Saturday, May 3, 2008

Hepatitis

Hepatitis
(plural hepatitides) implies injury to liver characterized by presence of inflammatory cells in the liver tissue. Etymologically from ancient Greek hepar (ηπαρ) or hepato- (ηπατο-), meaning 'liver,' and suffix -itis, denoting 'inflammation' (c. 1727). The condition can be self limiting, healing on its own, or can progress to scarring of the liver. Hepatitis is acute when it lasts less than 6 months and chronic when it persists longer. A group of viruses known as the hepatitis viruses cause most cases of liver damage worldwide. Hepatitis can also be due to toxins (notably alcohol), other infections or from autoimmune process. It may run a subclinical course when the affected person may not feel ill. The patient becomes unwell and symptomatic when the disease impairs liver functions that include, among other things, screening of harmful substances, regulation of blood composition, and production of bile to help digestion.

Causes

Acute hepatitis
* Viral Hepatitis: Hepatitis A to E (more than 95% of viral cause), Herpes simplex, Cytomegalovirus, Epstein-Barr, yellow fever virus, adenoviruses.
* Non viral infection: toxoplasma, Leptospira, Q fever,[2] rocky mountain spotted fever[3]
* Alcohol
* Toxins: Amanita toxin in mushrooms, carbon tetrachloride, asafetida
* Drugs: Paracetamol, amoxycillin, antituberculosis medicines, minocycline and many others (see longer list below).
* Ischemic hepatitis (circulatory insufficiency)
* Pregnancy
* Auto immune conditions, e.g. Systemic Lupus Erythematosus (SLE)
* Metabolic diseases, e.g. Wilson's disease

Chronic hepatitis
* Viral hepatitis: Hepatitis B with or without hepatitis D, hepatitis C (Hepatitis A and E do not lead to chronic disease)
* Autoimmune: Autoimmune hepatitis
* Alcohol
* Drugs: methyl-dopa, nitrofurantoin, isoniazide, ketoconazole
* Non-alcoholic steatohepatitis
* Heredity: Wilson's disease, alpha 1-antitrypsin deficiency
* Primary biliary cirrhosis and primary sclerosing cholangitis occasionally mimic chronic hepatitis

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