Vesiculo-bullous mucocutaneous disease: benign mucous membrane and bullous pemphigoid.

Bullous pemphigoid (BP) and benign mucous membrane pemphigoid (BMMP) are autoimmune diseases characterised by subepithelial bulla formation and showing substantial overlap in clinical signs and symptoms. BP principally involves skin and BMMP the oral mucosa and eyes. The gingiva are affected in 90% of cases of BMMP and buccal mucosa and palate in up to 30%. Lesions may heal with scarring. Extension into the pharynx and esophagus causes sore throat and dysphagia. Severe ocular involvement may cause blindness. Bulla formation is attributed to complement activation, following IgG binding to the basement membrane zone, with subsequent polymorphonuclear leukocyte accumulation. The target antigen in BP is a 180-230 kD protein associated with the basilar membrane of basal keratinocytes. The gene encoding the BP antigen has been partially cloned. It is likely that the same antigen is involved in BMMP, but the mechanism of scarring is not understood. Treatment of BP and BMMP includes systemic steroid and azathioprine therapy and topical steroids.