Abstract: 【Abstract】 Objective To analyze clinical data from patients with chronic spontaneous urticaria （CSU）, and to explore their disease burden. Methods Clinical data were retrospectively collected from CSU outpatients who visited the Tianjin Medical University General Hospital from November 2021 to October 2023. The primary evaluation indicators included the 7-day urticaria activity score （UAS7） , chronic urticaria quality of life questionnaire （CU-Q2oL）, urticaria control test （UCT）, medication use in the past 6 months, number of outpatient visits and medical expenses, CSU disease duration, and the presence of comorbid atopic diseases and autoimmune diseases. For quantitative data, results were expressed as mean ± standard deviation when normally distributed, or as median （lower quartile, upper quartile） when not normally distributed. Correlation analysis was performed using Pearson correlation coefficients, false discovery rate （FDR） correction, multivariate linear regression, and collinearity diagnostics. Results A total of 489 CSU patients were included, comprising 303 females （62.0%） and 186 males （38.0%）, with the ages being 39.3 ± 15.0 years and disease duration being 0.75 （0.17, 3） years. The number of outpatient visits was 5.1 ± 1.9, and the medical costs were 396.4 ± 116.0 yuan. Baseline UAS7, UCT, and CU-Q2oL scores were 16.9 ± 11.0 points, 7.0 ± 3.8 points, and 51.9 ± 16.3 points, respectively. Seventy-two patients （14.7%） had a family history of atopic diseases, and 144 patients （29.4%） had comorbid atopic conditions, including atopic dermatitis （n = 29）, allergic rhinitis （n = 89）, allergic conjunctivitis （n = 13）, allergic asthma （n = 7）, and allergic sinusitis （n = 6）. Forty-one patients （8.4%） had comorbid autoimmune diseases, including connective tissue diseases （n = 2） and autoimmune thyroid diseases （n = 39）. In the past 6 months, 419 patients （85.7%） received first-line or second-line therapies （antihistamines alone or in combination）, while 70 patients （14.3%） received third-line therapies, including omalizumab （n = 35, 7.1%）, glucocorticoids （n = 22, 4.5%）, cyclosporine （n = 7, 1.4%）, and Tripterygium wilfordii preparations （n = 7, 1.4%）. According to the UAS7 scores, 98 patients （20.0%） were in good control, 153 （31.3%） exhibited mild disease activity, 138 （28.2%） showed moderate activity, and 100 （20.5%） exhibited severe activity; outpatient visits and medical costs increased with disease activity （both P < 0.05）. The CU-Q2oL scores were positively correlated with the UAS7 scores （r = 0.520, P < 0.001, FDR < 0.001）, and negatively correlated with the UCT scores （r = -0.597, P < 0.001, FDR < 0.001）. Disease duration was positively associated with the UAS7 scores （β = 0.223, P = 0.023）. The patients with autoimmune diseases had significantly longer disease duration （P = 0.049）, but there was no significant difference in the UAS7 score between the patients with and without autoimmune diseases （P = 0.340）; there were no significant differences in disease duration or UAS7 scores between patients with and without atopic diseases （both P > 0.05）. Conclusion Higher disease activity in CSU patients was significantly correlated with worse quality of life, increased outpatient visits, and greater economic burden.

Key words: Chronic urticaria, Cost of illness, Chronic spontaneous urticaria, 7-day urticaria activity score, Chronic urticaria quality of life questionnaire, Urticaria control test