Pemphigus foliaceus.

Pemphigus foliaceus (PF) and its endemic form fogo selvagem (FS) are autoimmune diseases characterized clinically by transient cutaneous superficial blisters. As opposed to pemphigus vulgaris (PV), patients lack mucosal involvement. Acantholysis in the upper epidermis is appreciated histologically. The serologic hallmark of PF and FS is the demonstration of IgG autoantibodies against the cell surface of keratinocytes. The specific target of these autoantibodies is desmoglein (Dsg) 1, one of the four known desmosomal cadherins, a family of transmembrane glycoproteins that play an important role in the dynamic regulation of intercellular adhesion. Compelling evidence has been compiled suggesting anti-Dsg1 autoantibodies in patients with PF and FS are pathogenic. The mechanism by which anti-Dsg autoantibodies induce loss of cell-cell adhesion in PF is under active investigation and is beginning to be elucidated. The study of the pathogenesis of PF and FS provides a unique opportunity to uncover insights that may contribute to our greater understanding of autoimmunity.