Endocrine Abstracts

Introduction & Objective: Bullous pemphigoid (BP) is a chronic immune-mediated blistering disease that mainly affects the elderly. This affection can be triggered by multiple factors such as drugs. Gliptins are one of the most incriminated drugs in the drug-induced bullous pemphigoid (DIBP). Our objective was to determine the characteristics of this pathology associated with the use of this medication through two cases of BP confirmed by histology and direct immunofluorescence.

Cases presentation: Two male patients aged 67 and 74 treated with linagliptin for type 2 diabetes mellitus consulted for a pruritic bullous dermatosis. The pruritus have been evolving for 1 month after the introduction of linagliptin in the first patient and after 1 year in the second patient with the appearance of bullous lesions after 3 and 1 months respectively. The clinical presentation was large, fluid-filled and tender blisters of different sizes with an erythematous base in both cases. These lesions were generalized with a predominant acral location. Mucosal involvment was present in one patient with post-bullous erosions on the inner side of the cheeks. The clinical diagnosis of BP was suspected and completed by histology and direct immunofluorescence. The interruption of linagliptin was indicated in both patients. One patient received systemic corticosteroid therapy (0.5 mg/kg/day) and the other patient was treated with topical corticosteroid. The two patients showed significant improvement with no evidence of relapse after 3 months of follow-up.

Conclusions: Gliptins, also known as dipeptidyl peptidase-4 (DPP-4) inhibitors are widely used in the treatment of type 2 diabetes mellitus. This treatment have increasingly been implicated in DIBP and its risk doubles. The pathophysiology remains unclear but the inhibition of DPP-4 receptors results in activation of proinflammatory cytokines and an inflammatory response leading to dermoepidermal damage. Males are more likely to develop this condition and the median age is 70, as in our study. Clinically, many reports concluded on the absence of difference between gliptin-induced BP and classical BP. Non inflammatory blisters with a smaller sized and less erythematous bases in limited distribution were found in some series. The age of onset after the initiation of gliptin therapy varied from 1 month to 4 years. In the literature, histological findings showed scant lesional infiltration of eosinophils and direct immunofluoresence is more positive in this group. The treatment consists of the withdrawal of gliptins which together with steroid administration leads to complete remission and morbidity reduction.