Review Topic
  • A 3-year-old previously healthy boy is rushed to the emergency room for sudden-onset vomiting and lethargy. He was born at full-term without complications and had been meeting all milestones. Two weeks ago, he had headaches, myalgias, and fevers and tested positive for influenza A virus. At that time, his parents tried multiple anti-pyretic medications, including ibuprofen, acetaminophen, and aspirin. On physical exam, he is dehydrated and has hepatomegaly. Labs show increased liver enzymes and ammonia. A head computed tomography (CT) shows diffuse cerebral edema. He is admitted to the intensive care unit (ICU) and started on steroids.
  • Clinical definition
    • acute non-inflammatory hepatic encephalopathy resulting in fatty liver
  • Epidemiology
    • demographics
      • children
      • very rare
    • risk factors
      • viral infection treated with aspirin
        • varicella
        • influenza
        • gastroenteritis
        • rarely, vaccination with live viruses
  • Pathogenesis
    • aspirin metabolites inhibit mitochondrial enzymes
      • disrupts oxidative phosphorylation and fatty-acid beta-oxidation pathways
      • microvesicular fatty changes in the liver
  • Prognosis
    • mortality < 20%
  • Symptoms
    • nausea and sudden-onset vomiting
    • diarrhea
    • lethargy
    • irritability
    • restlessness
    • delirium
    • seizures
    • coma
  • Physical exam
    • hepatomegaly
    • minimal jaundice
    • obtunded
    • in severe cases
      • permanent neurologic damage
      • fixed and dilated pupils
      • loss of oculovestibular reflexes
  • Diagnostic testing
    • diagnostic approach
      • other causes of encephalopathy must be ruled out, including central nervous system infections
    • imaging
      • computed tomography (CT) of brain
        • diffuse brain swelling
    • studies
      • serum labs
        • ↓ blood glucose
        • ↑ ammonia
        • ↑ hepatic enzymes
        • ↑ long-chain free fatty acid levels
      • liver biopsy
        • non-inflammatory fatty changes
      • cerebral spinal fluid analysis
        • normal
  • Inborn errors of metabolism, e.g., fatty-acid oxidation defects, urea cycle defects, etc.
    • distinguishing factors
      • typically presents in infancy
      • genetic testing
      • normal liver size
  • Management approach
    • avoid use of aspirin in children, except when necessary, e.g., Kawasaki disease
    • treatment is largely supportive and neuro-protective
  • First-line
    • neuro-protection
      • modalities
        • mannitol
        • glycerol
        • dexamethasone
  • Permanent brain damage
  • Death

Please rate topic.

Average 4.8 of 6 Ratings

Thank you for rating! Please vote below and help us build the most advanced adaptive learning platform in medicine

The complexity of this topic is appropriate for?
How important is this topic for board examinations?
How important is this topic for clinical practice?
Topic COMMENTS (2)
Private Note