Autoimmune blistering diseases: histologic meaning.

The histologic picture of intraepidermal and subepidermal autoimmune bullous dermatoses is presented. Histologic changes are described according to the temporal evolution of lesions, with special reference to crucial elements of the histologic differential diagnosis. The diagnosis of autoimmune bullous dermatoses is complex, mostly requiring additional immunofluorescence assays along with histoclinical correlation to detect the antibodies or target antigen by the methods of molecular biology or immunohistochemistry. Additional tests to reach an accurate diagnosis in various autoimmune bullous dermatoses are briefly described, emphasizing the need of proper integration of all clinical and laboratory data. Although frequently inadequately specific, the histologic finding provides a link between clinical findings and target molecular studies in autoimmune bullous dermatoses.