Inflammatory vulvar dermatoses following immune checkpoint inhibitor therapy.

Immune checkpoint inhibitors (ICIs) are associated with dermatologic adverse effects. We present 2 patients who developed inflammatory vulvar dermatoses after ICI therapy. The first patient—an 81-year-old with rectosigmoid adenocarcinoma—was treated initially with chemotherapy and radiation followed by pembrolizumab for local tumor regrowth. After her second dosage, she experienced vulvar pruritus with skin sloughing. An exam demonstrated bilateral hyperkeratotic white plaques on the labia majora (Figure, A). Biopsies confirmed psoriasiform epidermal hyperplasia with squamous atypia and perivascular lymphocytic inflammation. Pembrolizumab was discontinued, and she started clobetasol cream. After 2 months, her symptoms improved. Post-treatment exam showed residual skin thickening with resolution of skin sloughing, suggestive of ICI-related radiation recall. The second patient—a 68-year-old—received ipilimumab and nivolumab for urethral mucosal melanoma. Shortly after therapy initiation, she developed vulvar pruritus. Pelvic exam demonstrated thickened, edematous, hypopigmented labial skin (Figure, B). She started clobetasol cream, and symptoms resolved completely after 2 weeks.