A delirious 8-year-old with influenza and noninflammatory CSF, liver enlargement, and vomiting—what is the most likely diagnosis?

A delirious 8-year-old with influenza and noninflammatory CSF, liver enlargement, and vomiting—what is the most likely diagnosis?

• A. Bacterial meningitis
• B. Guillain-Barre syndrome
• C. Measles encephalitis
• D. Reye's syndrome

Answer: (D)

This scenario points to Reye syndrome. It presents as acute encephalopathy (delirium in this child) that develops after a viral illness (influenza) and is accompanied by hepatic dysfunction (liver enlargement) and vomiting. The cerebrospinal fluid is noninflammatory, which argues against bacterial meningitis (which would typically show neutrophilic pleocytosis, higher protein, and often low glucose). Reye syndrome involves mitochondrial failure in the liver after a viral infection, and often after aspirin use in children, leading to microvesicular fatty changes, hyperammonemia, cerebral edema, and encephalopathy. The combination of recent viral illness, altered mental status, vomiting, and hepatomegaly with noninflammatory CSF is the pattern that makes Reye syndrome the most likely diagnosis.

This scenario points to Reye syndrome. It presents as acute encephalopathy (delirium in this child) that develops after a viral illness (influenza) and is accompanied by hepatic dysfunction (liver enlargement) and vomiting. The cerebrospinal fluid is noninflammatory, which argues against bacterial meningitis (which would typically show neutrophilic pleocytosis, higher protein, and often low glucose). Reye syndrome involves mitochondrial failure in the liver after a viral infection, and often after aspirin use in children, leading to microvesicular fatty changes, hyperammonemia, cerebral edema, and encephalopathy. The combination of recent viral illness, altered mental status, vomiting, and hepatomegaly with noninflammatory CSF is the pattern that makes Reye syndrome the most likely diagnosis.