Epidemiology of Polymorphic Eruption of Pregnancy

Some of our assumptions about this condition have been mistaken.

An eruption occurring in the third trimester of pregnancy, primarily in primigravid women, was first described in 1979 and given the designation pruritic urticarial papules and plaques of pregnancy (PUPPP). Later investigation linked the syndrome to twin pregnancies and excessive weight gain. Several subsequent studies found greater frequency when the fetus was male, but one other study found greater frequency with female fetal sex. Researchers have suggested that all eruptions of pregnancy be categorized together as polymorphic eruption of pregnancy (PEP).

These authors performed a retrospective, case-control study of 200 pregnancies: 40 women with PEP and 4 matched healthy controls each. The researchers noted a number of factors that were statistically associated with PEP in univariate analysis, including primigravidas, multiple-gestation pregnancy, maternal weight gain, male fetal sex, cesarean delivery, and hospitalization. In multivariate analysis, however, only male fetal sex, cesarean delivery, and hospitalization remained statistically significant. The authors did not have the data to analyze the risk for recurrence in these patients.

Comment: PUPPP or PEP does not occur only in primigravid women; it does not always occur in the third trimester of pregnancy and does not appear to be related to maternal weight gain. This condition appears to be more frequent in pregnancies with male fetuses and may yet prove to be related to multiple-gestation pregnancy. Patients with this disorder also have more-frequent cesarean delivery and more-frequent hospitalization. We wonder whether our standing belief that this disorder does not recur may soon be disproved.

— Jeffrey P. Callen, MD

Published in Journal Watch Dermatology February 8, 2008

Citation(s):
Regnier S et al. A case-control study of polymorphic eruption of pregnancy. J Am Acad Dermatol 2008 Jan; 58:63.