Immunopathology of oral mucosal ulcerative, desquamative, and bullous diseases. Selective review of the literature.

Cell/cell and cell/matrix adhesion proteins are responsible for maintaining the integrity of the mucosal lining of the oral cavity. Disease processes that destroy keratinocytes or adversely affect their adhesion to one another or to the subjacent basement membrane will result in erosions, ulcerations, and desquamations. Immunologic processes that have a deleterious effect on the integrity of the epithelial/basement membrane/submucosa complex are reviewed, and current research findings with respect to pathogenesis are discussed. In particular, T-cell-mediated hypersensitivity is involved in recurrent aphthous stomatitis and lichen planus; humoral-mediated immunity to cadherin intercellular adhesion molecules is important in the process of acantholysis in pemphigus vulgaris, and genetic defects and antibody-mediated processes give rise to junctional separation in epidermolysis bullosa and mucous membrane pemphigoid, respectively. An immune complex mechanism appears to underlie the pathogenesis of erythema multiforme.