Hepatitis C-associated cryoglobulinemia.

Leukocytoclastic vasculitis can be caused by a variety of infectious, neoplastic, and autoimmune processes. Cryoglobulinemia should be included in this differential diagnosis. Recently, many patients with "idiopathic" cryoglobulinemia have been found to have hepatitis C. We report the clinical and histopathologic features of a patient who presented with leukocytoclastic vasculitis and was found, after further investigation, to have cryoglobulinemia as well. This led to the identification of a previously undiagnosed hepatitis C infection. Dermatologists should be aware of this association because identification and treatment of hepatitis C in patients with cryoglobulinemia appears to have dramatic effect on prognosis.