Pemphigoid gestationis: A review

Pemphigoid gestationis is a rare autoimmune vesiculobullous skin disease cl osely related to the pemphigoid group of blistering disorders. It is unique in that it is most frequently associated with pregnancy. Diagnosis is made on the basis of the presence of a subepidermal vesicle on routine histolog ic examination and of linear deposition of the third component of complemen t along the basement membrane zone of perilesional skin. Abnormal expressio n of major histocompatibility complex class II molecules in the placenta ma y trigger the initiating immunologic event in this organ, which is followed by cross-reactivity with an antigen present in the skin and the characteri stic cutaneous signs of the disease. The immunogenetics of this disorder ar e interesting. A role for the involvement of major histocompatibility compl ex class II antigens seems likely because of the association with human leu kocyte antigens DR3 and DR4. Major histocompatibility complex class ill ass ociations have also been observed, as has a high frequency of anti-human le ukocyte antigen antibodies. We review the current understanding of the mole cular biologic and immunogenetic properties of this disease and discuss tre atment and potential impact on the fetus.