Oral lichenoid reaction showing multiple ulcers associated with anti‐programmed death cell receptor‐1 treatment: A report of two cases and published work review

Anti-programmed cell death receptor-1 (PD-1) antibodies represent an effective treatment opinion for advanced melanoma and non-small-cell lung cancer, as well as other cancerous entities. Immune checkpoint inhibitors such as anti-PD-1 antibody result in a unique side-effect profile, commonly described as immune-related adverse events (irAE). These irAE affect the skin, gastrointestinal tract, liver, endocrine system and other organ systems. We report two cases of oral lichenoid reaction showing multiple ulcers associated with nivolumab treatment. Both patients presented with multiple ulcers covered with fibrinous plaque over the entire oral mucosa, lips and tongue. Histopathological examination of ulceration showed epithelial necrosis and subepidermal clefts with dense band-like layers of lymphohistiocytic infiltrate within the upper dermis. Nivolumab was interrupted in both cases. Case 1 responded well to topical corticosteroids. Case 2 required oral corticosteroids, however, nivolumab could be restarted without recurrence of oral ulcers. We provide a comprehensive review of reported cases of lichenoid reaction showing multiple oral ulcers associated with anti-PD-1 therapy to date. Early recognition and management may improve treatment, avoid discontinuation of life-saving therapy and maintain quality of life in these patients.