You must add a |reason= parameter to this Cleanup template – replace it with {{Cleanup|reason=<Fill reason here>}}, or remove the Cleanup template.
In medicine (gastroenterology), hepatitis is any disease featuring inflammation of the liver. The clinical signs and prognosis, as well as the therapy, depend on the cause.
Signs and symptoms
Hepatitis is characterised by abdominal pain, fever, hepatomegaly (enlarged liver) and jaundice (icterus). Some chronic forms of hepatitis show very few of these signs and only present when the longstanding inflammation has led to the replacement of liver cells by connective tissue; the result is cirrhosis.
Causes
Viral
Most hepatitis cases due to viral infections:
- Hepatitis A
- Hepatitis B
- Hepatitis C
- D-agent (requires presence of the hepatitis B virus)
- Hepatitis E
- Please see the respective articles for more detailed information
Hepatitis A is an enterovirus transmitted by the orofecal route, such as contaminated food. It causes an acute form of hepatitis and does not have a chronic stage.
Hepatitis B causes both acute and chronic hepatitis. It is transmitted by blood (blood transfusion, now rare) or sexually. Blood contact can occur by sharing syringes in intravenous drug use, prompting needle-exchange programmes in many countries as a form of prevention. Hepatitis B is endemic in a number of (mainly South-East Asian) countries, making cirrhosis and hepatocellular carcinoma big killers.
Hepatitis C is probably not transmitted sexually but only by blood contact. It leads to a chronic form of hepatitis, culminating in cirrhosis. It can remain asymptomatic for 10-20 years.
Two other hepatitisviruses are known, hepatitis D and E. The D agent cannot proliferate without the presence of hepatitis B virus, because its genome lacks certain essential genes. Hepatitis E produces a picture quite similar to hepatitis A, although it can take a fulminant course in pregnant women.
Another kind of hepatitis, hepatitis G, has also been identified.
Other viruses can cause infectious hepatitis:
Toxic
Ethanol, mostly in alcoholic beverages, is an important cause of hepatitis. Although in alcoholics it is generally quite mild, it can exacerbate after a drinking spree. It is one of main causes of cirrhosis in Western countries.
Tetrachloromethane ("tetra") and chloroform, both chlorine-containing carbohydrates, cause steatohepatitis (hepatitis with fatty liver). A large number of drugs can cause hepatitis, including the very commonly used statins. The anti-diabetic drug troglitazone was withdrawn in 2000 for causing hepatitis.
Cholestatic
Longstanding obstruction of the bile duct (by gallstones or external obstruction by cancer) leads to destruction and inflammation of liver tissue.
Autoimmune
Anomalous presentation of human leukocyte antigen (HLA) class II on the surface of hepatocytes — possibly due to genetic predisposition or acute liver infection — causes a cell-mediated immune response against the body's own liver, resulting in autoimmune hepatitis.
Some autoimmune disorders affect the liver, including a form of primary autoimmune hepatitis.
In severe cases of alpha 1-antitrypsin deficiency (A1AD), the acculumated protein causes in the endoplasmic reticulum causes liver cell damage and inflammation. This is technically not an autoimmune disease.