[Clinical characteristics of bullous pemphigoid in elderly patients with type 2 diabetes mellitus: The association with the use of dipeptidyl peptidase-4 inhibitors].

AIM: Bullous pemphigoid (BP) is an autoimmune skin disorder characterized by the production of autoantibodies. Several recent reports have described the occurrence of BP in diabetic patients treated with dipeptidyl peptidase-4 (DPP-4) inhibitors. However, the clinical features of BP in diabetic patients, particularly in those treated with DPP-4 inhibitors, have not yet been examined. The aim of this study was to clarify clinical characteristics of BP in elderly type 2 diabetic patients.

METHODS: We found cases of BP in 15 elderly type 2 diabetic patients (11 men, 4 women) and 20 non-diabetic patients (8 men, 12 women) from September, 2012 to September, 2016. These patients had all been treated with corticosteroid therapy. We investigated the participants' basic clinical characteristics and the course of BP treatment. The differences in variables between the two groups were analyzed using Wilcoxon's test and the chi-square test.

RESULTS: The mean age of type 2 diabetes patients with BP was 81.1±5.5 years. The mean HbA1c was 7.3±1.6%. A total of 87% of diabetic patients had been treated with DPP-4 inhibitors for 11.7 months prior to the BP onset. The diabetic patients had a lower prevalence of neurogenerative disease, severe ADL disabilities, and dementia than the non-diabetic patients. Furthermore, the diabetic patients with BP tended to be younger and more frequently male than those without diabetes. After stopping the DPP-4 inhibitors, the skin lesions were successfully treated with systemic corticosteroid therapy, and glycemic control was achieved using intensive insulin therapy. DPP-4 inhibitors were used in all cases where the aniti-BP180NC16a antibody showed negative conversion.

CONCLUSION: BP in patients with type 2 diabetes had different clinical features from that in non-diabetic patients, suggesting an association between BP and the use of DPP-4 inhibitors.