Among the first group (anti-TPO IgE at any point), we identified 3 subgroups: patients with anti-TPO IgE during the clinical control period (n = 12); patients with anti-TPO IgE during the clinical control period and significantly increased levels during an urticaria exacerbation (n = 18); and patients with anti-TPO IgE only during an exacerbation (n = 13). Here, IGHE is linked to urticaria.