Hepatitis

Hepatitis (plural hepatitides) implies injury to liver characterised 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[1]). 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, anti tuberculosis 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

Signs and symptoms
Acute Hepatitis

Clinically, the course of acute hepatitis varies widely from mild symptoms requiring no treatment to fulminant hepatic failure needing liver transplantation. Acute viral hepatitis are more likely to be asymptomatic in younger people. Symptomatic individuals may present after convalescent stage of 7 to 10 days, with the total illness lasting 2 to 6 weeks.[4]

Initial features are of nonspecific flu-like symptoms, common to almost all acute viral infections and may include malaise, muscle and joint aches, fever, nausea or vomiting, diarrhea, and headache. More specific symptoms, which can be present in acute hepatitis from any cause are: profound loss of appetite, aversion to smoking among smokers, dark urine, yellowing of the eyes and skin (i.e. jaundice) and abdominal discomfort. Physical findings are usually minimal, apart from jaundice (33%) and tender hepatomegaly (10%). There can be occasional lymphadenopathy (5%) or splenomegaly (5%).[5]

Chronic Hepatitis

Majority of patients will remain asymptomatic or mildly symptomatic, abnormal blood tests being the only manifestation. Features may be related to extent of liver damage or the cause of hepatitis. Many experience return of symptoms related to acute hepatitis. Jaundice can be a late feature and may indicate extensive damage. Other features include abdominal fullness from enlarged liver or spleen, low grade fever and fluid retention (ascites). Extensive damage and scarring of liver i.e. cirrhosis leads to weight loss, easy bruising and bleeding tendencies. Acne, abnormal menstruation, lung scarring, inflammation of the thyroid gland and kidneys may be present in women with autoimmune hepatitis.[6]

Findings on clinical examination are usually those of cirrhosis or are related to aetiology.