Herpes gestationis (Pemphigoid gestationis).

Herpes gestationis, coined by Milton in 1872, or gestational pemphigoid is the most clearly characterized dermatosis of pregnancy. It is a rare vesiculo-bullous eruption that develops during the last trimester or even postpartum and creates severe pruritus. Its etiology is unknown, but it is considered as an autoimmune-mediated dermatosis closely related to the pemphigoid group. Herpes gestationis is associated with a positive C3 deposition along the base of the epidermis in salt-split skin, with increased frequency of HLA-DR3 and also the combination DR3 and DR4. It has a high risk of prematurity and disappears in the postpartum period within weeks or months.