Hepatitis C: a review and update

The hepatitis C virus is an RNA virus that is a major cause of acute and ch ronic hepatitis. It is contracted chiefly through parenteral exposure to in fected material such as blood transfusions or injections with dirty needles . Those at highest risk for development of hepatitis C are injection-drug u sers, people who snort cocaine with shared straws, and health care workers who are at risk for needle-stick and other exposures. Although the incidenc e of acute hepatitis C infection has fallen dramatically in the United Stat es during the past decade, the prevalence of infection remains high (approx imately 2.7 million Americans) because chronic hepatitis C develops ill abo ut 75% of those infected. Both acute and chronic hepatitis C are asymptomat ic in most patients. However, chronic hepatitis C is a slowly progressive d isease and results in severe morbidity in 20% to 30% of infected persons. C hronic hepatitis C is associated with host of extrahepatic manifestations, many of which may be seen by dermatologists. The most frequent of these are mixed cryoglobulinemia with leukocytoclastic vasculitis and porphyria cuta nea tarda.