Reye syndrome is a rare but life-threatening condition primarily affecting children and adolescents, characterized by acute noninflammatory encephalopathy and fatty liver degeneration (microvesicular steatosis). It typically follows a viral illness (influenza B, varicella/chickenpox most commonly) and is strongly associated with aspirin (salicylate) use during the viral illness. The pathogenesis involves mitochondrial damage: aspirin metabolites (salicylate) are thought to uncouple oxidative phosphorylation and inhibit beta-oxidation of fatty acids in mitochondria, leading to impaired ATP production, intracellular fat accumulation (microvesicular steatosis in the liver), elevated ammonia (from disrupted urea cycle in damaged hepatocytes), and cerebral edema (from ammonia-induced astrocyte swelling and direct mitochondrial injury in neurons). The clinical course progresses rapidly through stages: Stage I — persistent vomiting, lethargy, and elevated liver enzymes; Stage II — hyperventilation, altered behavior, hepatic dysfunction; Stage III — coma, decerebrate posturing, and cerebral edema; Stages IV-V — deepening coma, seizures, and death from cerebral herniation. Since the public health campaign against giving aspirin to children with viral illness (1980s), the incidence has dropped dramatically from several hundred cases per year to fewer than 2 per year...