Chronic hepatitis C virus infection associated with dermatomyositis and hepatocellular carcinoma.

Dermatomyositis is a rare and idiopathic inflammatory myopathy with characteristic cutaneous manifestations. In recent years, some researchers have showed the cause of dermatomyositis might be due to an autoimmune response induced by viral infections. However, chronic hepatitis C virus (HCV) infection associated with dermatomyositis is very rare. In this report, we present a patient with dematomyositis with abnormal liver function test results and elevated alfa-fetoprotein level. After excluding multiple viral infections known to cause myositis, the case was proven to be chronic hepatitis C by positive HCV-RNA in the serum. Abdominal computed tomography showed a liver tumor on the right lobe and needle biopsy proved it to be hepatocellular carcinoma. Chronic hepatitis C or hepatocellular carcinoma might cause dermatomyositis by inducing the formation of autoantibodies. Chronic hepatitis C or hepatocellular carcinoma should be considered in patients of dermatomyositis if no other cause is found.