A recent study involved a comprehensive search of the available literature and reviews undertaken to analyze articles reporting pre-existing chronic skin disorders in pregnant women, with the purpose of assimilating the current knowledge on their particular clinical and therapeutic aspects.

The findings depicted that pregnancy is characterized by a decrease in cell-mediated maternal immunity (Th1-mediated) and the predominance of humoral immunity (Th2-mediated). This estrogenic-driven shift of the immune system may explain the remission of psoriasis and other inflammatory disorders, and flare of AD. Meanwhile, hidradenitis suppurativa (HS) may improve during pregnancy; which could also occur due to a hormonal-driven decrease of apocrine gland activity. Whereas, acne vulgaris may worsen, probably from the increased androgen levels.

The current literature points towards an improving trend for the clinical course of psoriasis during pregnancy. However, the risk of flares increases slightly post-delivery. Remission of psoriasis during pregnancy is thought to primarily result from physiological maternal switch to an adaptive Th2 response. 

For patients who experience and exacerbation of psoriasis symptoms, low- to mid-potency topical corticosteroids should be given in the first-line, for mild forms, and narrow-band ultraviolet (NB-UVB) phototherapy is advised as the second-line option.While in severe psoriasis, cyclosporine and biologics may be considered as third-line options, after weighing the risk-benefit ratio. 

Certolizumab – approved for psoriatic arthritis, has the most negligible rate of placental transfer. In mothers and infants who receive biologics, live vaccination must be avoided for 6 months following delivery. 

Impetigo herpetiformis – a rare form of generalized acute pustular psoriasis, which is trigerred during pregnancy, requires strict monitoring as its clinical course may lead to maternal or fetal mortality. It may recur in subsequent pregnancies as well.

Source: Dermatology. 2021;237:771–785. Doi: 10.1159/000509726