Bullous Pemphigoid in Patients with Non-small-cell Lung Cancer Complicated by Diabetes Mellitus Receiving Dipeptidyl Peptidase-4 Inhibitors and Immune Checkpoint Inhibitors: A Case Report of Two Patients and Review of Literature

Dipeptidyl peptidase-4 inhibitors (DPP-4is) are shown to be associated with the development of bullous pemphigoid (BP). Immune checkpoint inhibitors (ICIs) can lead to BP development. Therefore, the combination of DPP-4is and ICIs may predispose an individual to developing BP; however, few reports have focused on this issue. We herein report two patients with non-small-cell lung cancer complicated by diabetes mellitus (DM) who developed BP while receiving DPP-4is and ICIs. The clinical course of these patients suggests that the combination of DPP-4is and ICIs may carry a potential risk of BP development.