Digital ulcerative lichenoid dermatitis in a patient receiving anti-PD-1 therapy

We describe a case of digital ulcerative lichenoid dermatitis resembling ulcerative cutaneous lichen planus that occurred during pembrolizumab therapy for oral squamous cell carcinoma. The patient developed a painful ulcer on his index finger 18 months into therapy. Biopsy revealed epidermal ulceration with intense lichenoid dermatitis. Immunohistochemical study revealed intense CD8 positivity at the ulcer's edges and marked CD163 positivity at its base. Although idiopathic forms of this type of lichenoid dermatitis...
Source: Dermatology Online Journal - Category: Dermatology Source Type: research