[Pemphigoid of the mucous membranes. The clinical, histopathological and immunological aspects and current therapeutic concepts]

Mucous membrane pemphigoid (MMP) is a chronic disease of unknown etiology frequently involving oral cavity and eye and sometimes also pharyngeal, laryngeal, oesophageal and genital mucosae. It is characterized histologically by a sub-epithelial blister and by a typical direct immunofluorescence feature showing linear binding of IgG and C3 to the basement membrane zone (BMZ). The predominance of mucosal involvement or the lack of skin lesions distinguish MMP from bullous pemphigoid. Oral mucosal presentation of MMP is quite variable from chronic erythematous lesions to erosions covered by a fibrinous slough produced by bullae rupture involving mainly gingiva, buccal mucosa and palate. Because eye manifestations of MMP are common and blindness may develop, an ophthalmological examination is mandatory in these patients, although recent data suggest that pure ocular pemphigoid, oral pemphigoid and MMP with cutaneous lesion could be different diseases. Further immunological and biochemical studies are needed to better characterize these pathologies. It is generally considered that blister formation in MMP is the result of immunoglobulin deposition leading to complement activation in the BMZ, but there are not specific pathogenetic data regarding oral pemphigoid. Multiple therapeutic options exist including topical and systemic corticosteroids associated or not to other immunosuppressive drugs, dapsone and tetracycline but there do not exist treatment modalities generally accepted.