Relapse of pemphigus foliaceus initiating at the site of irradiation in an elderly male with laryngeal carcinoma: Illustrating the concept of immunocompromised cutaneous district.

Radiotherapy-induced or -aggravated pemphigus is not a common occurrence with only a few cases reported so far. The radiation disrupts the local immune regulation and alters the antigenicity of keratinocytes, but the exact etiology is not clear. We report a case of an elderly man operated for laryngeal carcinoma who presented with recurrence of pemphigus foliaceus lesions starting at the irradiation site. The appearance of vesiculobullous lesions at the site of irradiation should be evaluated thoroughly to rule out immunobullous diseases.