Oral Mucous Membrane Pemphigoid With Positive Nikolsky’s Sign: A Case Report

Mucous membrane pemphigoid (MMP) is a rare inflammatory, autoimmune, and subepithelial vesiculobullous disease in which tissue-bound autoantibodies are produced against one or more components of the basement membrane. Oral lesions of the pemphigoid begin in the form of vesicles or bullae that often involve throughout the mouth but may be confined to specific areas, especially the gingiva, in a pattern known as desquamative gingivitis. The positive Nikolsky's sign is characteristic of pemphigus vulgaris, in which a blister can appear on the normal-appearing skin if exerting lateral pressure, and is very rare in the mucosa and other vesiculobullous diseases. Here we report a case of mucous membrane pemphigoid that developed as desquamated gingivitis in a 46-year-old woman with positive Nikolsky's sign in the gingival mucosa. In the histopathologic view, a subepithelial cleft was observed. The results of direct and indirect immunofluorescence tests and related therapeutic interventions are also presented. Positive Nikolsky's sign can be observed in the mucosa as well as in the mucous membrane pemphigoid in addition to pemphigus vulgaris, and vesiculobullous lesions should be diagnosed based on the sum of clinical, histopathological, and immunofluorescence findings.