Psoriasis is a cutaneous immune-mediated disease which tends to improve during pregnancy
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This article reviews the immunologic mechanisms that may contribute to this improvement.
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We hope to encourage the development of new and inexpensive topical or oral treatment for psoriasis in women of childbearing age.
Abstract
Background
Immunological changes in pregnancy are associated with improvements in some pre-existing immune-mediated skin diseases. Estrogen has been hypothesized to contribute to these changes by creating a shift from Th1 and Th17 to Th2 immunity. As this hypothesis would predict, psoriasis (a primarily Th17 mediated immune disease) tends to improve during pregnancy. However, the precise mechanism by which estrogen induces immunological change in psoriasis remains poorly understood.
Objective
To summarize the immunologic effects of estrogen as they relate to psoriasis during pregnancy.
Methods
We performed an English-language PubMed search of articles from September 2004 to September 2014 combining the key terms "psoriasis," "estrogen," "autoimmune disease," and "pregnancy."
Results
Estrogen appears to up-regulate Th2 cytokines and down-regulate Th1 and Th17 cytokines. This shift was initially observed in murine systems, which showed decreased mixed lymphocyte reactions of splenocytes and increased antibody production during pregnancy. Antigen stimulated splenocytes produced fewer Th1 cytokines and more Th2 cytokines in pregnant mice. IL17 producing T cells were significantly decreased in healthy pregnancies compared to non-pregnant controls.
Limitations
This review is limited by the paucity of studies evaluating immunological changes of psoriasis in pregnancy among human subjects.
Conclusions
Increased estrogen production in pregnancy is associated with decreased Th1 and Th17 cytokine production. While estrogen may be responsible for some of these immune shifts resulting in disease improvement, there remains no definitive evidence to prove the hypothesis that estrogen is responsible for such improvement.