Lichen planopilaris associated with pembrolizumab in a patient with metastatic melanoma

Pembrolizumab, a programmed cell death receptor 1 (PD-1) inhibitor, has been used effectively for treatment of metastatic melanoma.1 Reported cutaneous adverse events ascribed to PD-1 inhibitors include lichenoid reactions such as lichen planus of the skin and oral mucosa, lichen planus pemphigoides, and lichenoid drug eruptions, as well as alopecia areata and vitiligo.2-5 We present a patient with metastatic melanoma who had lichen planopilaris (LPP) after receiving pembrolizumab. We find no previous report in the literature of LPP in association with PD-1 inhibitors.