Reye syndrome

Disease Description (Causes and Symptoms)

• Definition summary: An acute hepatic encephalopathy in children that rarely occurs after an acute viral infection (primarily influenza or varicella), accompanied by microvesicular fatty change in the liver and cerebral edema.
• Causes/pathophysiology: Although the exact mechanism is unknown, the main mechanisms are hepatic metabolic abnormalities (impaired fatty acid oxidation) caused by mitochondrial dysfunction associated with viral infection, hyperammonemia, and the resulting cerebral edema and decreased brain function. Aspirin (salicylate) use is strongly associated with the risk of developing the condition.
• Main symptoms: Initially, vomiting and malaise, followed by rapidly progressing central nervous system symptoms such as lethargy, confusion, hallucinations, agitation, seizures, and coma. Hypoglycemia, jaundice, or signs of bleeding may occur, and in severe cases, death may occur within several hours to days.
• Test findings (useful information): Hypoglycemia, elevated AST/ALT (mild to moderate), increased blood ammonia, prolonged prothrombin time/INR, metabolic acidosis, and microvesicular fatty change in liver tissue. Cerebral edema may be observed on brain imaging (CT/MRI).

Treatment Methods and Precautions

• Basic principles: This is not a disease for which a specific antiviral drug exists; active supportive treatment centered in the emergency department and intensive care unit is the cornerstone of treatment.
• Acute-phase treatment
  • Emergency care: Immediately correct hypoglycemia (intravenous glucose). Support the airway and breathing (intubation and mechanical ventilation if necessary).
  • Intracranial pressure management: Elevate the head, provide sedation, use hyperosmolar therapy when possible (mannitol, hypertonic saline), manage positioning and body temperature, and consider intracranial pressure monitoring and surgical decompression when necessary (in severe cases).
  • Correction of metabolic and coagulation abnormalities: Correct electrolytes and acid-base abnormalities; administer vitamin K and fresh frozen plasma (when bleeding or prolonged prothrombin time is present); consider hemodialysis and liver support therapy in cases of severe liver failure.
  • Monitoring equipment: Repeatedly check blood glucose, ammonia, liver function, and coagulation tests, and continuously assess neurological status.
• Medications: Salicylate drugs such as aspirin, which may worsen Reye syndrome, are contraindicated. Steroids are not standard treatment, and consistent benefits have not been demonstrated.
• Complications and prognosis
  • Complications: Death due to severe cerebral edema, neurological sequelae after recovery (such as intellectual disability and motor impairment), and progressive liver failure.
  • Prognosis: Mild cases may recover within a short period, but when severe coma or seizures are present, the risks of death and permanent neurological damage are high.
• Self-care and precautions
  • Do not administer aspirin to children or adolescents with febrile illnesses without a doctor’s instructions (alternative antipyretics: acetaminophen or ibuprofen; follow age-specific and dosage instructions).
  • Immediately visit an emergency medical facility if abnormal vomiting, coma, or changes in consciousness occur after a fever or viral illness.

Checklist Before an Outpatient Visit (Items to Prepare and Example Questions)

• Items/documents to prepare
  • A list of all medications currently being taken (including prescription drugs, over-the-counter drugs, and supplements)
  • Medical history related to recent fever, respiratory symptoms, varicella, and contact history (exposure to infection), including when symptoms began
  • Whether antipyretics (especially aspirin) were taken, and the time and dosage taken
  • Bring recent test results (such as liver function, blood glucose, and coagulation tests) or hospital records if available
  • Photos taken when symptoms occurred and a symptom diary (such as the number of vomiting episodes and the time of changes in consciousness)
• Items to confirm in advance at the outpatient visit (recommended for patients and caregivers)
  • The medications taken recently and the exact times they were taken
  • The time symptoms (vomiting, drowsiness, confusion, seizures, etc.) began and how they progressed
  • Family history (metabolic diseases, epilepsy, etc.)

Examples of General Questions to Ask the Doctor

• "Based on the current symptoms, how likely is this diagnosis? What additional tests are needed?"
• "What is the acute-phase treatment plan, and how long is the expected hospital stay?"
• "What are the main side effects of this medication (or treatment), and what should be monitored?"
• "What precautions should be taken when returning to daily activities after recovery, and what is the schedule for follow-up tests?"

Examples of Disease-Specific Questions

• "During the recent febrile illness, did you take aspirin or any salicylate-based medication? If so, please tell us the exact time and dosage taken."
• "Can we review the blood test results (especially blood glucose, ammonia, AST/ALT, and INR)? If the levels have changed, this will significantly affect the possibility of recovery and the treatment approach."