Polymorphic Eruption of Pregnancy 

Updated: Feb 21, 2020
Author: Joseph C Pierson, MD; Chief Editor: William D James, MD 

Overview

Background

Polymorphic eruption of pregnancy (PEP), first described as pruritic urticarial papules and plaques of pregnancy (PUPPP), refers to a benign dermatosis that usually arises late in the third trimester of a first pregnancy.[1, 2] The entity previously had been reported as toxemic rash of pregnancy,[3] toxemic erythema of pregnancy, and late-onset prurigo of pregnancy. See the image below.

Papules within prominent striae distensae. Courtes Papules within prominent striae distensae. Courtesy of Jeffrey P. Callen, MD of Louisville, Kentucky.

See Diagnosing Dermatoses in Pregnant Patients: 8 Cases to Test Your Skills, a Critical Images slideshow, for help identifying cutaneous eruptions associated with pregnancy.

Following atopic eruption of pregnancy, which occurs earlier in gestation, PEP is the second most common pruritic dermatosis of pregnancy.[4] (See DDx.) One European author proposes that early gestational papular dermatoses (usually atopic eruption of pregnancy) be referred to as "early-onset PEP," distinguished from "late-onset PEP".[5]

Epidemiology

Polymorphic eruption of pregnancy (PEP) occurs in 1 out of 160 pregnancies.[5, 6]  The condition may be less common in blacks.

Etiology

The cause and pathogenesis of polymorphic eruption of pregnancy (PEP) are not known. A meta-analysis revealed that 11.7% of patients with PEP had multiple gestation pregnancies.[7] Within that group, a higher PEP risk for triplet (14%) over twin (2.9%) pregnancies was found,[8] suggesting a relationship between skin distention and the development of PEP. Most studies have revealed increased maternal weight gain in patients with PEP when compared with normal pregnancies, further supporting the role of increased skin distention.[6, 9]

A study from Israel also found maternal hypertension and induction of labor to be significantly associated with the condition.[10] One large series[11] of cases revealed a male-to-female infant ratio of 2:1.

Investigators identified fetal deoxyribonucleic acid (DNA) in the skin of mothers with PEP, suggesting that chimerism may be relevant to the pathogenesis of this disorder.[12] Finally, a case-control study from France confirmed previously documented associations with multiple gestations, cesarean deliveries, and male fetuses, although no relationship to maternal or fetal weight gain was noted.[13]

Prognosis

The prognoses for the affected woman and her newborn are excellent in polymorphic eruption of pregnancy (PEP). It typically resolves within 4-6 weeks, independent of delivery,[6] and the condition does not tend to recur in subsequent pregnancies. Only 7% of multiparous PEP patients described a similar rash with prior pregnancies.[4] Patients who have had PEP will not precipitate a return of the condition through the subsequent use of oral contraceptives.

No mortality is associated with PEP. The mere appearance of an unusual skin eruption in pregnancy can provoke anxiety, but the pruritus is the most distressing feature. The later weeks of pregnancy can be associated with many physical symptoms, and the severe itching of PEP may further debilitate and aggravate sleep loss in the weeks prior to delivery. No known systemic complications exist for affected females, and fetal mortality or morbidity do not increase.

Patient Education

The patient should understand that PEP is a benign disorder and has not been shown to have adverse consequences for the fetus. Fully explain the side effects of corticosteroids and antihistamines (which are used in the treatment of PEP). Reassure the affected patient that PEP does not usually recur with subsequent pregnancies and will not be triggered by future use of oral contraceptives. (See Prognosis, Treatment, and Medication.)

 

Presentation

History

Polymorphic eruption of pregnancy (PEP) typically begins with intensely pruritic papules arising within striae distensae late in the third trimester of a first pregnancy. Of all cases, 73% are seen in primigravidae pregnancies.[4] Additionally, 11.7 % of affected females are multiple-gestation pregnancies.[7]

As many as 15% of PEP cases arise in the immediate postpartum period,[4] and in one case report 2 weeks postpartum.[14] In a few days, the eruption spreads to the buttocks and proximal thighs and may generalize. Patients present for a diagnosis of their unusual skin eruption and seek relief from the intense itching.

Physical Examination

In classic polymorphic eruption of pregnancy (PEP), papules occur within prominent striae distensae, as shown in the images below.

Papules within prominent striae distensae. Courtes Papules within prominent striae distensae. Courtesy of Jeffrey P. Callen, MD of Louisville, Kentucky.
Papules within prominent striae distensae. Courtes Papules within prominent striae distensae. Courtesy of Jeffrey P. Callen, MD of Louisville, Kentucky.

Similar lesions are often found on the buttocks and proximal thighs and may generalize elsewhere over the trunk and extremities, although the periumbilical area is characteristically spared. Small vesicles often are noted, but larger bullae, though documented in one case, typically do not occur and would suggest the possibility of pemphigoid gestationis.[15, 16] Less commonly, target lesions[17]  and annular and polycyclic wheals may be present. PEP usually does not affect the face, palms, or soles.

Although the eruption is intensely pruritic, excoriations rarely are found. One report described a case of PEP that progressed to involve the neck, arms, and legs in a photosensitive distribution as the initial abdominal involvement settled.[18]

 

DDx

Diagnostic Considerations

Conditions to consider in the differential diagnosis of polymorphic eruption of pregnancy (PEP) include the following:

  • Atopic eruption of pregnancy - Includes eczema of pregnancy, prurigo of pregnancy, pruritic folliculitis of pregnancy

  • Pemphigoid gestationis (herpes gestationis)[19]

  • Intrahepatic cholestasis of pregnancy

  • Impetigo herpetiformis

  • Viral exanthem

  • Scabies - Check for scabies if the history and physical examination findings are suggestive

  • Anaplastic large cell lymphoma - Consider this in a pregnant patient who presents with cutaneous symptoms[20]

Differential Diagnoses

 

Workup

Approach Considerations

Lab studies

No blood or urine laboratory tests are diagnostic of polymorphic eruption of pregnancy (PEP) and are not typically performed. One large series of cases showed a significant reduction of serum cortisol levels in patients with PEP compared with normal pregnant controls.[11]

Serum submitted for indirect immunofluorescence or NC16a enzyme-linked immunosorbent assay may help to differentiate between PEP and pemphigoid gestationis when the clinical diagnosis is unclear.[21] Both studies detect autoantibodies that are present in persons with pemphigoid gestationis but are not present in those with PEP.

Direct immunofluorescence

In punch biopsy specimens of the skin, direct immunofluorescence (DIF) characteristically is negative in PEP. DIF results differentiate PEP from pemphigoid gestationis when the clinical diagnosis is unclear. The latter disorder is a rare, autoimmune blistering disease characterized by linear deposits of C3 along the basement membrane zone.

Histologic findings

Skin biopsy is rarely necessary. Routine biopsy specimens from PEP usually reveal a normal epidermis, but focal spongiosis and parakeratosis may be seen. Within the papillary dermis and mid dermis, a lymphohistiocytic infiltrate with a variable number of eosinophils and dermal edema is present.[22]

 

Treatment

Approach Considerations

Treatment is directed at relieving the pruritus associated with polymorphic eruption of pregnancy (PEP). Topical corticosteroids are the mainstay of treatment.[23] High-potency topical (class I or II), or even systemic, steroids may be required to alleviate symptoms. Oral antihistamines are only mildly effective.

General treatment measures include the use of cool, soothing baths; emollients; wet soaks; and light cotton clothing. PEP tends to resolve spontaneously shortly after delivery. Morbidity is not increased for the fetus born to an affected mother. An older case report described early cesarean delivery to relieve a severe case of PEP.[24]

For patients who strive to avoid the use of any medications when pregnant or breastfeeding, PEP has been successfully treated with intramuscular injection of autologous whole blood in three cases.[25]

PEP typically resolve within 4-6 weeks, independent of delivery.[6] Continue symptomatic care until resolution.

Consultations

The healthcare provider responsible for the patient's obstetric care should be made aware of the diagnosis, treatment, and favorable prognosis of PEP.

 

Medication

Medication Summary

As previously mentioned, topical corticosteroids are the mainstay of treatment for polymorphic eruption of pregnancy (PEP).[23] Symptom alleviation may require high-potency topical (class I or II) steroids, such as fluocinonide, or even systemic steroids. Oral antihistamines are only mildly effective.

Diphenhydramine, an antihistamine, has a sedative effect that may help patients to sleep better; it is also an effective agent against pruritus resulting from histamine release during inflammatory reactions.

Medications may need to be used into the postpartum period. Pay attention to potential adverse effects with breastfeeding.

Corticosteroids

Class Summary

Corticosteroids have anti-inflammatory properties and cause profound and varied metabolic effects. In addition, these agents modify the body's immune response to diverse stimuli. Use systemic steroids for severe, refractory cases only.

Fluocinonide (Vanos)

Fluocinonide is a class II, high-potency, topical corticosteroid that inhibits cell proliferation. It is immunosuppressive and anti-inflammatory.

Fluticasone (Cutivate)

Fluticasone is a high-potency, topical corticosteroid that inhibits cell proliferation. It is immunosuppressive and anti-inflammatory.

Prednisone

Prednisone may decrease inflammation by reversing increased capillary permeability and suppressing polymorphonuclear leukocyte activity.

Prednisolone (Pediapred, Orapred, Flo-Pred)

This glucocorticosteroid occurs naturally and synthetically. It is used for both acute and chronic asthma. It may decrease inflammation by reversing increased capillary permeability and suppressing polymorphonuclear leukocyte activity.

Antihistamines, 1st Generation

Class Summary

Antihistamines have a sedative effect that may improve sleep.

Diphenhydramine (Benadryl, Diphenhist, Allerdryl)

Diphenhydramine is used for the symptomatic relief of pruritus caused by the release of histamine in inflammatory reactions.

Hydroxyzine (Vistaril)

Hydroxyzine antagonizes H1 receptors in the periphery. It may suppress histamine activity and subsequently cause relieve of pruritus.

 

Questions & Answers

Overview

What is polymorphic eruption of pregnancy (PEP)?

What is the prevalence of polymorphic eruption of pregnancy (PEP)?

What causes polymorphic eruption of pregnancy (PEP)?

What is the prognosis of polymorphic eruption of pregnancy (PEP)?

What is included in patient education about polymorphic eruption of pregnancy (PEP)?

Presentation

Which clinical history findings are characteristic of polymorphic eruption of pregnancy (PEP)?

Which physical findings are characteristic of polymorphic eruption of pregnancy (PEP)?

DDX

Which conditions should be considered in the differential diagnoses of polymorphic eruption of pregnancy (PEP)?

What are the differential diagnoses for Polymorphic Eruption of Pregnancy?

Workup

What is the role of lab testing in the diagnosis of polymorphic eruption of pregnancy (PEP)?

What is the role of DIF in the diagnosis of polymorphic eruption of pregnancy (PEP)?

Which histologic findings are characteristic of polymorphic eruption of pregnancy (PEP)?

Treatment

How is polymorphic eruption of pregnancy (PEP) treated?

Which specialist consultations are beneficial to patients with polymorphic eruption of pregnancy (PEP)?

Medications

Which medications are used in the treatment of polymorphic eruption of pregnancy (PEP)?

Which medications in the drug class Antihistamines, 1st Generation are used in the treatment of Polymorphic Eruption of Pregnancy?

Which medications in the drug class Corticosteroids are used in the treatment of Polymorphic Eruption of Pregnancy?