Dipeptidyl Peptidase-4 Inhibitors Cause Bullous Pemphigoid in Diabetic Patients: Report of Two Cases

Bullous pemphigoid (BP) is an autoimmune disorder characterized by the production of autoantibodies against two antigens (BPAG1 and 2) and can be induced by drugs (1,2). Recently, the development of BP was reported in diabetic patients treated with dipeptidyl peptidase-4 inhibitors (gliptins) plus metformin (3). However, it remains unknown whether gliptins alone or in combination with metformin are responsible for the induction of BP. We report two diabetic patients who developed BP shortly after addition of vildagliptin to their metformin monotherapy. A 59-year-old woman and a 67-year- old man, both with type 2 diabetes that had been controlled with metformin for 6 and 3 years, respectively, presented with an 1- and 3-month history of pruritic …