Lee H, Chung HJ, Pawar A, et al. - Using data from 2 large commercial insurance claims databases (Optum Clinformatics Data Mart from October 17, 2006, to December 31, 2018, and IBM MarketScan Research Database from October 17, 2006, to December 31, 2017) and Medicare data from January 1, 2006, to December 31, 2016, researchers conducted this cohort study to describe the incidence rate of bullous pemphigoid associated with dipeptidyl peptidase–4 (DPP-4) inhibitor use compared with second-generation sulfonylureas. In total, 1,664,880 patients who started DPP-4 inhibitors (51.0% female; mean [SD] age, 63.9 [9.7] years), and sulfonylurea (50.4% female; mean [SD] age, 63.9 [9.9] years) were involved. Data reported that the incidence rate of bullous pemphigoid per 1,000 person-years was 0.42 in the DPP-4 inhibitor group vs 0.31 in the sulfonylurea group. Compared with patients who started second-generation sulfonylurea therapy, those who initiated DPP-4 inhibitor therapy had a higher risk of bullous pemphigoid. Physicians should be aware of this unusual adverse effect of DPP-4 inhibitors in patient subgroups that are older, white, and users of linagliptin.