Targeting immune dysregulation in chronic spontaneous urticaria: beyond antihistamines

Chronic urticaria (CU) is characterized by recurrent wheals and angioedema lasting longer than six weeks. It affects approximately 0.5-1.4% of the population and profoundly impairs the quality of life. The disease exhibits a variable course, with many patients experiencing symptoms for several years. Higher disease activity correlates with increased burden and delayed remission. Therefore, early and effective intervention is critical to improving patient outcomes. Current first-line therapies target histamine, the principal effector mediator released from activated mast cells, using non-sedating H1-antihistamines. However, mast cells secrete a wide array of additional mediators, including platelet-activating factor, leukotrienes, cytokines, and neuropeptides, all of which contribute to vasodilation, pruritus, and inflammatory cell recruitment. Therapies targeting these mediators provide adjunctive benefits but remain insufficient because they do not prevent mast cell activation. This limitation has prompted a paradigm shift toward upstream strategies designed to inhibit mast cell activation and degranulation. These strategies can be broadly divided into IgE-dependent approaches, targeting the cross-linking of the high-affinity IgE receptor, which include anti-IgE monoclonal antibodies, IgE traps, and Bruton's tyrosine kinase inhibitors, and non-IgE-mediated approaches, such as cytokine blockade (interleukin [IL]-4, IL-5, IL-17, and IL-33), complement inhibition, c-kit targeting, Siglec-8 modulation, MRGPRX2 antagonism, and alarmin-directed therapies. Collectively, these advances signify a shift in chronic spontaneous urticaria (CSU) management from symptomatic mediator blockade to mechanism-based and personalized therapy. The ultimate objective is not merely to control symptoms but also to achieve true disease modification by altering the natural course of CSU.