Topic Resources
Acute viral hepatitis is
inflammation of the liver caused by infection with one of the five
hepatitis viruses. In most people, the inflammation begins suddenly and
lasts only a few weeks.
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Symptoms range from none to very severe.
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Affected people may have a poor appetite, nausea, vomiting, fever, pain in the upper right part of the abdomen, and jaundice.
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Doctors do blood tests to diagnose hepatitis and identify its cause.
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Vaccines can prevent hepatitis A, B, and E (the hepatitis E vaccine is available only in China).
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Usually, specific treatment is not needed.
Acute viral hepatitis is common throughout the world. Most cases
of acute viral hepatitis resolve on their own, but some persist and
progress to chronic hepatitis.
Causes
Acute viral hepatitis can be caused by five major hepatitis viruses (see table 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 Ebstein-Barr virus (EBV), which is the virus that causes infectious mononucleosis (mono).
Engaging in certain activities, such as getting a tattoo or body
piercing, sharing needles to inject drugs, or having several sex
partners, increases the risk of developing hepatitis.
Overview of Viral Hepatitis
VIDEO
Symptoms
Acute viral hepatitis can cause anything from a minor flu-like illness to fatal liver failure.
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
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A poor appetite
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A general feeling of illness (malaise)
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Nausea and vomiting
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Fever
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Pain in the upper right part of the abdomen (where the liver is located)
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).
Appetite usually returns about a week after symptoms begin.
Sometimes, after 3 to 10 days, the urine becomes dark, and stool becomes pale. Jaundice
(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.
Fulminant hepatitis can occur in people with hepatitis A but is more
likely to develop in people with hepatitis B, particularly if they also
have hepatitis D. Fulminant hepatitis can progress very quickly. 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 hepatic (portosystemic) encephalopathy.
People may lapse into a coma within days to weeks. Fulminant hepatitis may be fatal, especially in adults. Sometimes liver transplantation must be done immediately to save the person's life.
People may lapse into a coma within days to weeks. Fulminant hepatitis may be fatal, especially in adults. Sometimes liver transplantation 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, people infected with hepatitis C
may become carriers of the virus. Adults infected with hepatitis B are
less likely to become carriers. Carriers have no symptoms but are still
infected and can transmit the virus to others. Carriers may develop chronic hepatitis even though the disease is not apparent. Carriers may eventually develop cirrhosis (severe scarring of the liver) or liver cancer.
Diagnosis
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Blood tests
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
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People are very ill and develop jaundice very quickly.
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Mental function quickly deteriorates.
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Blood tests to determine how quickly blood clots—prothrombin time or international normalized ratio (INR)—are abnormal.
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People who have liver disease start worsening rapidly.
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 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:
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Ask about activities that can increase the risk of getting viral hepatitis (see table The Hepatitis Viruses).
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Do blood tests to help them identify which hepatitis virus is causing the infection.
These blood tests can detect parts of specific viruses or specific antibodies produced by the body to fight the viruses. (Antibodies 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 is
done: A sample of liver tissue is removed with a needle and examined.
Prevention
Because treatments for viral hepatitis are only partially effective, preventing viral hepatitis is very important.
Vaccines
Vaccines to prevent hepatitis A and hepatitis B are available in
the United States. A vaccine for hepatitis E is currently available only
in China. No vaccines against hepatitis C or D virus are available.
However, vaccination against hepatitis B virus also reduces the risk of
infection with hepatitis D virus. Hepatitis vaccines are given by
injection into muscle.
Routine vaccination with the hepatitis A vaccine and hepatitis B vaccine is recommended in the United States for all children (see figure Vaccinating Infants and Children) and for adults at high risk of getting hepatitis (see table The Hepatitis Viruses).
As with most vaccines, protection requires allowing a number of
weeks for the vaccine to reach its full effect as the immune system
gradually creates antibodies against the particular virus.
If people who have not been vaccinated are exposed to hepatitis A
virus, they are given a single dose of hepatitis A vaccine or an
injection of standard immune globulin, depending on their age and health. Standard immune globulin contains antibodies obtained from blood collected from a large group of people who have a normal immune system. Immune globulin
prevents infection or decreases its severity. However, the amount of
protection it provides varies, and the protection is only temporary.
If people who have not been vaccinated are exposed to hepatitis B virus, they are given hepatitis B immune globulin and are vaccinated. Hepatitis B immune globulin
contains antibodies obtained from the blood of people who have high
levels of antibodies to hepatitis B. It is given by injection into a
muscle or into a vein. This preparation helps the body fight the
infection and prevents symptoms or decreases their severity, although it
is unlikely to prevent infection.
Babies born to mothers with hepatitis B are given hepatitis B immune globulin (injected into a muscle) and hepatitis B vaccine.
Other preventive measures
Other preventive measures against infection with the hepatitis viruses can be taken:
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Washing hands thoroughly before handling food
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Not sharing needles to inject drugs
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Not sharing toothbrushes, razors, or other items that could get blood on them
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Practicing safe sex—for example, using barrier protection such as a condom
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Limiting the number of sex partners
Donated blood is unlikely to be contaminated because it is screened. Nonetheless, doctors help reduce the risk of hepatitis by ordering blood transfusions only when essential. Before surgery, people can also sometimes prevent the need for transfusion of blood from an unknown donor by donating their own blood weeks before the operation.
Treatment
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Supportive care
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 is the most effective treatment and is the best hope of survival, particularly for adults.
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