INTRODUCTION: Bullous pemphigoid (BP) is a chronic, relapsing autoimmune blistering disorder commonly found in adults older than 60 years of age. It is mediated by autoantibodies directed against the hemidesmosomal proteins BP180 and BP230, which trigger an inflammatory cascade leading to blister formation. BP may present with pruritus, followed by an erythematous plaque or urticaria, and subsequently by bullae formation with or without mucosal involvement. It develops sporadically but can also be triggered by ultraviolet light exposure, radiation therapy, and medications such as dipeptidyl peptidase-4 inhibitor (DPP4i). Since 2006, the increasing use of DPP4i (also known as gliptins) for their good safety profi le in treating Type II Diabetes Mellitus has led to a further increase in the incidence of bullous pemphigoid.

CASE REPORT: This is a case of a 65-year-old hypertensive and diabetic elderly Filipino female presenting DPP4i (linagliptin)-induced bullous pemphigoid with an atypical dyshidrosiform pattern, negative direct immunofluorescence (DIF), and Enzyme-linked immunosorbent assay (ELISA) that is negative for anti-BP180 antibodies but positive for anti-BP230 antibodies.

CONCLUSION: The increasing use of DPP4i for diabetes mellitus for its good safety profile may be an essential contributing factor to the increasing incidence of BP in elderly hypertensive and diabetic patients with a simultaneous increasing incidence of atypical BP presentations such as the dyshidrosiform variant. Inability to recognize these factors carries significant therapeutic implications, including prolonged multidrug immunosuppression and increased patient morbidity and mortality.

KEYWORDS: Bullous pemphigoid, gliptin, ELISA