Mucous Membrane Pemphigoid

This chapter is focused on mucous membrane pemphigoid (MMP), a group of acquired subepidermal auto-immune blistering diseases that predominantly affect the mucous membranes. MMP is caused by autoantibodies directed against structural proteins of the dermal-epidermal junction including BP180, BP230, type VII collagen, and laminin 332. This autoimmune response leads to erosions and blisters that may be present on one or multiple mucosal sites. The oral cavity is most commonly involved, whereas the disease may also affect the conjunctiva, the nasal, pharyngeal, laryngeal, esophageal, or genital mucosa. Besides mucosal lesions, the skin can also be involved, however not dominantly. An important aspect of inflammatory lesions on mucosal sites other than the oral cavity, is the tendency to heal with scarring. Scar formation of the laryngeal and esophageal mucosa can be life-threatening by causing airway obstruction. Moreover, irreversible blindness may occur in ocular MMP if the disease is not recognized or treated accurately. Diagnosis relies on the detection of complement C3, IgG or IgA autoantibodies in a linear pattern along the basement membrane zone by direct immunofluorescence microscopy of a mucosa or skin biopsy. In addition, circulating autoantibodies can be detected in the serum, and provide information on the target antigen(s). Treatment is often multidisciplinary and challenging. It mainly exists of immunosuppressive or immunomodulating drugs. Short time disease control can be achieved by oral corticosteroids, while longtime disease control can be established by tetracyclines, dapsone, mycophenolate mofetil, methotrexate, azathioprine, cyclophosphamide, or rituximab. In this chapter, we provide clinical clues for recognition of MMP, provide an overview of the diagnostic algorithm, and shortly discuss therapeutic options.