The Causes of Chronic Spontaneous Urticaria

Chronic Spontaneous Urticaria (CSU) presents as a heterogeneous disease requiring a shift from broad, uniform treatment to targeted, genotype-based therapy. Patients often fall into three distinct mechanisms: auto-allergy (Type 1), autoimmune-mediated (Type 2), or non-IgE-receptor-mediated (Type 3). While standard algorithms prioritize non-sedating antihistamines followed by omalizumab, emerging therapies like the BTK inhibitor remibrutinib offer faster response times for therapy-resistant cases. Diagnostic testing, including the chronic urticaria index, serves primarily to rule out mimics—such as occult infections or autoinflammatory syndromes—rather than to guide routine management. Although some practitioners utilize mycophenolate as a bridge therapy, clinical focus remains on identifying the underlying driver of mast cell activation. Integrating these insights allows for more precise, individualized treatment plans, moving beyond the limitations of traditional, trial-and-error approaches in dermatology.