Herpes gestationis.

Herpes gestationis is a rare, self limited bullous disease of pregnancy and the post-partum period with a presumed autoimmune basis. It is characterized clinically by pruritic, urticarial and vesiculobullous lesions, histologically by subepidermal vesicle formation, and immunopathologically by deposition of immunoreactants along the basement membrane zone. These features are shared by bullous pemphigoid which suggests that herpes gestationis may be a related entity. Immunoblotting studies have shown that herpes gestationis sera recognize a 180 kD epidermal antigen; in comparison, bullous pemphigoid sera most often detect a 220-240 kD antigen, but a significant number also recognize a 180 kD epidermal antigen, suggesting immunological similarities between these two diseases. Etiology and pathophysiology are not established, but an immunological basis is implicated by the frequent finding of C3 along the basement membrane zone of perilesional skin, the presence of herpes gestationis factor, increased incidence of HLA-DR3 and HLA-DR4, and association with other putative autoimmune diseases. Treatment usually consists of systemic corticosteroids.