Chronic Urticaria in Pregnancy: Physiologic and Hormonal Background for an Immune Skin Disease

Abstract

Chronic urticaria (CU) is a cluster of manifestations specified as recurrent pruritic erythematous wheals or angioedema (AE), lasting for more than 6 weeks and complicating 1-2% of the population. Widespread presence of CU is higher in middle-aged women than men (1.3 vs 0.8%). It is proposed that this higher prevalence in women may be linked to female sex hormones, although the precise relationship between sex hormones and immune system function remains to be fully understood. Pregnancy is a condition that impacts CU activity in susceptible individuals. Likewise, CU can have effects on pregnancy, and conversely, pregnancy may alter the presentations of CU. Studies have shown Increased number of mast cells present in skin, and elevated serum levels of autoantibodies such as IgE anti-TPO, IgE anti-dsDNA, and IgE anti-IL-24 in chronic spontaneous urticaria (CSU) patients. The role of autoimmune diseases is crucial in these patients. Based on some evidence, immunologic tolerance is outside of the placenta milieu; and some other inflammatory conditions are alleviated during pregnancy. Chronic urticaria severity, medication before pregnancy, and AE before pregnancy were compromising factors leading to intensified urticaria in pregnancy. Managing CU in pregnant women presents unique challenges. There is little evidence about the safety and efficacy of medications in pregnant women with CU, and the cost/benefit of such treatments should be evaluated. Some studies recommend H1-antihistamines. Firstgeneration H1-antihistamines induce sleepiness and decreased attention by passing blood-brain barrier in CNS. However, second-generation H1-antihistamines have minimal CNS complication with most negligible side effects. Omalizumab, a biological monoclonal antibody against IgE molecules, is recently recommended by the guidelines as one of the therapeutic options in patients with uncontrolled CU. Cyclosporine and systemic corticosteroid are the other reserved options for the treatment of CU in pregnancy. In this review, we focused on the effect of underlying physiologic, hormonal, and immunologic changes during pregnancy over CU. Then assessed the noteworthy changes in the natural course of CU during pregnancy; the therapeutic challenges faced, and the complications associated with of CU and complications of CU during pregnancy.