[Autoimmune bullous skin diseases]

Important advances have been made in the pathogenesis of autoimmune bullous skin diseases during the last 10 years. The aim of this review is to describe new types of autoimmune bullous skin diseases and to summarize progresses in the pathogenesis and treatment of these diseases.

Paraneoplastic pemphigus (PNP) is a new type of pemphigus, distinct from pemphigus vulgaris (PV) and pemphigus foliaceus (PF). It has both clinical and histological features of pemphigus, bullous pemphigoid (BP), erythema multiforme, and lichen planus, in patients with lymphoma. Numerous clinical types of autoimmune bullous skin diseases of the dermal epidermal junction have also been described. Analysis of patients' serum by immunoblotting and immunoprecipitation allowed the identification of target antigens of most of these diseases: PV and PF are due to the production of autoantibodies directed against adhesion molecules (desmoglein 1 and 3) that belong to the cadherin family. In PNP, autoantibodies are directed against plakins, a new family of desmosomal plaque proteins. BP, CP and pemphigoid gestationis are characterized by the production of autoantibodies mainly directed against two hemidesmosomal proteins: BPAG1 and BPAG2. The mortality rate of autoimmune bullous skin diseases is estimated between 10 and 40%, mainly due to infections and cardiovascular diseases. The potential interest of the first use of adjuvant therapies in addition to corticosteroids has not been demonstrated yet.

Due to the numerous side-effects of oral corticosteroids, many therapeutic trials are aimed at finding other treatments for the management of these diseases. Topical corticosteroids could be effective in BP, and even in some cases of pemphigus. New treatments using specific immunoadsorption of pathogenic autoantibodies with recombinant proteins will probably be available in the future.