National Reyes Syndrome Foundation UK

Second level navigation header

Information for Parents, Young Adults and General Public

Signs and Symptoms - What are the early stages of Reye's Syndrome?

The symptoms of Reye's syndrome begin a few days after a viral infection.

Persistent or continuous vomiting and/or:

Signs of cerebral oedema (brain swelling):-

  • Listlessness (a lack of interest or enthusiasm)
  • Loss of Energy
  • Drowsiness
  • Delirium (a severe state of mental confusion and anxiety sometimes associated with hallucinations)
  • Convulsions (fits)
  • Coma

Personality changes:-

  • Irritability
  • Aggressive behaviour
  • Disorientation
  • Confusion
  • Irrational behaviour

Reye's syndrome should be suspected if a child displays all or part of this pattern of symptoms a few days after the onset of a viral infection such as 'flu' or chickenpox. Fever is not usually present. Many diseases have similar features. Medical staff who do not have experience of Reye's syndrome may initially suspect encephalitis (inflammation of the brain), meningitis (inflammation of the protective membranes surrounding the brain and spinal chord), poisoning, mental illness or even drug abuse. In infants the symptoms of Reye's syndrome may not follow a typical pattern; for example vomiting is less common. However it should be emphasised that it is in infants that the "Reye-like syndromes" are most likely to occur.


Next review December 2019