Pemphigus

Pemphigus is a rare but life-threatening autoimmune disease of the skin and adjacent mucous membranes characterized by the loss of intraepithelial cell-cell adhesions (acantholysis) and autoantibodies against desmosomal proteins. Pemphigus vulgaris, pemphigus foliaceus, paraneoplastic pemphigus, and the rare IgA pemphigus comprise the pemphigus group. The diagnostic gold standard is the detection of autoantibodies in the skin/ mucous membranes by direct immunofluorescence. In recent years, the development of novel diagnostic systems has allowed the serological diagnosis of pemphigus in the great majority of patients. For this purpose, highly sensitive and specific ELISAs are used employing the ectodomain of desmoglein 1 (for pemphigus foliaceus) and desmoglein 3 (for pemphigus vulgaris) as well as envoplakin (for paraneoplastic pemphigus). By several in vitro and in vivo systems, the pathogenic relevance of autoantibodies against desmoglein 1 and 3 has been clearly demonstrated. Treatment of pemphigus is challenging and often limited by side effects of the applied immunosuppressants. High dose systemic corticosteroids are the therapeutic backbone and are combined with corticosteroid-sparing immunosuppressants like azathioprine, mycophenolate mofetil, mycophenolate-sodium, and cyclophosphamide. The anti-CD20 antibody rituximab, immunoadsorption, and high-dose intravenous immunoglobulin have been successfully used in refractory patients.