Dermatological side effects of hepatitis C and its treatment: patient management in the era of direct-acting antivirals.

Dermatological adverse events (AEs) are an existing concern during hepatitis C virus (HCV) infection and peginterferon/ribavirin treatment. HCV infection leads to dermatological and muco-cutaneous manifestations including small-vessel vasculitis as part of the mixed cryoglobulinemic syndrome. Peginterferon/ribavirin treatment is associated with well-characterized dermatological AEs tending towards a uniform entity of dermatitis. New direct-acting antivirals have led to significant improvements in sustained virologic response rates, but several have led to an increase in dermatological AEs versus peginterferon/ribavirin alone. In telaprevir trials, approximately half of treated patients had rash. More than 90% of these events were Grade 1 or 2 (mild/moderate) and in the majority (92%) of cases, progression to a more severe grade did not occur. In a small number of cases (6%), rash led to telaprevir discontinuation, whereupon symptoms commonly resolved. Dermatological AEs with telaprevir-based triple therapy were generally similar to those observed with peginterferon/ribavirin (xerosis, pruritus, and eczema). A few cases were classified as severe cutaneous adverse reaction (SCAR), also referred to as serious skin reactions, a group of rare conditions that are potentially life-threatening. It is therefore important to distinguish between telaprevir-related dermatitis and SCAR. The telaprevir prescribing information does not require telaprevir discontinuation for Grade 1 or 2 (mild/moderate) rash, which can be treated using emollients/moisturizers and topical corticosteroids. For Grade 3 rash, the prescribing information mandates immediate telaprevir discontinuation, with ribavirin interruption (with or without peginterferon) within 7 days of stopping telaprevir if there is no improvement, or sooner if it worsens. In case of suspicion or confirmed diagnosis of SCAR, all study medication must be discontinued.