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Reye syndrome

Last reviewed: 30 Oct 2023
Last updated: 19 Apr 2023



History and exam

Key diagnostic factors

  • vomiting
  • altered mental status
More key diagnostic factors

Other diagnostic factors

  • hyperventilation
  • hepatomegaly
  • abnormal pupillary response
  • hyperreflexia/areflexia
  • diminished pain response
  • seizures
  • absence of, or minimal, jaundice and scleral icterus
Other diagnostic factors

Risk factors

  • age 5-14 years
  • white ethnicity
  • recent viral infection
  • aspirin (acetylsalicylic acid) and other drug exposure
  • genetically predisposed individual
  • toxin exposure
  • winter/spring presentation
More risk factors

Diagnostic investigations

1st investigations to order

  • serum electrolytes
  • serum glucose
  • LFTs
  • serum ammonia
  • PT/PTT
  • urine/serum toxicology
  • urinalysis
  • blood gas
More 1st investigations to order

Investigations to consider

  • cranial CT
  • lumbar puncture with cerebrospinal fluid analysis
  • EEG
  • liver biopsy
  • metabolic testing
More investigations to consider

Treatment algorithm


all patients



Vanessa G. Carroll, MD, FAAP

Medical Director of Pediatric Hospital Medicine

Kootenai Health

Coeur d’Alene



VGC declares that she has no competing interests.

Russell W. Steele, MD, FAAP

Section Head of Pediatric Infectious Diseases

Ochsner Medical Center for Children

New Orleans



RWS declares that he has no competing interests.


Dr Vanessa G. Carroll and Dr Russell W. Steele would like to gratefully acknowledge Dr Barry M. Starr, a previous contributor to this topic. BMS declares that he has no competing interests.

Peer reviewers

William F. Balistreri, MD

Professor of Pediatrics

Cincinnati Children's Hospital Medical Center




WFB declares that he has no competing interests.

Bernard Portmann, MD, FRCPath

Consultant Histopathologist

Institute of Liver Studies

King's College Hospital




BP declares that he has no competing interests.

  • Differentials

    • Head injury
    • Acute bacterial meningitis
    • Viral meningitis
    More Differentials
  • Guidelines

    • Management of children and young people with an acute decrease in conscious level
    • Reye syndrome: 1990 case definition
    More Guidelines
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