Fulminant hepatitis is the most feared complication of viral hepatitis: acute liver failure with massive hepatocyte necrosis. It occurs mostly with HBV, HDV and HEV, and up to 50% of all cases of fulminant hepatitis are due to HBV infection. HCV almost never causes it. HEV usually does not either, but it can occur in about 1% of HEV cases, and the risk is far higher in pregnancy, where it affects up to 20% of pregnant women. HAV causes fulminant hepatitis only rarely — in older adults with underlying chronic liver disease such as chronic HBV or HCV, and mostly in elderly or immunosuppressed patients.
Fulminant hepatitis is recognised by a characteristic set of findings:
- hepatic encephalopathy, which mostly progresses to coma
- an extensively small and shrunken liver, with lowered ALT and AST and a rapidly rising bilirubin
- an extensively prolonged prothrombin time (PT)
- ascites and oedema
Its terminal events are brainstem compression, gastrointestinal bleeding, sepsis, cardiovascular collapse and renal failure, and its mortality is as high as 80%.
Rarer complications of viral hepatitis include pancreatitis, myocarditis, aplastic anaemia, atypical pneumonia and peripheral neuropathy.