Pemphigoid gestationis

Pemphigoid gestationis is a rare, autoimmune blistering condition occurring in 1 in 50 000 pregnancies Bechtel, 2018. It usually develops in the second or third trimester, but can also appear in the first week postpartum.

Pemphigoid gestationis initially presents in the periumbilical area, with intensely itchy urticarial plaques. Differentiating early pemphigoid gestationis from polymorphic eruption of pregnancy can be difficult. Umbilical involvement is more common in pemphigoid gestationis, compared to polymorphic eruption of pregnancy.

Grouped papulovesicles develop, coalescing to form large bullae, and blistering often occurs at the edges of the urticarial plaques, resulting in a ‘string of pearls’ appearance. See here for a photo of pemphigoid gestationis on the lower legs and feet.

Figure 1. Pemphigoid gestationis on lower legs and feet

Note:

Reproduced with permission from the A-Z of Skin [digital]. Australasian College of Dermatologists. Sydney. https://www.dermcoll.edu.au/

Diagnosis of pemphigoid gestationis is confirmed by a dermatologist, after review of serum Immunoglobulin G (IgG) BP180 antibodies, and skin biopsy with histology and direct immunofluorescence.

Treatment of pemphigoid gestationis can be difficult, and aims to reduce pruritus. Depending on severity, systemic or topical corticosteroids, antihistamines, or a combination of these may be used by the dermatologist.

Pemphigoid gestationis may have a chronic relapsing course. It can flare at the time of delivery, and tends to recur in subsequent pregnancies. It may recur with the use of oral contraceptives or with menses. Trial of other steroid-sparing agents may be required with many patients experiencing refractory or persistent diseaseGenovese, 2020.