Bullous pemphigoid is a blistering disease of the elderly that often is self-limited. It is apparently caused by autoantibodies against antigens of the basal cell hemidesmosome. There is apparently more than one antigen, but the most significant has a molecular weight of about 230 kD and the second most frequently detected antigen has a lower molecular weight of about 166 to 180 kD. The subepidermal blister presumably is produced by autoantibody binding along the basement membrane zone, followed by a complex series of inflammatory events. Conservative use of oral and topical corticosteroids often is sufficient to control the disease. Cicatricial pemphigoid has similar immunologic features, but it is not known if the same antigens are immunogenic in this disease. Scarring of mucosal surfaces due to recurrent blistering can result in blindness, asphyxiation, and esophageal stenosis. Treatment is more difficult and often requires short-term, intensive immunosuppression with cyclophosphamide.