What is the definition of Pemphigoid Gestationis?
Pemphigoid gestationis (PG) is a pregnancy-associated, autoimmune skin disorder. It usually begins abruptly during the 2nd or 3rd trimester of pregnancy, but it can begin at any time during pregnancy. Signs and symptoms often include the sudden formation of very itchy, red bumps and/or blisters on the abdomen and trunk, which may then spread to other parts of the body. Unrelenting itchiness (pruritus) often interferes with daily activities. Symptoms may improve at the end of pregnancy, but flares may occur during, or right after, delivery. While PG usually goes away on its own within weeks to months after delivery, it has been reported to persist for years in some cases. PG is caused by a woman's immune system producing autoantibodies and mistakenly attacking her own skin, but the trigger for autoantibody production is poorly understood. Treatment aims to relieve itching and prevent blister formation, and may involve the use of topical corticosteroids, oral corticosteroids, and/or oral antihistamines. The lowest effective dose of medication should be used in order to minimize the risk to the mother and fetus. The disorder may recur at a later time such as when menstruation resumes; with use of oral contraceptives; and/or during subsequent pregnancies.
What are the alternative names for Pemphigoid Gestationis?
- Gestational pemphigoid
- Herpes gestationis
What are the causes for Pemphigoid Gestationis?
Pemphigoid gestationis (PG) is an autoimmune disease, which means that an affected person's immune system mistakenly reacts against the person's own tissue. Immunoglobulin type G (IgG) autoantibodies, which normally protect the body against infections, are responsible in PG. The antibody attack results in inflammation and separation of the epidermis (outer layer of skin) from the dermis (inner layer of skin), allowing fluid to build up and create the blisters associated with PG. The exact, underlying triggers that cause a woman to develop PG are still being studied.
What are the symptoms for Pemphigoid Gestationis?
In most women with pemphigoid gestationis (PG), the condition begins abruptly as an extremely itchy, hive-like rash during mid to late pregnancy (during the 2nd or 3rd trimester). It often begins with red bumps around the abdomen and trunk, and then spreads to other parts of the body within days to weeks. Large, fluid-filled blisters may form on the affected areas of skin. Some people with PG do not develop blisters, but instead have large, raised patches (plaques).
Symptoms may improve or go away on their own towards the end of the pregnancy. However, most women experience a "flare" around the time of delivery. In most cases, symptoms go away again days after giving birth, but in some women the condition persists for weeks, months, or even years. The condition may occur again when menstruation resumes, with the use of oral contraceptives, or during future pregnancies.
Some babies of women with PG grow less than expected during pregnancy (small for gestational age) and/or are born before their due date (prematurely). While not common, some babies of women with PG are born with a rash similar to that seen in women with PG, but it typically goes away without treatment within a few weeks.
What are the current treatments for Pemphigoid Gestationis?
The goals of treatment for women with pemphigoid gestationis (PG) are to relieve itching, prevent blister formation, and treat any secondary infections. Treatment may depend on the severity in each person, and the risks and benefits of therapies need to be considered for both the mother and the fetus. In most cases, PG resolves spontaneously (on its own) within days after delivery, so treatment can usually be tapered off and stopped.
Topical corticosteroids may be used in milder cases, while oral corticosteroids are needed in more severe cases. Oral antihistamines may also be used to relieve itching. Intravenous immunoglobulin (IVIG) has also been reported to be effective. Certain immunosuppressive medications may also be effective, but their safety during pregnancy and/or breastfeeding must be considered.
How is Pemphigoid Gestationis diagnosed?
Pemphigoid gestationis shares some common features with other skin conditions of pregnancy, which can make diagnosis difficult. Diagnosis generally first requires a skin biopsy, which shows typical features of subepidermal blistering. The diagnosis may then be confirmed by direct immunofluorescence (DIF) staining of the biopsy to reveal antibodies. This is a lab technique that uses fluorescent dyes to identify antibodies bound to specific antigens. In some cases, circulating antibodies can be detected by a blood test (indirect immunofluorescence test).