Pruritic Urticarial Papules and Plaques of Pregnancy
Pruritic urticarial papules and plaques of pregnancy are pruritic eruptions of unknown cause that develop during pregnancy.
Most cases occur during a first pregnancy. Overall incidence is 1/160 to 300 pregnancies; however, with multiple gestation, risk is 8 to 12 times higher.
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 wk 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.
Mild symptoms are treated with topical corticosteroids (eg, 0.1% triamcinolone acetonide cream up to 6 times/day). Rarely, more severe symptoms require systemic corticosteroids (eg, prednisone 40 mg po once/day, tapered as tolerated). Short courses of systemic corticosteroids given late in pregnancy do not seem to have adverse effects on the fetus.