Herpes Gestationis

Some cutaneous conditions are unique to pregnancy and the postpartum period. Others may affect both pregnant and nonpregnant women. Familiarity with these conditions is important in the evaluation of a pregnant patient with a rash or cutaneous lesion.

Herpes gestationis. This vesicobullous eruption can occur at any time during pregnancy but is most common in the second or third trimester or immediately after delivery. It is immunologically mediated.

Clinically, herpes gestationis (HG) typically presents with a pruritic eruption characterized by small, grouped vesicles with or without urticarial plaques. (The term “herpes” refers to the fact that these vesicles are grouped, not that this a viral disease.) These lesions usually begin around the umbilicus (Figure) and then become more extensive. The extremities, palms, and soles are often involved; mucous membrane lesions are rare. Frequently, there are crusted and excoriated lesions because of the intense pruritus.

HG resolves spontaneously in the postpartum period. In some women, the disease may flare immediately following delivery but then remit after weeks to months. It tends to recur with subsequent pregnancies or with the use of oral contraceptives.

The histopathologic changes of HG consist of an inflammatory infiltrate of eosinophils and lymphocytes in the dermis, subepidermal bullae, and focal necrosis of the basal cells. Direct immunofluorescence examination of perilesional skin shows characteristic linear deposition of C3 (and often IgG) along the basement membrane zone. Extensive symptomatic HG is usually treated with systemic corticosteroids. Occasionally the disease is limited and can be managed with topical corticosteroids alone. Newborns born to mothers who have been treated with high-dose corticosteroids must be monitored for adrenal suppression.

Controversy exists over the effect of HG on the fetus. While there appears to be an increased risk of prematurity and low birth weight, most recent reports have not confirmed an increased incidence of fetal mortality associated with this disease. In some cases, a rash may develop in the newborn after delivery, but this resolves spontaneously within a few days.