Acute Viral Hepatitis

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.

Cases range from no symptoms at all to very severe symptoms. People with the infection may have poor appetite, nausea, vomiting, fever, pain in the upper right part of the abdomen and jaundice.

Acute viral hepatitis is common throughout the world. Most cases clear up on their own, but some persist and progress to chronic hepatitis.

Causes

Acute viral hepatitis can be caused by five main hepatitis viruses:

1. Hepatitis A virus.
2. Hepatitis B virus.
3. Hepatitis C virus.
4. Hepatitis D virus.
5. Hepatitis E virus.

Hepatitis A is the most common cause of acute hepatitis, followed by hepatitis B. Other viruses can also cause acute viral hepatitis, including the Epstein–Barr virus (EBV), which causes infectious mononucleosis.

Certain activities increase the risk of hepatitis, such as getting a tattoo or body piercing, sharing needles to inject drugs, using so-called hashish or having multiple sexual partners.

Symptoms

Acute viral hepatitis can cause anything from a mild, flu-like illness to fatal liver failure. Sometimes there are no symptoms at all. The severity of symptoms and speed of recovery vary greatly depending on the virus causing the infection and the person's response to it.

Hepatitis A and C cause very mild symptoms or none at all, and symptoms can appear without anyone noticing. Hepatitis B and E are more likely to cause severe symptoms. Infection with hepatitis B and D at the same time, known as co-infection, can make the symptoms of hepatitis B more severe.

Symptoms of acute viral hepatitis usually begin suddenly and include:

1. Poor appetite.
2. A general feeling of being unwell (malaise).
3. Nausea and vomiting.
4. Fever.
5. Pain in the upper right part of the abdomen, where the liver is located.

An aversion to cigarettes is a typical symptom in smokers. People with the infection, especially hepatitis B, sometimes have joint pain and red, itchy hives.

After three to ten days, the urine sometimes becomes dark and the stools pale. Jaundice may develop, turning the skin and the whites of the eyes yellow, sometimes with 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 haemoglobin, 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 in the whites of the eyes, making them look yellow.

Normally, bilirubin is released into the gut as a component of bile, the yellow-green digestive fluid produced by the liver, and is excreted in the stools, giving them their typical brown colour. In people with hepatitis, stools are pale because bilirubin does not reach the gut to be excreted. Instead it is excreted in the urine, making it dark. The liver may also be enlarged and tender to the touch.

Most of the initial symptoms (loss of appetite, nausea, vomiting and fever) usually disappear within a week, and people feel better even though the jaundice may get worse. Jaundice usually peaks within one to two weeks, then fades over a further two to four weeks. Sometimes, however, it can take much longer for the condition to clear completely.

Fulminant Hepatitis

In rare cases, fulminant hepatitis develops. This is severe hepatitis accompanied by signs of liver failure. It can occur in people with hepatitis A, but is more likely in people with hepatitis B, especially if they also have hepatitis D.

Fulminant hepatitis can progress very quickly, and the liver becomes unable to make enough of the proteins that help the blood clot. However, despite this reduced ability to clot normally, people are not more prone to bruising or bleeding easily or without cause.

The liver cannot remove toxic substances as it normally does, so these build up in the blood and reach the brain, causing hepatic encephalopathy. People's condition may deteriorate, and they can fall into a coma within days to weeks. Fulminant hepatitis can be fatal, especially in adults.

Recovery and Carrying the Virus

People with acute viral hepatitis usually recover within four to eight weeks, even without treatment. However, people with hepatitis C may become carriers of the virus. Adults infected with hepatitis B are less likely to become carriers.

Carriers have no symptoms, even though they remain infected and can pass the virus on to others. Carriers may develop chronic hepatitis even without showing signs of illness, and may eventually develop cirrhosis (severe scarring of the liver) or liver cancer.

Diagnosis

Doctors suspect acute viral hepatitis based on symptoms. During a physical examination, the doctor presses on the abdomen over the liver, which is tender and somewhat enlarged in about 50% of people with acute viral hepatitis.

Doctors suspect fulminant hepatitis when:

1. The person is severely ill and develops jaundice very quickly.
2. Mental function deteriorates rapidly.
3. Blood clotting tests, such as prothrombin time or the international normalised ratio (INR), are abnormal.
4. A person with liver disease starts to get worse quickly.

Investigation of acute viral hepatitis usually begins with blood tests to determine how well the liver is working and whether it is damaged.

Liver Tests

Liver function tests measure the levels of liver enzymes and other substances produced by the liver. These tests can show inflammation of the liver and often help doctors distinguish hepatitis caused by alcohol or drug misuse from hepatitis caused by a viral infection.

To diagnose fulminant hepatitis, doctors carry out liver tests to see how quickly the blood clots, because fulminant hepatitis prevents the blood from clotting normally. If acute viral hepatitis appears likely, it may be possible to identify its cause.

To find out whether the condition has a cause other than a virus, the doctor may ask about medicines the person takes that can cause hepatitis, such as isoniazid, used to treat tuberculosis, and about how much alcohol they drink.

Prevention

Because treatments for viral hepatitis are only partly effective, preventing viral hepatitis is extremely important.

Preventive Measures

Preventive measures against hepatitis virus infection include:

1. Washing hands thoroughly before handling food.
2. Not sharing needles to inject drugs.
3. Not sharing toothbrushes, razors or other items that could come into contact with blood.

Supportive Care

Most people with acute viral hepatitis do not need specific treatment. However, people with severe acute hepatitis may need their mental state monitored. People with hepatitis are advised not to drink alcohol.

An infected liver may not process medicines normally. The doctor may need to stop or reduce the dose of medicines that could build up to harmful levels in the body, such as warfarin or theophylline.

People with hepatitis should therefore tell their doctor about all the medicines they take, whether prescription or over-the-counter, including herbal remedies, so that doses can be adjusted if necessary.