Snapshot 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. Introduction Clinical definition login to view 1 more bullet Epidemiology Demographics login to view 2 more bullets Risk factors login to view 5 more bullets ETIOLOGY Pathogenesis login to view 3 more bullets Presentation Symptoms login to view 8 more bullets Physical exam login to view 7 more bullets imaging Computed tomography (CT) of brain login to view 1 more bullet Studies Diagnostic testing login to view 12 more bullets Differential Inborn errors of metabolism, e.g., fatty-acid oxidation defects, urea cycle defects, etc. login to view 4 more bullets Treatment Management approach login to view 2 more bullets First-line login to view 5 more bullets Complications Permanent brain damage Death Prognosis Mortality < 20%