Newly Diagnosed Bullous Pemphigoid in a Patient Receiving Sitagliptin

Bullous pemphigoid (BP) is the most common autoimmune skin blistering disorder in the general population. The disease often presents in the seventh and eighth decades of life. Several identified triggers contribute to the pathogenesis of BP. One of these triggers includes the dipeptidyl peptidase-4 (DPP-4) inhibitors, linagliptin and vildagliptin. These medications are used primarily as therapy for type 2 diabetes mellitus. Current literature does not suggest that BP is a class effect of DPP-4 inhibitors. We present a case of an 81-year-old man who developed BP in the setting of another DPP-4 inhibitor, sitagliptin.