Hepatitis

The liver is an abdominal organ that is responsible for an array of vital functions. Hepatitis is a general term used to refer to inflammation of the liver, which can be acute or chronic with a wide variety of causes. Understanding the severity of hepatitis requires an appreciation for the normal synthetic and metabolic functions of the liver.

The liver synthesizes proteins, carbohydrates, and fats. The major site for production of proteins for blood clotting is the liver. In addition, maintenance of sugar balance requires liver function. Liver cells create glucose from pyruvate and lactate in the blood, and can use blood sugars to generate amino acids, fatty acids, or can store excess glucose in the form of glycogen. The liver also regulates production of fatty acids and cholesterol, and produces bile that is important in the metabolism of fats. Last, detoxification of a large number of drugs is accomplished by liver cells, as is the removal of ammonia from the blood.

Acute viral hepatitis is a general term used to describe the liver inflammation caused by at least five different, unrelated viruses. The five known hepatitis viruses are hepatitis A, B, C, D (or delta), and

E. Hepatitis A and E are spread through a fecal-oral route secondary to poor sanitary conditions. They are highly contagious and can occur in outbreaks but do not have long-term health consequences. Hepatitis B, C, and D are spread via infected blood and sexual contact. While hepatitis B, C, and D do not cause outbreaks, they can lead to chronic hepatitis, which causes cirrhosis and liver cancer (hepatocellular carcinoma).

Symptoms of acute hepatitis are varied. There are prodromal symptoms that often precede acute hepatitis, such as a skin rash, painful swollen joints, and fever. Acute hepatitis produces symptoms such as anorexia and nausea. One of the most noticeable signs of hepatitis is jaundice, or yellowing of the skin. The normal liver eliminates a compound caused bilirubin, but hepatic dysfunction leads to a backup of bilirubin into the circulation, and accumulation of this yellow compound in the skin, conjunctiva and mucous membranes. In the cases of hepatitis A and C, these symptoms resolve; however, with hepatitis B, C, and D, there is often progression to chronic liver disease.

Chronic hepatitis can be caused by viral illness and also by medications, alcohol, metabolic abnormalities, and autoimmune disorders. Medications that may potentially cause drug-induced liver disease include isoniazid, nonsteroidal antiinflammatory medications, methyldopa, nitrofurantoin, and many others. Indications of chronic hepatitis are vague, and include fatigue, sleep disorders, pain under the right rib cage, and enlarge liver and spleen, redness (erythema) of the palms and spider angiomata, or dilated blood vessels visible on the skin. Chronic hepatitis can eventually lead to cirrhosis of the liver, or a state of scarring [Page 829]and fibrosis. Patients are often fatigued and susceptible to infection, and may lose weight and become malnourished due to malabsorption. Poor absorption of vitamin A and D lead to vision impairment and osteopenia (thinning of bones), respectively. In addition, liver cirrhosis can lead to gynecomastia (swelling of breast tissue) and atrophic testicles.

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