A 9-year-old previously healthy boy is brought to the emergency department with a 7-day history of fever, malaise, anorexia, nausea, and vomiting. Three days later, his parents noticed yellow discoloration of the eyes and dark-colored urine. Today, he became increasingly drowsy and irritable and had difficulty recognizing family members.
On examination:
Temperature: 37.8°C
Heart rate: 90/min
Blood pressure: 100/60 mmHg
He is confused and disoriented to time and place.
Scleral icterus is present.
Liver is palpable 2 cm below the costal margin and tender.
No splenomegaly or ascites.
Asterixis is present.
Investigations:
Total bilirubin: 12.8 mg/dL
ALT: 1850 IU/L
AST: 1620 IU/L
INR: 2.4
Serum ammonia: Elevated
Blood glucose: 68 mg/dL
Serum creatinine: 0.7 mg/dL
Which of the following is the most appropriate diagnosis?
A. Acute liver failure secondary to acute viral hepatitis
B. Acute-on-chronic liver failure
C. Hepatic encephalopathy due to Wilson disease
D. Septic encephalopathy
E. Reye syndrome
Correct answer & Explanation:
Correct Answer: A. Acute liver failure secondary to acute viral hepatitis
Discussion: Acute viral hepatitis leading to acute liver filure
This child has classical features of acute viral hepatitis complicated by acute liver failure (ALF):
Prodrome of fever, malaise, anorexia, nausea, and vomiting
Development of jaundice
Altered sensorium and asterixis (hepatic encephalopathy)
Markedly elevated transaminases
Coagulopathy (INR >1.5)
No evidence of pre-existing chronic liver disease
The diagnosis of acute liver failure in children is based on:
No known chronic liver disease.
Biochemical evidence of acute liver injury.
Coagulopathy (INR ≥1.5 with encephalopathy, or INR ≥2 without encephalopathy).
This patient fulfills all criteria.
Why the Other Options Are Incorrect
B. Acute-on-chronic liver failure
Requires underlying chronic liver disease, which is absent.
C. Hepatic encephalopathy due to Wilson disease
Usually presents with Coombs-negative hemolytic anemia, low alkaline phosphatase, Kayser-Fleischer rings, or chronic liver disease features.
D. Septic encephalopathy
Does not explain severe jaundice, markedly elevated transaminases, and significant coagulopathy.
E. Reye syndrome
Typically follows aspirin exposure during a viral illness and presents with hyperammonemia but usually without marked jaundice.
Key Learning Point
Any child with acute hepatitis who develops altered mental status and coagulopathy should be considered to have acute liver failure until proven otherwise. Hepatic encephalopathy in acute viral hepatitis is a medical emergency requiring intensive monitoring and early referral to a liver transplant center.
