Early-onset fatal toxic epidermal necrolysis after first-cycle enfortumab vedotin in an elderly patient with metastatic urothelial carcinoma.

An 86-year-old man with metastatic urothelial carcinoma developed fever, mucosal erosions, and rapidly progressive widespread erythema shortly after completing the first cycle of enfortumab vedotin (EV). Skin biopsy showed full-thickness epidermal necrosis consistent with toxic epidermal necrolysis (TEN). EV was discontinued and high-dose corticosteroids, intravenous immunoglobulin, and intensive supportive care were administered; however, the patient deteriorated rapidly and died of septic shock. This case demonstrates that EV-induced TEN may occur early and progress fulminantly, underscoring the need for prompt recognition and early dermatologic consultation.