestive system organs.Ferri FF. Reye's syndrome.