Atypical clinical manifestations of hepatitis A.

Viral A hepatitis is a self-limited infection occurring predominantly among children usually as an anicteric often subclinical illness. Adults afflicted with this virus are more likely to develop icteric hepatitis. This is exemplified in developed countries when a common source outbreak occurs among non-immune adults. Fulminant hepatitis is uncommon in the USA and hepatitis A has never been documented to evolve into chronic hepatitis. However, prolonged cholestasis and relapsing hepatitis are well described. The usual features of cholestatic viral hepatitis A are pruritus, fever, diarrhoea, and weight loss. Serum bilirubin levels are > 10 mg/dl and the clinical course lasts at least 12 weeks. Cholestasis will spontaneously resolve, although corticosteroids will hasten the resolution but may predispose the patient to develop a relapse of the hepatitis. A biphasic or relapsing form of viral hepatitis A occurs in 6 to 10% of cases. The initial episode lasts 3 to 5 weeks and is followed by a period of remission characterized by normal liver chemistries lasting 4 to 5 weeks. Relapse may mimic the initial episode of the acute hepatitis. The full duration of the illness ranges from 16 to 40 weeks from the onset and immunoglobulin M antibody to hepatitis A virus persists throughout the clinical course. Hepatitis A virus has been recovered from stools during the relapse. Extrahepatic manifestations of hepatitis A include evanescent skin rash and transient arthralgias. Documented cases of arthritis and cutaneous vasculitis have been associated with cryoglobulinaemia and are rare.