[Unilateral localized bullous pemphigoid following radiotherapy]

A 74-year-old woman presented with a four-week history of locally expanding, highly pruritic urticarial plaques, bullae and erosions on her left breast. She had undergone surgery for an infiltrating ductal carcinoma of the same breast six months before and received intra- and postoperative radiotherapy (RT) followed by adjuvant hormonal anticancer treatment. Histopathological, immunological and serological data confirmed the diagnosis of localized bullous pemphigoid (BP) and treatment with systemic and local corticosteroids led to a sustained remission. After excluding other factors, we concluded that RT was the most likely trigger of her localized BP.