Mucous Membrane Pemphigoid

Abstract

Mucous membrane pemphigoid (MMP) is the subgroup of pemphigoid which affects mucous membranes. Several subtypes are classified based on clinical symptoms and target antigens, such as ocular mucous membrane pemphigoid (OMMP), 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, α6β4 integrin, and laminin 332, can also be targeted by autoantibodies. Clinically, MMP is characterized by erosions and blistering of the oral mucosa (85 %), conjunctiva (65 %), and, less frequently, the nose (20–40 %), esophagus (5–15 %), pharynx (20 %), larynx (5–10 %), and genitals (20 %). Clinical severity is highly variable in the different subtypes of MMP. Progressive scar formation is a severe complication in active disease in OMMP and anti-LN-332 MMP, resulting in blindness or upper airway obstruction when not treated accurately. Previously, the term cicatricial pemphigoid was used synonymously for MMP. However, at present, the term refers to the rare clinical phenotype with scarring skin lesions. Patient’s and doctor’s delay is frequently seen in MMP. For an accurate diagnosis, direct immunofluorescence microscopy (DIF) and detection of circulating autoantibodies in serum are mandatory. Management and prognosis of MMP depends on the severity and extent of the disease and involves a stepwise approach with first-choice treatment with oral corticosteroids (CS), often used in combination with adjuvant immunosuppressive drugs to reduce the adverse effects caused by long-term CS use.