Patients with type I CSU typically exhibit elevated total IgE levels, allergic comorbidities, and rapid, robust responses to omalizumab, whereas those with type IIb CSU more often present with low IgE, positive autologous serum skin test or basophil activation assays, thyroid autoantibodies, eosinopenia, basopenia, and delayed or insufficient responses to anti-IgE therapy. This evidence concerns the gene IGHE and thyroiditis.