Pembrolizumab‐induced acquired perforating dermatosis

Immune checkpoint inhibitors such as the programmed cell death‐1 (PD‐1) inhibitors, pembrolizumab and nivolumab, are frontline treatments for several types of solid‐organ malignancies. However, cutaneous adverse effects with PD‐1 inhibitor therapy are common and include lichenoid reactions, eczema, vitiligo and bullous dermatoses. Perforating dermatosis is a rare condition characterised by the extrusion of degenerate materials from the upper dermis through the epidermis and has rarely been reported in association with PD‐1 inhibitor therapy. Herein, we report the first case to our knowledge of acquired perforating dermatosis following treatment with pembrolizumab. Immune checkpoint inhibitors such as the programmed cell death‐1 (PD‐1) inhibitors, are frontline treatments for several types of solid‐organ malignancies. However, cutaneous adverse effects are common. Perforating dermatosis is a rare condition characterised by the extrusion of degenerate materials from the upper dermis through the epidermis and it has rarely been reported in association with PD‐1 inhibitor therapy. Herein, we report the first case to our knowledge of acquired perforating dermatosis following treatment with pembrolizumab.