Acute viral hepatitis

1. Big picture

Acute viral hepatitis is an acute inflammatory liver injury caused by hepatotropic viruses, classically HAV, HBV, HCV, HDV, and HEV. For the exam, the key is not to memorize everything equally, but to answer three questions quickly:

1. Is this hepatocellular jaundice? High alanine aminotransferase/aspartate aminotransferase (ALT/AST), malaise, anorexia, nausea, dark urine, jaundice.

2. Which virus is likely? Fecal–oral exposure suggests HAV/HEV; blood/sex/perinatal exposure suggests HBV/HCV/HDV.

3. Is there acute liver failure? International normalized ratio (INR) ≥ 1.5 + hepatic encephalopathy in a patient without known cirrhosis = emergency transplant-center referral.

The core exam pattern is:

Prodrome: fever, malaise, anorexia, nausea, right upper quadrant discomfort
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Icteric phase: dark urine, pale stool, jaundice, pruritus
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Recovery OR progression to fulminant hepatitis/chronic hepatitis

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