Two Cases of Bullous Pemphigoid Induced by Vildagliptin

ABSTRACT

Purpose: Bullous pemphigoid is an autoimmune blistering disorder that commonly develops in elderly subjects who are prone to an increased risk of mortality and morbidity. Although a few cases of dipeptidyl peptidase-4 inhibitors have been reported earlier, the etiology of bullous pemphigoid is not entirely clear.

Case Report 1: An 81-years-old man presented with bullous pemphigoid after 28 months of treatment with repaglinide, vildagliptin, and metformin. Since his skin lesions were not improving with topical treatment of clobetasol propionate 0.05% ointment, so then he was started on methylprednisolone and azathioprine; however, the skin lesions sustained even then. Remission was achieved only after the withdrawal of vildagliptin.

Case Report 2: A 64-years old man who was on insulin glargine, insulin aspart, and vildagliptin for 12 months, presented with BP of skin and laryngeal mucosa. The skin lesions were resolved after discontinuation of vildagliptin, but the laryngeal involvement continued to exist. Methylprednisolone and azathioprine treatment, for mucosal lesions, were started and continued for six months.

Conclusion: Only a few cases of gliptin induced bullous pemphigoid are present in the literature. One of our cases is the first to demonstrate the latest onset of vildagliptin associated skin reactions while the other case is the first to demonstrate vildagliptin associated mucosal involvement. The exact mechanism of these reactions is unknown, however, it is proposed that it could be caused by modified immune responses. Our cases support the finding that there is a risk of bullous pemphigoid development in patients exposed to vildagliptin. Therefore, it is important to be aware of this risk and stop the vildagliptin treatment in such patients.