Makindo Medical Notes

Related Subjects: |Chronic liver disease |Liver Function Tests |Ascites Assessment and Management |Budd-Chiari syndrome |Alcoholism and Alcoholic Liver Disease |Liver Transplantation

Fulminant liver failure occurs in about 1 in 1000 cases of Hepatitis A, with higher risk in the elderly and those with pre-existing chronic liver disease (especially HBV/HCV).

About

• 🦠 Hepatitis A is a picornavirus, an RNA virus transmitted mainly by the faeco-oral route.
• Does not cause chronic disease – unlike HBV or HCV.
• Incubation 2–6 weeks (mean ~30 days).
• Acute liver failure: rare but important complication.
• More severe in patients with underlying liver disease or immunosuppression.

Epidemiology

• 🍤 Spread via contaminated food and water – classically undercooked shellfish.
• Virus shed in stool before and after symptoms → high infectivity.
• Transient viraemia can allow transmission via blood (rare).
• Sexual transmission possible, especially among men who have sex with men (MSM).
• Still endemic in many low- and middle-income countries; sporadic outbreaks occur in the UK.

Pathophysiology

• Replicates in hepatocytes and Kupffer cells.
• Immune-mediated damage: cytotoxic CD8 T cells and NK cells attack infected hepatocytes.
• Histology: lobular hepatitis with zone 3 necrosis and bile duct proliferation.

Clinical Presentation

• 🟡 Jaundice, fever, malaise, anorexia, and nausea.
• Tender hepatomegaly is typical; splenomegaly in ~20%.
• Children often asymptomatic; adults more likely to present with jaundice.
• Other features: aversion to cigarettes (classic exam clue), abdominal pain, dark urine, pale stools.
• Rare complications: optic neuritis, transverse myelitis, aplastic anaemia, thrombocytopenia, arthritis, vasculitis.
• Consider admission if dehydration, persistent vomiting, coagulopathy, or encephalopathy.

Investigations

• IgM anti-HAV: confirms acute infection (appears at onset of illness, persists ~6 months).
• IgG anti-HAV: indicates past infection or vaccination (lifelong immunity).
• 📈 Marked rise in ALT/AST (often >1000 IU/L); bilirubin raised; ALP usually normal/mildly raised.
• Coagulation screen (check INR) if concern about hepatic dysfunction.

Management

• 🛌 Supportive only: rest, hydration, avoid alcohol and hepatotoxic drugs (e.g., paracetamol).
• Hospital admission if fulminant hepatitis or severe dehydration/vomiting.
• Vaccination: Recommended for travellers to endemic areas, MSM, and those with chronic liver disease.
• Post-exposure prophylaxis: Intramuscular immune globulin within 14 days reduces risk of infection.
• Isolation and good hygiene reduce community spread.