Radiation-induced pemphigus or pemphigoid disease in 3 patients with distinct underlying malignancies.

The cutaneous lesions of radiation-induced pemphigus or pemphigoid disease may resemble other skin diseases, including recurrent underlying cancer. We performed a computerized search of Mayo Clinic (Rochester, Minnesota) archives and identified 3 cases of pemphigus or pemphigoid disease that occurred after radiation therapy for breast, cervical, and metastatic malignancies, respectively. In 2 of these patients, the disease was initially confined to the irradiated field but subsequently disseminated to other parts of the patients' bodies, including mucosal surfaces. In all 3 patients, the blistering disease occurred 5 to 14 months after the onset of radiation therapy. All 3 were treated with corticosteroids and demonstrated complete recovery of the skin eruption after radiotherapy was discontinued. Although the precise mechanism of this cutaneous eruption is unknown, clinicians should be alert for this potentially serious complication and evaluate all cutaneous eruptions developing during and after radiotherapy.