Several studies have shown that treatment with dipeptidyl peptidase-4 inhibitors (DPP-4i) increases the risk of bullous pemphigoid (BP). The present study investigated the relationships of DPP-4i treatment with the clinical phenotypes and clinical course of BP. 

The study obtained data of 146 patients with BP by a retrospective medical record review and compared the bullous pemphigoid disease area index (BPDAI) between diabetic patients receiving DPP-4i treatment and those not receiving DPP-4i treatment. It used multivariable linear regression models to explore the association between the DPP-4i treatment and the BPDAI scores. 

The study found-

• Among 53 BP patients with diabetes, 33 developed BP during treatment with DPP-4i agents, among which vildagliptin was the most frequently used.
• Patients who developed BP while receiving DPP-4i treatment had significantly lower urticaria/erythema scores of the BPDAI than others.
• 69.2% of the patients who discontinued DPP-4i treatment underwent complete remission
• More favorable clinical course in patients with lower scores for urticaria/erythema than others. 

This study suggests that, in patients who developed BP while receiving DPP-4i treatment, a noninflammatory phenotype may imply a high likelihood that DPP-4i treatment contributes to the development of BP. Discontinuing DPP-4i should be carefully considered in close consultation with dermatologists.

Intern Med. 2022 Nov 2. doi: 10.2169/internalmedicine.0815-22. Epub ahead of print. PMID: 36328578.