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Pruritic urticarial papules and
plaques of pregnancy
The eruption appears suddenly in the third trimester. Red papules begin, in 90% of cases, in the striae of the abdomen.
Lesions rapidly spread to the abdomen and increase in number. Itching is moderate to intense, but there are no excoriations.
Lesions spread to the thighs, buttocks, chest, and upper arms. They can be urticarial, vesicular, or target-like, and resemble erythema multiforme.
Extensive eruption involving the entire trunk, upper arm, and buttock. The eruption rapidly cleared within 1 week of delivery.
DESCRIPTION
Pruritic urticarial papules and plaques of pregnancy (PUPPP) is the most common dermatosis of pregnancy. It affects between 1 in 300 pregnant women. Most cases show pruritic hive-like lesions on the abdomen. The urticarial lesions of herpes gestationis may be confused with PUPPP lesions. Direct immunofluorescence skin biopsy can help differentiate the two diseases. There are no immunofluorescence findings with PUPPP. Herpes gestationis shows C3 with or without IgG in a linear band along the basement membrane zone.
HISTORY
• PUPPP occurs primarily in primigravidas in the third trimester. It can occur in the postpartum period. • Mean duration is 6 weeks. • Itching is moderate to intense. Intense itching lasts about 1 week. • The eruption typically clears within 1 week of delivery. • There are no fetal or maternal complications. • Infants do not develop the eruption. • Recurrence in subsequent pregnancies or with oral contraceptives is unusual.
PHYSICAL FINDINGS
• Lesions usually first appear in the striae on the abdomen. They begin as red papules surrounded by a pale halo but rapidly evolve to urticarial papules. • Vesicles and erythema multiforme-like target lesions may resemble the lesions of herpes gestationis. • The rash spreads in a few days to the thighs, buttocks, chest, and upper arms. It spares the face, palms, and soles. Most lesions consist of either papules or hive-like plaques.
TREATMENT
• Treatment is supportive. • Antipruritic topical lotions containing menthol (Sarna lotion) are soothing. • Medium-potency topical steroids (e.g. triamcinolone cream 0.1%) suppress inflammation. • Antihistamines such as fexofenadine (Allegra) control itching. • A short course of oral prednisone can be safely prescribed for severe cases. • Ultraviolet B is reported to be effective.
