Pembrolizumab‐Induced Subacute Cutaneous Lupus Erythematosus: A Case Report

Subacute cutaneous lupus erythematosus (SCLE) is an increasingly recognized cutaneous immune‐related adverse event of immune checkpoint inhibitors. We report an 83‐year‐old woman who developed pruritic annular and polycyclic plaques 10 weeks after starting pembrolizumab for oropharyngeal squamous cell carcinoma. Serology and histopathology were consistent with a diagnosis of SCLE. Pembrolizumab was discontinued, and corticosteroid treatment was initiated, with subsequent complete remission. Together with a review of ten previously published cases, this report characterizes pembrolizumab‐induced SCLE as a distinct, recognizable adverse event with a largely stereotyped clinicopathological presentation, occasionally extending toward a more severe, erythema multiforme/toxic epidermal necrolysis‐like phenotype. Awareness of this entity allows prompt recognition and treatment, generally leading to favourable outcomes.