[Cicatricial pemphigoid disclosed by superficial desquamative gingivitis. Clinical and immuno-electron microscopic study of a case].

Six months before consulting, a 71-year old man developed buccal and genital erosions which gradually became worse. Physical examination showed signs of superficial desquamative gingivitis, wide erosions on the bony palate, erythemato-erosive balanoposthitis and 7 bullae or skin erosions on the upper part of the back. At histopathological examination of a cutaneous bulla there was dermoepidermal cleavage and an inflammatory infiltrate without eosinophils. At direct immunofluorescence, linear deposits of IgG and C3 were present along the basement membrane. A search for anti-skin autoantibodies was negative at indirect immunofluorescence but positive at immunoblotting (240 Kd band). The cicatricial pemphigoid was treated with dapsone alone in doses of 100 mg/day. Treatment was continued for 6 months, resulting in complete cure of the mucosal and cutaneous lesions. An immunoelectromicroscopic study, performed according to the technique described by Prost et al., on a fragment of skin from around the bullae, showed deposits of granular IgG in the lamina lucida and the lamina densa and deposits of C3 in the lamina densa. This case of cicatricial pemphigoid exhibited 3 features which are not usually found in bullous pemphigoid. Clinically, the buccal lesions were located on the gums and on the hard palate, i.e. where the mucosa adheres to the underlying bone through the periosteum. This location is habitual in cicatricial pemphigoid and differs from that of the bullous pemphigoid lesions which affect the free mucosa lining the cheeks and the soft palate. Treatment with dapsone was dramatically successful in our patient whose lesions disappeared in 6 months.(ABSTRACT TRUNCATED AT 250 WORDS)