Anti-programmed cell death protein 1-induced lichenoid changes of the nail unit: Histopathologic description

Abstract

Anti-PD-1: Anti-programmed cell death protein 1 irAEs: immune-related adverse events INTRODUCTION Tumor cells block our immune system and avoid being destroyed by inactivating T lymphocytes. Immunotherapy prevents this inactivation and allows the immune cells to fight tumor cells. The normal immunologic homeostasis is disturbed, and specific immune-related adverse events (irAEs) may develop: pneumonitis, hepatitis, colitis, endocrinopathies, and skin changes. The latter are one of the most frequent irAEs and occur in about 40% of the patients. Maculopapular rashes (14%-40% of the patients) and pruritus (10%-30% of the patients) are mainly reported, but lichenoid (in about 7% of the patients), psoriasiform or eczematous eruptions, as well as alopecia, vitiligo (5%-11%), bullous pemphigoid (\\1%), and sarcoid-like reactions have also been reported. Paradoxically, nail changes with immune checkpoint blockade have only been sporadically described in association with anti-programmed cell death protein 1 (anti-PD-1)/PD-L1 antibody therapy. We report herein 2 cases of nail lichenoid changes, confirmed by histopathology, in 2 patients receiving the anti-PD-1 monoclonal antibody nivolumab.