Radiotherapy-induced pemphigus vulgaris: a challenging case of extensive mucocutaneous ulcerations and literature...

To report a challenging case of radiotherapy-induced pemphigus vulgaris presenting as extensive mucocutaneous ulcerations and to highlight diagnostic and therapeutic considerations.

A 59-year-old man with a history of tobacco and alcohol use presented with a persistent ulcer on the floor of the mouth. Incisional biopsy confirmed squamous cell carcinoma. The patient underwent surgical resection with cervical lymph node dissection, followed by adjuvant radiotherapy (33 fractions, cumulative dose of 6600 cGy) and cisplatin chemotherapy. Approximately one month after completion of radiotherapy, he developed painful erosive lesions with thick crusting involving the lips and malar region, which rapidly extended to the chin, neck, and back, with extensive epithelial loss. Skin biopsy was performed for diagnostic clarification.

Histopathological analysis confirmed the diagnosis of pemphigus vulgaris. Paraneoplastic pemphigus was excluded based on imaging studies showing no evidence of active malignancy. The patient required 40 days of hospitalization with nutritional support via a nasoenteric tube. Treatment with high-dose systemic prednisone resulted in progressive clinical improvement and lesion healing. At 8 months of follow-up, the patient remained disease-free.

Pemphigus vulgaris may represent a rare but severe complication following radiotherapy. Early recognition and prompt immunosuppressive treatment are essential to reduce morbidity and improve patient outcomes.