Four cases of mucous membrane pemphigoid with clinical features of oral lichen planus

Background Mucous membrane pemphigoid (MMP) and oral lichen planus (OLP) show similar clinical features on the oral mucosa. As clinical manifestations of oral mucosal lesions, MMP shows blisters and erosions, whereas OLP shows lace-like whitish lesions in an annular arrangement with erythema and erosions. Histopathologically, MMP shows subepithelial bullae with infiltrates of lymphocytes and neutrophils, whereas OLP shows band-like interface infiltration of lymphocytes with damage in basal cells. However, these two diseases are frequently difficult to distinguish both clinically and histopathologically. Objectives We report four patients with oral MMP who showed OLP-like clinical and histopathological lesions. Methods We performed direct immunofluorescence, indirect immunofluorescence of normal human skin and 1 m NaCl-split skin, enzyme-linked immunosorbent assays for BP180, BP230, and desmogleins 1 and 3, and immunoblotting of normal human epidermal and dermal extracts, recombinant proteins of BP180-NC16a and -C-terminal domains, concentrated culture supernatant of HaCaT cells, and purified laminin-332. Results The results of various immunological studies suggested the diagnoses of various types of MMP for all four patients. Conclusions Because MMP and OLP require different treatments, all dentists and dermatologists should have knowledge about the disease entity and the serological diagnostic methods for various types of MMP.