An acute encephalopathy with hepatic dysfunction stemming from mitochondrial damage.
Aetiology remains unknown, but viral infections, exogenous toxins, drugs, and inborn errors of metabolism have been implicated. Aspirin is classically associated but data are lacking for a definitive cause-effect relationship.
Usually presents with acute onset of profuse vomiting and altered mental status, ranging from a personality change to coma, in children recovering from a recent viral infection.
Laboratory findings include elevated ammonia, ALT/AST, and prolonged PT, without an increase in bilirubin. Liver biopsy shows steatosis without significant inflammation.
Treatment includes intensive supportive care, correction of metabolic abnormalities, and control of intracranial pressure.
Prognosis is generally good, and liver function returns to normal. However, encephalopathy can result in permanent neurological sequelae.
Reye's syndrome is an illness that meets all of the following criteria: an acute, non-inflammatory encephalopathy with either sterile CSF containing <9 WBC/mL or cerebral oedema without inflammatory cell infiltrate; hepatic dysfunction documented by either a threefold elevation of serum transaminases and/or serum ammonia, or liver biopsy demonstrating fatty infiltration; there is no other diagnosis to account for the cerebral and hepatic derangement.
History and exam
Key diagnostic factors
- presence of risk factors
- altered mental status
Other diagnostic factors
- abnormal pupillary response
- diminished pain response
- absence of, or minimal, jaundice and scleral icterus
- age 5-14 years
- white ethnicity
- recent viral infection
- aspirin (acetylsalicylic acid) and other drug exposure
- genetically predisposed individual
- toxin exposure
- winter/spring presentation
1st investigations to order
- serum electrolytes
- serum glucose
- serum ammonia
- urine/serum toxicology
- blood gas
Investigations to consider
- cranial CT
- lumbar puncture with cerebrospinal fluid analysis
- liver biopsy
- metabolic testing
- Head injury
- Acute bacterial meningitis
- Viral meningitis
- Management of children and young people with an acute decrease in conscious level
- Reye syndrome: 1990 case definition
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