Pemphigoid Gestationis - Causes, Symptoms, Diagnosis, Complications, and Treatment

What Is Pemphigoid Gestationis?

Pemphigoid gestationis is a rare, itchy pregnancy-related autoimmune blistering skin condition clinically similar to the pemphigoid group of autoimmune blistering skin disorders. Other types of pemphigus or pemphigoid are not related to pregnancy. It usually happens in the pregnancy's second or third trimester. It often starts with itchy red bumps or blisters on the abdomen, trunk, and other body parts. Pemphigoid gestationis was earlier known as herpes gestationis, but it is understood that it has no connection to the herpes virus.

Who Gets Pemphigoid Gestationis?

Pemphigoid gestationis often affects women of all races during pregnancy's second and third trimesters or immediately after delivery. However, onset may be earlier in subsequent pregnancies. It may rarely be associated with trophoblastic tumors like choriocarcinoma or hydatidiform mole. It is estimated to occur in approximately 1 in every 50000 pregnancies.

What Causes Pemphigoid Gestationis?

Pemphigoid gestationis is an autoimmune disorder in which the immune system mistakenly attacks a normal component of the skin. In pemphigoid gestationis, the PG factor, a specific immunoglobulin type G (IgG) in the blood, binds to the BP-180 protein found in the skin's basement membrane resulting in tissue damage blistering. BP-180 protein is also located in the placenta. The placenta initiates the autoimmune response in pemphigoid gestationis. That's why this condition begins during pregnancy.

What Are the Symptoms of Pemphigoid Gestationis?

Pemphigoid gestationis manifests as intensely itchy urticaria-like rashes during mid to late pregnancy (13–40 weeks gestation). It initially begins as itchy red bumps around the navel. The rash spreads to other body parts, such as the trunk, buttocks, and arms, within a few days to weeks. However, the face, scalp, palms, soles, and mucous membranes are not usually affected.

After two to four weeks, the bumps often turn into large, tense blisters filled with clear yellowish fluid. However, some people may have no blisters but have raised red plaques of inflamed skin. The pemphigoid gestationis blisters may shrink or disappear on their own near the end of the pregnancy. However, 75 to 80 percent of women with this condition experience a flare-up around delivery time.

How Is Pemphigoid Gestationis Diagnosed?

Pemphigoid gestationis is usually clinically diagnosed when the features are typical, but it can be indistinguishable from other pregnancy eruptions in the early stages. Therefore, the following tests may be required:

Skin Biopsy: A local anesthetic or freezing spray is applied to a small skin area, and a tiny skin sample is removed and sent to the laboratory.

Direct Immunofluorescence: This test detects antibodies deposited in the skin.

Indirect Immunofluorescence: This laboratory technique detects specific antibodies circulating in the bloodstream that help distinguish pemphigoid gestationis from other autoimmune blistering disorders.

What Are the Complications of Pemphigoid Gestationis?

• Preterm birth.

• Low birth weight.

• Newborns may be small for gestational age.

The outbreaks of pemphigoid gestationis blisters in the first or second trimester may lead to adverse pregnancy outcomes. It is considered a high-risk pregnancy when pemphigoid gestationis occurs in the first or second trimester. Therefore, treatment with more careful monitoring and supervision is recommended.

Other complications include:

• Blistering on the infant can occur in approximately 10% of affected pregnancies. However, blisters in the baby spontaneously disappear with the natural clearance of maternal antibodies in 3–4 months.

• Secondary bacterial infection of the skin may leave scarring.

How Is Pemphigoid Gestationis Treated?

Treatment in pemphigoid gestationis aims to soothe itching, prevent blister formation, and treat a secondary infection.

Pharmacological Treament

• For mild symptoms, topical steroids can alleviate the skin by lowering the immune system activity at the site of the blisters.

• Systemic corticosteroids may be necessary in more extensive cases. However, minimum effective doses should be recommended to reduce the risk of potential adverse effects to both mother and fetus. When the condition improves, the dose can usually be reduced but should be increased in time to prevent a post-partum flare.

• Oral antihistamines may be used to ease the itch. These include:

  • Cetirizine.

  • Fexofenadine.

  • Loratadine.

• First-generation antihistamines, like diphenhydramine, can also be used for itching.

• Pyridoxine (B6) is known to be effective in some people.

• In severe cases, other treatments used after delivery include Intravenous immunoglobulin (IVIG).

  • Plasmapheresis.

  • Rituximab.

  • Dapsone.

  • Cyclophosphamide.

  • Methotrexate.

  • Tetracyclines with nicotinamide.

• Antibiotics are necessary for secondary bacterial infections.

At-Home Care

The doctor can also suggest home remedies to relieve the itch and discomfort of a mild pemphigoid gestationis. These can include:

• Keep the skin cool with ice or cold compresses.

• Stay in a cool or air-conditioned environment.

• Bath in Epsom salt or oatmeal preparations.

• Wear cool cotton clothing.

What Is the Outlook for Women With Pemphigoid Gestationis?

Pemphigoid gestationis is a rare skin condition in the second or third trimester of pregnancy. It can be itchy and uncomfortable but not life-threatening for the mother and fetus. However, there may be a slight risk for complications when the condition occurs early in a pregnancy, including preterm birth or low birth weight. Closer monitoring and supervision are necessary to avoid such risks. Pemphigoid gestationis often follows a fluctuating pattern of exacerbations and remissions during pregnancy. It usually improves in late pregnancy, followed by a flare at the delivery time (seen in 75 to 80 % of women). After delivery, the lesions typically go away within weeks or months. Rarely, pemphigoid gestationis can last for several years.

Conclusion:

Pemphigoid gestationis is a rare, itchy pregnancy-related autoimmune blistering skin condition, affecting during pregnancy's second and third trimesters or immediately after delivery. It clinically manifests as intensely itchy urticaria-like rashes in the trunk, buttocks, arms, and other body parts.

The diagnosis depends on clinical presentation and typical histopathological and laboratory findings. The prognosis is good, but it's associated with fetal risks. Although pemphigoid gestationis is self-limiting, symptoms can be reduced using topical and systemic corticosteroids and oral antihistamines. Thus, informing people about the natural course of the disease and treatment possibilities is critical.