Pemphigoid gestationis.

Pemphigoid gestationis is a rare autoimmune subepidermal bullous dermatosis that occurs during pregnancy and postpartum. Diagnosis is made on the basis of the presence of a subepidermal vesicle on routine histologic examination and of linear deposition of complement along the basement membrane zone of perilesional skin. The disorder is accompanied by severe pruritus and polymorphous bullous skin lesions. Clinical diagnosis is confirmed by histology and positive cutaneous immunofluorescence and immunoelectron microscopy tests (linear deposition of C3, with or without immunoglobulin G, along the basement membrane zone, within the lamina lucida, and localized to the proximal part of anchoring filaments of the epidermal fragment of salt-split skin). Enzyme-linked immunosorbent assay for pemphigoid gestationis antibody (BP180) is commercially available. If local treatment fails, systemic corticosteroid therapy should be administered. Oral corticosteroids are the therapeutic mainstay in pregnancy and postpartum. The prognosis is good for mother and child, except that there is a risk of preterm delivery and of moderate fetal growth restriction. Recurrence is possible during subsequent pregnancies. There is no significant maternal morbidity or mortality.