Overview of Acute Viral Hepatitis

Acute viral hepatitis can be caused by five major hepatitis viruses (see table The Hepatitis Viruses The Hepatitis Viruses ):

The hepatitis A virus is the most common cause of acute hepatitis, followed by the hepatitis B virus.

Other viruses can also cause acute viral hepatitis. These viruses include the Epstein-Barr virus (EBV), which is the virus that causes infectious mononucleosis Infectious Mononucleosis Epstein-Barr virus causes a number of diseases, including infectious mononucleosis. The virus is spread through kissing. Symptoms vary, but the most common are extreme fatigue, fever, sore throat... read more (mono).

Engaging in certain activities, such as getting a tattoo or body piercing, sharing needles to inject drugs, or having multiple sex partners, increases the risk of developing hepatitis.

Acute viral hepatitis can cause anything from a minor flu-like illness to fatal liver failure Liver Failure Liver failure is severe deterioration in liver function. Liver failure is caused by a disorder or substance that damages the liver. Most people have jaundice (yellow skin and eyes), feel tired... read more . Sometimes there are no symptoms. 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 cause very mild symptoms or none at all and may be unnoticed. Hepatitis B and E are more likely to produce severe symptoms. Infection with both hepatitis B and D (called coinfection) may make the symptoms of hepatitis B even more severe.

Symptoms of acute viral hepatitis usually begin suddenly. They include

In people who smoke, a distaste for cigarettes is a typical symptom. Occasionally, especially with hepatitis B, infected people develop joint pains and itchy red hives on the skin (wheals or urticaria Hives Hives are red, itchy, slightly elevated swellings. The swelling is caused by the release of chemicals (such as histamine) from mast cells in the skin, which cause fluid to leak out of small... read more ).

Appetite usually returns about a week after symptoms begin.

Sometimes, after 3 to 10 days, the urine becomes dark, and stool becomes pale. Jaundice Jaundice in Adults In jaundice, the skin and whites of the eyes look yellow. Jaundice occurs when there is too much bilirubin (a yellow pigment) in the blood—a condition called hyperbilirubinemia. (See also Overview... read more (a yellowish discoloration of the skin and whites of the eyes) may develop. It is sometimes accompanied by itching. These symptoms occur because the damaged liver cannot remove bilirubin from the blood as it normally does. Bilirubin is a yellow pigment produced when hemoglobin (the part of red blood cells that carries oxygen) is broken down as part of the normal process of recycling old or damaged red blood cells. Bilirubin then builds up in the blood and is deposited in the skin (making it look yellow and causing itching) and the whites of the eyes (making them look yellow). Bilirubin is normally secreted into the intestine as a component of bile (the greenish-yellow digestive fluid produced by the liver) and excreted in stool, giving stool its typical brown color. In people with hepatitis, stools are pale because bilirubin does not enter the intestine to be eliminated in stool. Instead bilirubin is eliminated in urine, making the urine dark.

The liver may be enlarged and tender.

Most of the initial symptoms (poor appetite, nausea, vomiting, and fever) usually disappear within a week, and people feel better even though the jaundice may worsen. The jaundice usually peaks in 1 to 2 weeks, then fades over 2 to 4 weeks. But it can sometimes take much longer to resolve completely.

Rarely, fulminant hepatitis develops. Fulminant hepatitis is severe hepatitis with signs of liver failure Liver Failure Liver failure is severe deterioration in liver function. Liver failure is caused by a disorder or substance that damages the liver. Most people have jaundice (yellow skin and eyes), feel tired... read more . Fulminant hepatitis can occur in people with hepatitis A, but it is more likely to develop in people with hepatitis B, particularly if they also have hepatitis D. It can also occur in people taking drugs that can damage the liver Liver Injury Caused by Drugs Many drugs can affect the way the liver functions, damage the liver, or do both. (See also Drugs and the Liver.) Some drugs, such as statins (used to treat high cholesterol), can increase the... read more (including herbal supplements), such as acetaminophen, or be caused by alcoholic hepatitis in people with a long history of heavy drinking Alcohol-Related Liver Disease Alcohol-related liver disease is liver damage caused by drinking too much alcohol for a long time. In general, the amount of alcohol consumed (how much, how often, and for how long) determines... read more . Fulminant hepatitis can progress very quickly, usually within days or weeks. The liver can no longer synthesize enough of the proteins that help blood clot. However, even though blood does not clot normally, people are not more likely to bruise or to bleed easily or without cause. The liver cannot remove toxic substances as it normally does. So these toxic substances build up in the blood and reach the brain, causing mental function to deteriorate quickly—called hepatic (portosystemic) encephalopathy Hepatic Encephalopathy Hepatic encephalopathy is deterioration of brain function that occurs in people with severe liver disease because toxic substances normally removed by the liver build up in the blood and reach... read more . People may lapse into a coma within days to weeks. Fulminant hepatitis may be fatal, especially in adults. Sometimes liver transplantation Liver Transplantation Liver transplantation is the surgical removal of a healthy liver or sometimes a part of a liver from a living person and then its transfer into a person whose liver no longer functions. (See... read more must be done immediately to save the person's life.

People with acute viral hepatitis usually recover in 4 to 8 weeks, even without treatment. However, some people infected with hepatitis B or C develop chronic infections.

Doctors suspect acute viral hepatitis based on symptoms. During the physical examination, a doctor presses on the abdomen above the liver, which is tender and somewhat enlarged in about half of the people with acute viral hepatitis.

Doctors suspect fulminant hepatitis if

Testing for acute viral hepatitis usually begins with blood tests to determine how well the liver is functioning and whether it is damaged (liver tests Liver Blood Tests Liver tests are blood tests that represent a noninvasive way to screen for the presence of liver disease (for example, viral hepatitis in donated blood) and to measure the severity and progress... read more ). Liver tests involve measuring the levels of liver enzymes and other substances produced by the liver. These tests can indicate whether the liver is inflamed and often help doctors distinguish hepatitis due to alcohol abuse from that due to a virus.

To diagnosis fulminant hepatitis, doctors do liver tests to determine how quickly blood clots (because if people have fulminant hepatitis, blood does not clot normally).

If acute viral hepatitis seems likely, the cause is identified if possible. To help identify the cause, doctors usually do the following:

These blood tests can detect parts of specific viruses or specific antibodies produced by the body to fight the viruses. (​ Antibodies Antibodies One of the body's lines of defense ( immune system) involves white blood cells (leukocytes) that travel through the bloodstream and into tissues, searching for and attacking microorganisms and... read more ​ are proteins produced by the immune system to help defend the body against attack by viruses and other foreign invaders.)

To determine whether the cause may be something other than a virus, the doctor may ask whether people take any drugs that can cause hepatitis (such as isoniazid, used to treat tuberculosis) and how much alcohol they drink.

Occasionally, if the diagnosis is unclear, a liver biopsy Biopsy of the Liver Doctors can obtain a sample of liver tissue during exploratory surgery, but more often they obtain a sample by inserting a hollow needle through the person's skin and into the liver. This type... read more is done: A sample of liver tissue is removed with a needle and examined.

Because treatments for viral hepatitis are only partially effective, preventing viral hepatitis is very important.

For most people with acute viral hepatitis, special treatment is not necessary. However, people with severe acute hepatitis may require hospitalization so that symptoms can be treated. If doctors suspect that fulminant hepatitis is developing, the person is hospitalized so that mental status can be monitored, liver tests can be done, and doctors can determine whether liver transplantation is needed.

After the first several days, appetite usually returns and people do 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 test results are not quite normal.

People with hepatitis should not drink alcohol until they have fully recovered.

The infected liver may not process (metabolize) drugs normally. So a doctor may need to stop a drug or reduce the dosage of a drug that could accumulate to harmful levels in the body (such as warfarin or theophylline). Thus, people with hepatitis should tell their doctor all the drugs they are taking (both prescription and nonprescription, including any medicinal herbs), so that the dosage of the drug can be adjusted if necessary.

If itching occurs, cholestyramine, taken by mouth, is often effective.

If hepatitis B causes fulminant hepatitis, people are usually treated in an intensive care unit. Antiviral drugs may help. However, liver transplantation Liver Transplantation Liver transplantation is the surgical removal of a healthy liver or sometimes a part of a liver from a living person and then its transfer into a person whose liver no longer functions. (See... read more is the most effective treatment and is the best hope of survival, particularly for adults.

People with acute hepatitis C infection should be treated with antiviral drugs to decrease the risk of transmission of the infection to others and to decrease the risk of hepatitis becoming chronic.