BACKGROUND: Chronic spontaneous urticaria (CSU), a disease predominantly affecting females, has limited information available on its differences between females and males of varying ages.

OBJECTIVES: To investigate sex differences in age groups regarding disease activity, comorbidities, quality of life (QoL) and treatment patterns in CSU patients.

METHODS: We analysed Chronic Urticaria Registry (CURE) data, an international real-world registry for patients with chronic urticaria. Patients were recruited via an online platform using a standardized questionnaire. The data were analysed for demographics, age of onset, duration of urticaria, (Urticaria Activity Score [UAS], Urticaria Control Test [UCT], Chronic Urticaria Quality of Life Questionnaire [CU-Q2oL]), family history, systemic symptoms, aggravating factors, comorbidities, smoking and alcohol consumption, laboratory parameters, burden of disease, treatment distribution and response rates, compliance to treatment and adverse events. Comparisons were made among age groups <13, 13-17, 18-30, 31-50, 51-65 and >65 years.

RESULTS: Across 4136 CSU patients (from 58 sites across 29 countries), 2994 (72.4%) were female. Statistically significant female predominance started at age 31 (<0.001). Compared with males, females showed higher rates of angioedema (59.6 vs. 51.7%; p < 0.001), systemic symptoms (34.6 vs. 25.4%; p < 0.001), sleep disturbance (38.9 vs. 32.5%; p < 0.001), QoL impairment (CU-Q2oL score 32 vs. 27.7; p < 0.001) and lower rates of urticaria control than males in all medication categories (p < 0.05 for all). Females had more concomitant diseases, including asthma, thyroid disease, obesity, autoimmune disease, gastrointestinal disease and depression (p < 0.05 for all). The disease was especially more burdensome and refractory in females aged 51-65 years than males, evidenced by more angioedema and systemic symptoms, worse QoL, lower UCT scores and more emergency visits (p < 0.05 for all). However, these differences were not prominent in the elderly females (>65 years).

CONCLUSIONS: Compared with males, female CSU patients experience more burdensome disease, which gets worse in midlife.

CLINICALTRIALS: gov (or equivalent) listing (if applicable None).