Mucous membrane pemphigoid

Mucous membrane pemphigoid (MMP) is the subgroup of pemphigoid which predominantly affects mucous membranes. Scarring and limited skin involvement are possible. Several subtypes are classified based on clinical symptoms and target antigens, such as ocular mucous membrane pemphigoid, localized vulvar pemphigoid (LVP) and anti-laminin 332 MMP (anti-LN-332 MMP). Autoantibodies are directed against various structural proteins in the epidermal basement membrane zone (EBMZ), with the 180-kD antigen (BP180) as the main target antigen. Other antigens, such as BP230, the heterotrimeric glycoprotein laminin 332 and A6B4 integrin can also be targeted by autoantibodies. Various mucosa can be affected and are histologically characterized as nonkeratinized stratified squamous epithelium. The clinically heterogeneous disease is characterized by erosions and blistering of the oral mucosa (85%), conjunctiva (30-60%), and less frequently, the nasal mucosa (20-40%), esophagus (5-15%), pharyneal (20%) or laryngeal mucosa (5-10%) and anogenital mucosa (25%). Clinical severity is highly variable in the different subtypes of MMP. Previously, the term cicatricial pemphigoid was used for MMP. Progressive scar formation is a severe complication in ocular MMP and anti-LN-332 MMP, but scarring does not occur in all patients with MMP. Patient and doctors delay is frequently seen in MMP because of the heterogeneous clinical presentation and unfamiliarity among clinicians. For an accurate diagnosis, direct immunofluorescence microscopy (DIF) and detection of circulating autoantibodies in serum is essential. The multidisciplinary management and prognosis of MMP depends on the severity and extent of the disease and involves topical corticosteroids and immunomodulatory and immunosuppressive drugs.