Increased risk of bullous pemphigoid in dipeptidyl peptidase 4 inhibitors: A nationwide, population‐based, cohort study in Taiwan

Recent studies revealed the risk of bullous pemphigoid (BP) in patients with diabetes mellitus (DM) taking dipeptidyl peptidase 4 (DPP‐4) inhibitors. To clarify the relationship between taking DPP‐4 inhibitors and the risk of BP among patients with DM, we conducted a cohort study by using the National Health Insurance Research Database of Taiwan from 1 January 2009 to 31 December 2015. We identified 6340 patients with DM taking DPP‐4 inhibitors and 25 360 DM patients who had not taken DPP‐4 inhibitors during the 7‐year follow‐up period. Compared with the non‐DPP‐4 inhibitor group, patients taking DDP‐4 inhibitors had a higher risk of BP (adjusted hazard ratio [aHR], 2.382; 95% confidence interval (CI), 1.163–4.883; P = 0.017]. Among the DPP‐4 inhibitors available in Taiwan, vildagliptin showed the highest risk of BP (aHR, 2.849; 95% CI, 1.893–4.215; P