Acute Viral Hepatitis

Acute viral hepatitis is inflammation of the liver caused by infection with one of the five hepatitis viruses; for most people, the inflammation begins suddenly and lasts only a few weeks.

Symptoms

Acute viral hepatitis can produce anything from a minor flu-like illness to fatal liver failure. The severity of symptoms and speed of recovery vary considerably, depending on the particular virus and on the person's response to the infection. Hepatitis A and C often produce very mild symptoms, or none at all, and may go unnoticed, whereas B and E are more likely to produce severe symptoms. Co-infection of hepatitis B with hepatitis D may make the symptoms even more severe.

Symptoms of acute viral hepatitis usually begin suddenly. They include a poor appetite, nausea, vomiting, and often a fever. In people who smoke, a distaste for cigarettes is a typical symptom. Occasionally, especially with hepatitis B infection, an affected person develops joint pains and itchy red hives on the skin (wheals).

After a few days, the urine becomes dark, and jaundice (a yellowish discoloration of the skin and the whites of the eyes) may develop. Both of these symptoms occur because bilirubin (the main pigment in bile, the greenish yellow digestive fluid produced by the liver) builds up in the blood. Most symptoms typically disappear at this point, and the person feels better even though the jaundice gets worse. The jaundice usually peaks in 1 to 2 weeks, then fades over 2 to 4 weeks. Symptoms of cholestasis (a reduction or stoppage of bile flow)--such as pale stools and overall itchiness--may develop.

Rarely, particularly with hepatitis B, symptoms may become extremely severe (fulminant), with liver failure, which may be fatal, especially in adults.

Diagnosis

Doctors suspect acute viral hepatitis on the basis of the person's symptoms. On physical examination, a doctor finds the liver to be tender and somewhat enlarged in about half of the people with acute viral hepatitis. Results of liver function tests indicate that the liver is inflamed and can help doctors distinguish hepatitis due to alcohol abuse from that due to a virus. Usually the specific virus causing the hepatitis or the specific antibodies produced by the body to fight it can be identified as well.

Prevention

Vaccines are available to prevent hepatitis A and B infections. As with most vaccines, however, protection requires allowing a number of weeks for the vaccine to reach its full effect as the person's immune system gradually creates antibodies against the particular virus. People who have not been vaccinated and who are exposed to hepatitis A or B virus can obtain immediate protection with an injection of an antibody preparation called immune globulin. The amount of protection varies, however, and is only temporary. No vaccines are available against hepatitis C, D, or E virus. However, vaccination against hepatitis B virus also eliminates the risk of infection with hepatitis D virus.

A number of other preventive measures against infection with the hepatitis viruses can be taken, such as washing the hands thoroughly before handling food, refraining from high-risk behavior such as sharing needles to inject illicit drugs and having unprotected sex, and avoiding blood transfusions except when absolutely essential.

Treatment and Prognosis

In most people, special treatment is not necessary, although people with unusually severe acute hepatitis may require hospitalization. After the first several days, appetite usually returns and the person does not need to stay in bed. Severe restrictions of diet or activity are unnecessary, and vitamin supplements are not required. Most people can safely return to work after the jaundice clears, even if their liver function test results are not quite normal.

People with hepatitis should avoid alcohol until they fully recover (see Section 10, Chapter 136). A doctor may need to discontinue or reduce the dosage of certain drugs that could build to harmful levels in the body (for example warfarin or theophylline) because of the liver's inability to process (metabolize) them. Thus the person should disclose to the doctor all drugs being taken (both prescription and over-the-counter, including any herbal medicines), so that dosage adjustments can be made if necessary.

A person with acute viral hepatitis usually recovers in 4 to 8 weeks, even without treatment. However, those people infected with hepatitis C and to a lesser extent with hepatitis B may become chronic carriers of the virus. In the carrier state, the person has no symptoms but is still infected, may develop chronic hepatitis even though the disease is not apparent, and is able to transmit the virus to others. A chronic carrier may eventually develop cirrhosis (severe scarring of the liver (see Section 10, Chapter 136)) or liver cancer (see Section 10, Chapter 139).