Anti-programmed cell death (PD)-1 therapy is emerging as the backbone of new standard of care immunotherapy for metastatic melanoma. Immune-related cutaneous events are observed in these patients.

We sought to describe cutaneous adverse events observed in patients with metastatic melanoma on anti-PD-1 therapy.

We reviewed the clinical and histologic information of all patients treated with single-agent anti-PD-1 therapy for metastatic melanoma at Westmead Hospital, Sydney, Australia, from May 2012 to February 2015.

Of the 82 patients included in the study, 34 had dermatology assessments. Forty (49%) developed a form of anti-PD-1-associated cutaneous adverse events. In all, 17% developed lichenoid reactions and eczema, and 15% developed vitiligo. An estimated 25% of patients were expected to develop their first lichenoid reactions within 8.3 months, and eczema and vitiligo within 10.3 months of therapy. These adverse events tend to appear together in patients on anti-PD-1 therapy.

The study was from a single center and clinical information was reviewed retrospectively in patients not referred to dermatology.

Anti-PD-1 therapy is associated with the development of immune-related cutaneous events. Lichenoid reactions, eczema, and vitiligo are the 3 most prevalent lesions observed in our population. There is a tendency for lichenoid reactions and eczema to occur with vitiligo.