In summary, radiation-induced pemphigus or pemphigoid disease, a rare but serious adverse effect of radiation therapy, should be considered in patients with new-onset blistering or erosive skin disease who have recently undergone irradiation. The accurate diagnosis of pemphigus or pemphigoid disease is important because such diseases often require long-term immunosuppressive therapy. A thorough history and skin examination must be obtained from all patients who receive radiation therapy and subsequently have blisters or eruptions on the skin, mucous membranes, or both. Appropriate diagnostic studies, including routine biopsy for histologic evaluation and direct immunofluorescence, serum for indirect immunofluorescence, and enzyme-linked immunosorbent assay, should be performed to exclude pemphigus or pemphigoid disease.
