[Paraneoplastic pemphigus].

Paraneoplastic pemphigus is an autoimmune bullous skin disease induced by underlying malignant or benign neoplasias. The diagnostic and immunological criteria of the disease were characterized by Anhalt et al. in 1990. Clinical symptoms are variable, consisting of polymorphous blistering skin eruption and severe, painful mucocutaneous ulcerations. In a subset of patients, only papular lesions develop, resembling lichen planus, or graft-versus-host disease; in some cases blisters may develop later. Severe dyspnea, progressive respiratory failure with clinical features of bronchiolitis obliterans is a rather frequent and severe complication. The diagnosis can be established with direct and indirect immunofluorescent studies and immunoblot analysis. The autoantigens identified to date include cytoplasmic proteins of the plakin gene family: envoplakin (210 kD), periplakin (190 kD), plectin (approximately 500 kD), desmoplakin I (250 kD), desmoplakin II (210 kD) and bullous pemphigoid antigen 1 (230 kD). The desmosomal cadherins: desmogleins 1 and 3, and desmocollins 2 and 3, as well as bullous pemphigoid antigen 2 (180 kD) and an undetermined 170-kD transmembranous antigen are also target autoantigens in the disease. The mortality rate is more than 90 percent. Beside treatment of the underlying tumor, a combination of systemic steroids with immunomodulators, cytostatic drugs, plasmapheresis, plasma exchange, intravenous gammaglobulin, or anti-CD20 monoclonal antibody (rituximab) may be the most appropriate treatment.