Bullous pemphigoid associated with dipeptidyl peptidase-4 inhibitor in primary care: Case report

Bullous pemphigoid is the most common bullous chronic autoimmune skin disease. Recent studies suggest dipeptidyl peptidase-4 inhibitors used in the treatment of type-2 diabetes as possible predisposing agents of bullous pemphigoid. It is thought to be important for primary care physicians, who are the most common referral point of patients and where drug use is examined in detail, to keep in mind that drugs such as dipeptidyl-peptidase-4 inhibitors may cause bullous pemphigoid and to refer to dermatology for early treatment. In this context, a 70-year-old female patient with a diagnosis of type 2 diabetes mellitus presented to our outpatient clinic with pruritic, erythematous bullous lesions diffusely distributed over the body, occurring one week after initiation of a vildagliptin-containing medication. There was no mucosal involvement. The patient initially received treatment with the presumptive diagnoses of allergy and scabies; however, as no improvement was observed, a detailed medical history was obtained. Based on the clinical findings, drug-induced bullous pemphigoid was suspected, and the vildagliptin-containing medication was discontinued. The patient was subsequently referred to the dermatology department. Histopathological examination and direct immunofluorescence findings were consistent with bullous pemphigoid. Following drug withdrawal and a short course of oral corticosteroid therapy, a marked improvement of the lesions was achieved. With this case, we aimed to draw attention to the approach of bullous pemphigoid disease developing as a result of vildagliptin use in a patient with type-2 diabetes who presented to primary care and to increase awareness on this issue.