Merck Manual

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Polymorphic Eruption of Pregnancy

(Pruritic Urticarial Papules and Plaques of Pregnancy; PUPPP)


Antonette T. Dulay

, MD, Main Line Health System

Reviewed/Revised Oct 2022 | Modified Nov 2022

Polymorphic eruption of pregnancy is benign pruritic skin eruptions of unknown cause that develop during pregnancy.

Most cases of polymorphic eruption of pregnancy occur during a first pregnancy. Overall incidence is 1/160 to 300 pregnancies; however, with multiple gestation, risk is 8 to 12 times higher.

Symptoms and Signs

Lesions are intensely itchy, erythematous, solid, superficial, and elevated; some are surrounded by blanching, and some have minute vesicles in the center. Itching keeps most patients awake, but excoriation is uncommon. Lesions begin on the abdomen, frequently on striae atrophicae (stretch marks), and spread to the thighs, buttocks, and occasionally the arms. The palms, soles, and face are usually spared. Most patients have hundreds of lesions.

Lesions develop during the 3rd trimester, most often in the last 2 to 3 weeks and occasionally in the last few days or postpartum. They usually resolve within 15 days after delivery but can take longer. They may recur in up to 5% of subsequent pregnancies.


  • Skin examination

Polymorphic eruption of pregnancy is diagnosed by examining the skin. Differentiation from other pruritic eruptions may be difficult. Early lesions of polymorphic eruption of pregnancy usually start in striae on the abdomen; in pemphigoid gestationis, early lesions are usually periumbilical.


  • Corticosteroids

  • Nonsedating oral antihistamines

  • Supportive care

Mild symptoms are treated with topical corticosteroids (eg, 0.1% triamcinolone acetonide cream up to 2 or 3 times a day). Rarely, more severe symptoms require systemic corticosteroids (eg, prednisone 40 mg orally once a day, tapered as tolerated). Short courses of systemic corticosteroids given late in pregnancy do not seem to have adverse effects on the fetus.

Nonsedating oral antihistamines can also be used to relieve pruritus.

Key Points

  • Polymorphic eruption of pregnancy consists of intensely itchy skin lesions that usually develop during the last 2 to 3 weeks of pregnancy and resolve within 15 days after delivery.

  • Differentiating these lesions from others pruritic eruptions may be difficult.

  • Treat with topical corticosteroids for mild symptoms and oral corticosteroids for more severe symptoms.

Drugs Mentioned In This Article

Drug Name Select Trade
Aristocort, Aristocort A, Aristocort Forte, Aristocort HP, Aristo-Pak, Aristospan, Azmacort, Children's Nasacort Allergy 24HR Nasal Spray, Cinalog, Cinolar, Flutex, Hexatrione, Kenalog, Kenalog in Orabase, Kenalog-10, Kenalog-40, Kenalog-80, Nasacort, Nasacort AQ, Oralone, SP Rx 228 , Tac-3 , Triacet , Triamonide , Trianex , Triderm , Triesence, XIPERE, Zilretta
Deltasone, Predone, RAYOS, Sterapred, Sterapred DS
NOTE: This is the Professional Version. CONSUMERS: View Consumer Version
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