The investigators conducted a prospective study which included all patients diagnosed with biopsy-proven BP in the Dermatology Department of Attikon hospital between April 1, 2009 and December 31, 2019. 113 consecutive patients with BP were identified. The investigators included the patients with type 2 diabetes and investigated the percentage of patients who were under treatment with DPP4-is. The specific DPP4-i prescribed was also documented.Medical information including patients' age, sex, other comorbidities and concomitant medications were also recorded. Furthermore, the investigators evaluated the effect of different types of treatment (topical steroids, systemic corticosteroids, immunosuppressive agents) on bullous pemphigoid.

Bullous pemphigoid (BP) is the most common chronic autoimmune skin disease which is characterized by the presentation of subepidermical blisters and mostly affects elderly patients . Recent studies have suggested that dipeptidyl peptidase-4 inhibitors (DPP-4is), an incretin-based drug for type 2 diabetes, as possible predisposing agents of BP . The objective of the study was to estimate the association between the use of DPP-4is and the development of BP in the setting of a tertiary university hospital and to raise awareness for everyday clinical practice, both among dermatologists as well as all physicians following patients with diabetes The study was designed as an observational prospective study.In the study included all patients who received a new diagnosis of BP and hospitalized in the Dermatology Department of our hospital between April 1, 2009 and December 31, 2019 Inclusion Criteria included a) biopsy proven bullous pemphigoid b) severe bullous pemphigoid c) recent manifestation of bullous pemphigoid (last four months).Exclusion Criteria included a) non bullous pemphigoid b) presentation of bullous pemphigoid more than four months c) treatment with DPP4is more than two years.

Overall, 113 consecutive patients with the diagnosis of BP were enrolled in the study.The investigators reviewed the percentage of patients with type 2 diabetes among all patients with BP.The number of patients who were under treatment with DPP4-is and the specific type of DPP4-is prescribed were also examined.

Inclusion Criteria:

• biopsy proven bullous pemphigoid
• severe bullous pemphigoid
• recent manifestation of bullous pemphigoid (last four months)

Exclusion Criteria:

• non bullous pemphigoid
• presentation of bullous pemphigoid more than four months
• treatment with DPP4is more than two years

In the study included all patients diagnosed with biopsy-proven BP in the Dermatology Department of Attikon hospital between April 1, 2009 and December 31, 2019.