Hepatitis C virus and its cutaneous manifestations: treatment in the direct-acting antiviral era.

New all-oral direct-acting antivirals (DAA) have changed the hepatitis C virus (HCV) treatment landscape. Given that dermatologists frequently encounter HCV-infected patients, knowledge of the current treatment options and their utility in treating HCV-associated dermatologic disorders is important. In addition to highlighting the new treatment options, we review four classically HCV-associated dermatologic disorders - mixed cryoglobulinaemia (MC), lichen planus (LP), porphyria cutanea tarda (PCT) and necrolytic acral erythema (NAE) - and examine the role for all-oral direct-acting antiviral (DAA) regimens in their treatment. A literature search of English-language publications was conducted of the PubMed and EMBASE databases using search terms including 'hepatitis C', 'direct acting antivirals', 'cutaneous', 'mixed cryoglobulinemia', 'necrolytic acral erythema', 'lichen planus', 'porphyria cutanea tarda', 'rash', as well as specific drug names, related terms and abbreviations. Currently, limited data exist on the use of DAAs in HCV-infected patients with cutaneous side-effects, although treatment of the underlying HCV is now recommended for nearly all patients, with the new drugs offering much-improved dosage schedules and side-effect profiles. The most data exist for MC, in which several studies suggest that DAAs and achievement of sustained virologic response (SVR) improve cutaneous symptoms. Studies of both older and newer regimens are limited by their small size, retrospective nature, lack of appropriate controls and wide variability in study protocols. Given the strong association, screening for HCV should be considered in patients with MC, LP, PCT and NAE.