Polymorphic Eruption of Pregnancy
Also known as Pruritic Urticarial Papules and Plaques of Pregnancy, Polymorphic Eruption of Pregnancy (PEP) is the most common skin disorder in pregnancy characterized by a rash and significant itching on the abdomen.
Although other skin conditions during pregnancy also lead to intense itching, PEP is considered self-limiting, does not harm the fetus, and does not lead to more serious conditions. However, some women can find the itching so bothersome they may require medicated creams if lifestyle changes do not provide any relief.
Fortunately, the condition can go away by itself even before delivery, usually within 4 to 6 weeks from onset, or within 2 weeks postpartum.
Women should talk to their HCP anytime they have itching or other skin-related problems during pregnancy. HCPs will want to rule out other possible conditions and can help provide tips and management techniques to relieve itching.
Background
Polymorphic Eruption of Pregnancy (PEP) is an inflammatory skin disorder that leads to a rash and significant itching; it is considered the most common dermatological condition of pregnancy. It might also be referred to as Pruritic Urticarial Papules and Plaques of Pregnancy (PUPPP), toxemia of pregnancy, or prurigo of pregnancy.
PEP is reported to develop in 0.5% of pregnancies, or 1 in 160 to 300 pregnant women. In women who are pregnant with multiples, the risk may be 8 to 12 times greater.
With an average live birth rate of 4 million deliveries in the United States, this would equate to 20,000 pregnant women with this condition every year.
Signs and Symptoms
PEP presents as a rash similar to hives in or near stretch marks on the abdomen, eventually spreading to the rest of the abdomen, breasts, arms, and legs, but usually does not affect the face (but can). These lesions can also have a halo-looking effect in some women. Itching usually starts at the abdominal stretch marks and can be unbearable.
Presentation of PEP is almost always in the third trimester but can also present in the immediate postpartum period (rare). The rash usually resolves with 4 to 6 weeks, even prior to delivery.
Note: Itching is related to two other more serious skin conditions during pregnancy – however, in general, Intrahepatic Cholestasis of Pregnancy (ICP) has no rash, and Gestational Pemphigoid includes blisters. Women should always call their HCP with any unusual skin changes during pregnancy.
Causes/Risk Factors
The cause of PEP is unknown and is likely caused by more than one factor; however, it is not considered a genetic disorder.
Although “stretch” appears to be a logical factor (especially with a high risk in multiples and third trimester prevalence), this is very inconsistent, as well as associations between PEP and hormones, maternal weight gain, and fetal growth. Further, even though postpartum PEP is rare, its occurrence also seems to refute stretching as the only factor.
However, it is theorized that extreme stretching of abdominal skin can damage underlying connective tissue leading to an inflammatory response within the body, resulting in a rash and intense itching – a similar process that occurs in the development of stretch marks. Postpartum itching may also be explained by the sudden decrease in stretch that provokes an inflammatory reaction.
Another sign of stretch as a primary causal factor is the low recurrence rate. Most women experience PEP in their first pregnancy; only about 5% to 10% of women will have PEP in a subsequent pregnancy. This low rate of recurrence could indicate the abdominal skin is already stretched and accustomed to growth for a second pregnancy, and therefore does not lead to significant itching/rash.
Another possibility is that PEP occurs from an immunologic response to circulating fetal antigens, as at least one study identified fetal male DNA in maternal skin lesions, and several other studies have documented a higher risk for PEP in women carrying males.
Under normal circumstances, a woman would reject a pregnancy since the embryo has different DNA than her own (includes the father); expression of a foreign “factor” that is different than someone else’s is known as an antigen, and causes an immune response to produce antibodies against it.
Management
Fortunately, PEP does not appear to affect the fetus and resolves relatively quickly. However, severe itching can be disabling, cause a loss of sleep, and affect a woman’s overall quality of life. Intense scratching can also worsen the rash, cause open wounds, and potentially lead to infection.
It is important women call their HCP anytime they have intense itching. HCPs will want to assess whether other conditions are present (ICP or Gestational Pemphigoid).
PEP cannot be diagnosed through lab work, and is normally a diagnosis of exclusion, or when other conditions have been ruled out. HCPs can help women manage the itch through lifestyle changes (see Action), and creams and certain medications, depending on the severity of the itching and scratching.
The primary goal of treatment in severe cases is to relieve itching and to reduce inflammation and redness in the skin. First-line treatments during pregnancy consist of topical or oral corticosteroids or antihistamines; these medications have good, short-term safety profiles.
Normally, the rash and itch resolve within 4 to 6 weeks from the time it begins, to include before delivery, or within 7 to 15 days after delivery. PEP does not normally result in any lasting issue or scarring with the skin.
Fluticasone propionate lotion is one of the newer types of topical corticosteroids with a low potential to cause adverse effects because of low systemic absorption and rapid metabolism and clearance; it is also U.S. Food and Drug Administration approved for use in infants as young as three months old for dermatitis.
Intramuscular injection of autologous whole blood (mother’s own blood) is also a potential option, but how it works to reduce symptoms is unclear, but it may help modulate the mother’s immune reactivity. AWB is being researched for a variety of immune-related conditions and further data may be necessary.
Action
It is important women call their HCP anytime they have intense itching during pregnancy so the HCP can perform an assessment and rule out other conditions. HCPs can also provide tips and management techniques to relieve itching.
Various creams and moisturizers may be able to provide temporary relief from itching and dry skin. Women should talk to their HCP before using any over-the-counter ointments for their itching.
While gentle scratching can temporarily relieve intense itching, women should be careful not to scratch too hard, which could break the skin, make the condition worse, and even lead to possible infection.
Women should also consider sharing their experience below regarding PEP or extreme itching during pregnancy. It can be comforting for women to hear from other women, as well as learning other management techniques for their itching, and what they should ask their HCP.
Partners/Support
Partners/Support can help women with skin-related changes during pregnancy by:
Helping her apply cream/lotion
Keeping her mind off any itching whenever possible and reminding her to avoid scratching too hard
Offering to change bed sheets if certain fabrics increase the sensation of itching
Gentle massaging, rubbing, or scratching her skin with the finger tips which could help her fall asleep
Providing positive emotional support when there is nothing the partner/support can do to help relieve her itching
Resources
Skin Conditions During Pregnancy (American College of Obstetricians and Gynecologists)
Polymorphic Eruption of Pregnancy (British Association of Dermatology)
Pruritic Urticarial Papules And Plaques Of Pregnancy (StatPearls/NCBI)