Increased levels of estrogen that occur during pregnancy may be associated with improvement in psoriasis

Increased levels of estrogen that occur during pregnancy may be associated with improvement in psoriasis, according to a study in the May issue of Archives of Dermatology.

Anecdotal reports have suggested that psoriasis tends to improve during pregnancy, according to background information in the article. The current study investigated prospectively how psoriasis fluctuates in pregnancy and correlated progesterone and estrogen levels in pregnancy with psoriatic change.

Jenny E. Murase, M.D., of the University of California, Irvine, and colleagues compared changes over the course of one year in psoriatic body surface area in women with psoriasis in a group of 47 pregnant women and a control group of 27 non-pregnant pre-menopausal women. The women reported on their stress level, perceived psoriatic severity and the extent of their body surface affected by psoriasis five times over the course of the year: pregnant women at 10, 20 and 30 weeks gestation, and six and 24 weeks after birth and the control group at baseline, 10, 20, 36 and 54 weeks following enrollment. Hormone levels at each assessment were determined for 19 of the pregnant women.

During pregnancy, 55 percent of the patients reported improvement in psoriasis, 21 reported no change and 23 percent reported worsening. Only nine percent of patients reported improvement post partum, 26 reported no change and 65 percent reported worsening. Psoriatic body surface area decreased significantly from 10 to 20 weeks' gestation compared to controls and increased significantly six weeks post partum. Although 65 percent of the pregnant patients reported worsening, their psoriatic body surface area only returned to pre-pregnancy levels, the authors report. In pregnant women with 10 percent or greater psoriatic body surface area, lesions decreased by 83.8 percent during pregnancy. Psoriatic body surface area levels in the controls remained the same throughout the year.

"High level of estrogen correlated with improvement in psoriasis, whereas progesterone levels did not correlate with psoriatic change," the authors write. "We believe that further examination of how estrogen may improve psoriasis is warranted. Whether estriol [a form of estrogen] can improve psoriasis or can prevent worsening of psoriasis in menopause should be explored."