Bullous pemphigoid associated with dermatomyositis and colon carcinoma

It has been suggested that both bullous pemphigoid (BP) and dermatomyositis are associated with internal malignancies. However, there are no reports of the coexistence of these three conditions in one patient. We report the first case, to our knowledge. of coexistent BP, dermatomyositis and colon carcinoma. An 81-year-old Japanese woman was diagnosed with dermatomyositis based on muscular weakness and tenderness of the extremities, increased levels of circulating muscle enzymes and histological inflammatory changes in skeletal muscle and skin. Carcinoma of the sigmoid colon was detected during screening for internal malignancy; she was therefore surgically treated. Ten days after the operation, several large bullous eruptions appeared on her extremities. From the histopathological, immunofluorescence microscopy and BP180 ELISA study findings, we diagnosed the bullous eruptions as BP. Coexistence of BP with dermatomyositis or colon carcinoma is rare. Although the reason why our case exhibited these three disorders is not understood, it is suggested that these conditions may be associated with epitope spreading.