[Atypical and/or systemic dermatologic disorders related to immune checkpoint inhibitors: A review]

Immunological checkpoint inhibitors are now part of the oncological therapeutic arsenal in many solid cancers and malignant blood diseases, at the cost of immuno-mediated toxicities, of which dermatological disorders are among the most frequent. The most common, following treatment with anti-PD1 or anti-CTLA4, are maculopapular erythema, pruritus, vitiligo, or lichenoid lesions, but other more atypical conditions may lead to the internist being called upon. Here, we present a case series of these less common dermatological manifestations including fasciitis, dermatomyositis, scleroderma, granulomatosis and immune-induced vasculitis. Some manifestations appear similar to the primary forms or seem to correspond to paraneoplastic syndromes, but some diagnostic and therapeutic particularities are specific to ICI toxicity that the internist must be aware of.