Hepatitis B is also known as serum hepatitis and is spread through blood and sexual contact. It is seen with increased frequency among intravenous drug users who share needles and among the homosexual population. This photograph is an electronmicroscopic image of hepatitis B virus particles. (Image courtesy of the Centers for Disease Control and Prevention.)

The esophagus, stomach, large and small intestine, aided by the liver, gallbladder and pancreas convert the nutritive components of food into energy and break down the non-nutritive components into waste to be excreted.

Chronic active hepatitis is a liver disease caused by infection, drug ingestion, metabolic or autoimmune disorders. Necrosis (death) of liver cells, inflammation and fibrosis may lead to liver failure. Death within 5 years of onset occurs in 40 to 50% of patients.

Gianotti-Crosti disease is also called acrodermatitis of childhood. These red, elevated lesions do not contain pus and can occur on the limbs, buttocks, face, and neck.

The hepatitis B vaccine is recommended for healthcare workers, people who live with someone with hepatitis B, and others at higher risk. The hepatitis B virus can damage liver cells. Immunization is also recommended for all infants and unvaccinated adolescents.