Question

Discussion

The answer is E: pruritic urticarial papules and plaques of pregnancy (PUPPP). The most common pregnancy-specific dermatosis, PUPPP is estimated to affect one in 160 to 300 pregnancies.¹ Although the etiology is unknown, skin damage secondary to abdominal distention in pregnancy may play a role.²

PUPPP typically occurs in primiparous women late in the third trimester. PUPPP-associated lesions present as multiple polymorphic, edematous, nonfollicular, erythematous papules and vesicles that coalesce into plaques. Initial lesions are insidious, occurring on the abdominal striae, and may spread within days. The lesions often spare the umbilicus, face, palms of the hands, and soles of the feet and usually are intensely pruritic. Routine laboratory testing shows no abnormalities. Skin biopsy is often nonspecific with findings that resemble urticaria with varying degrees of dermal edema.

Common treatments for PUPPP include potent topical steroids and oral antihistamines to control the lesions and pruritus.³ Systemic corticosteroids may be required in severe cases. The lesions typically resolve within a few weeks of delivery, and no fetal harm has been shown.

Cholestasis of pregnancy is an idiopathic condition that occurs in the third trimester. Patients commonly present with intense pruritus without associated skin lesions. Patients may appear jaundiced and have elevated serum bile acids, including cholic, deoxycholic, and chenodeoxycholic acids.¹ Pruritus usually resolves spontaneously after delivery, but recurrence in subsequent pregnancies is likely. There is an increased risk of meconium staining and preterm labor.⁴

Pemphigoid gestationis is an antibody-mediated auto-immune dermatosis of pregnancy. It is also called herpes gestationis, although it is not caused by herpesvirus infection. The incidence is estimated to be one in 50,000 pregnancies.³ The condition typically presents late in pregnancy as intensely pruritic, centrally crusted papules that initially occur on the abdomen. Lesions tend to spread quickly, sparing the face, mucous membranes, palms of the hands, and soles of the feet. Patients may experience multiple flare-ups and remissions. Routine laboratory tests are normal, but direct immunofluorescence staining shows linear complement 3 with or without immunoglobulin G deposition along the dermo-epidermal junction.⁵ Lesions usually resolve spontaneously within weeks of delivery, but recurrence is common with subsequent pregnancies.

Prurigo gestationis is a poorly understood dermatosis of unknown etiology. The incidence is about one in 300 pregnancies. Patients often present with multiple discrete, excoriated papules on extensor surfaces during the second and third trimesters. Laboratory tests are normal, and immunofluorescence staining is negative. The lesions may last for weeks to months postpartum, and recurrence in subsequent pregnancies is likely. No fetal harm has been demonstrated.

Pruritic folliculitis of pregnancy typically presents as multiple disseminated, erythematous, excoriated papules initially occurring on the trunk and then spreading to the extremities. In contrast to PUPPP-associated lesions, which often originate over abdominal striae, these lesions are folliculocentric. The lesions resolve spontaneously within weeks of delivery.