Autoimmune Blistering Diseases: An Introduction

Autoimmune blistering diseases (AIBD) are a heterogeneous group of about a dozen entities that are clinically characterized by blisters and/or erosions on the skin or erosions on surface-close epithelia. AIBD can be classified into three subgroups, (1) pemphigus diseases with intraepithelial splitting and autoimmunity against mainly desmosomal proteins, (2) pemphigoid disorders with subepidermal blistering and autoantibodies directed against structural proteins of the basal membrane zone of the skin and orifice-close mucosal tissues, and (3) dermatitis herpetiformis where autoantibodies target two enzymes, transglutaminase 2 and 3. The involvement of the oral cavity is highly variable between the different AIBD. In pemphigus vulgaris, paraneoplastic pemphigus, and mucous membrane pemphigoid, oral lesions are present in all or the great majority of patients. In linear IgA diseases and epidermolysis bullosa acquisita, 50-70% of patients suffer from an oral involvement, while in bullous pemphigoid, the by far most frequent AIBD in Europe, Japan, and Northern America, only in 10–20% of patients the mouth is affected. In contrast, oral lesions in pemphigoid gestationis and dermatitis herpetiformis are found in less than 10% of patients and are absent in pemphigus foliaceus. This chapter will give an overview about the target antigens and diagnostic tools of AIBD.