Causes of Acute Hepatic Failure/Hepatitis in Childhood
The causes of acute hepatic failure and hepatitis in children differ substantially from adults and vary by age group, with viral hepatitis, drug-induced liver injury, metabolic/genetic disorders, and immune-mediated diseases being the primary etiologies, though indeterminate causes constitute a considerable proportion of cases in Western countries.
Age-Specific Etiological Patterns
Neonates and Infants
- Neonatal hemochromatosis - the leading cause of liver failure in neonates, presenting within the first few days of life 1
- Metabolic disorders: α-1-antitrypsin deficiency (most common inherited cause requiring transplantation in children), tyrosinemia, glycogen storage diseases 1
- Biliary atresia - universally fatal if untreated and the single most common cause of liver disease leading to transplantation in children 2
- Bile acid synthesis disorders - present as neonatal cholestasis with hallmark features of normal/low serum bile acids, normal GGT, and absence of pruritus 2
Older Children and Adolescents
- Viral hepatitis: Hepatitis A (most common, 34-48% of cases), Hepatitis E (12-22%), Hepatitis B 3, 4
- Note: Hepatitis C alone does not appear to cause acute liver failure 5
- Wilson disease - autosomal recessive copper excretion disorder causing acute or chronic hepatitis; fulminant presentation requires urgent transplantation 1
- Drug-induced liver injury - including acetaminophen toxicity and idiosyncratic reactions 6, 7
- Autoimmune hepatitis - can present with acute decompensation 8
- Infectious causes: Dengue (22.5%), malaria, enteric fever, herpes virus (especially in immunosuppressed or pregnant patients) 5, 3
Critical Metabolic Disorders Requiring Recognition
Progressive familial intrahepatic cholestasis (PFIC) types 1,2, and 3 - present with progressive cholestasis in infancy, can severely impact quality of life despite preserved liver function 2
Alagille syndrome - multisystem disorder affecting liver, heart, eyes, skeleton, kidneys, and vasculature; requires cardiac assessment before transplantation 1, 2
Hereditary tyrosinemia type 1 - presents with systemic illness and liver dysfunction in infants; cirrhosis and hepatocellular carcinoma common at diagnosis 1
Indeterminate Causes
A substantial proportion (28-33%) of pediatric acute liver failure cases remain indeterminate despite thorough evaluation 6, 4. This is a unique feature distinguishing pediatric from adult acute liver failure.
Key Diagnostic Considerations
Critical Pitfalls to Avoid
- Absence of icterus does not rule out hepatitis - only 70% sensitivity for diagnosis 3
- Hepatic encephalopathy may be a late event or may not develop at all in children with acute liver failure, particularly in infants - unlike adults where it's a defining feature 7
- Fever is the most common presenting complaint (90%), not jaundice 3
Essential Laboratory Evaluation
- Viral serologies: HAV IgM/IgG, HBsAg, anti-HBc IgM, HEV (especially with travel history to endemic areas) 5
- Metabolic screening: α-1-antitrypsin phenotype, ceruloplasmin (though can be falsely elevated with inflammation or depressed with severe liver disease of any cause), serum amino acids 1
- Bile acid analysis: Fast atom bombardment-mass spectrometry (FAB-MS) and gas chromatography-mass spectrometry (GC-MS) for bile acid synthesis disorders 2
- INR uncorrected by vitamin K - reflects severity of liver synthetic dysfunction 8
- Creatine kinase - helps differentiate muscle from liver disease with raised transaminases 8
Imaging
Doppler ultrasound of hepatic vasculature is essential when assessing hepatomegaly/splenomegaly to differentiate extrahepatic portal hypertension from intrinsic liver disease 8
Urgent Referral Criteria
Immediate contact with a pediatric liver transplant center should be initiated for: 2
- Children with acute liver failure or acute decompensation of established liver disease
- Liver-based metabolic crises refractory to medical/surgical therapy
- Biliary atresia patients with total bilirubin >6 mg/dL beyond 3 months post-hepatoportoenterostomy
- Unresectable hepatoblastoma or hepatocellular carcinoma
Geographic and Developmental Variations
The etiology varies significantly by geographic region and level of development. In resource-limited settings like Bangladesh, viral hepatitis (34%) and Wilson disease are more common causes, while in Western countries, indeterminate causes predominate 6, 4.