ABSTRACT Background No validated tools exist to evaluate chronic urticaria (CU) control in children. While the Urticaria Control Test (UCT) exhibits favourable clinometric properties in adult CU, it is not yet validated in children. Therefore, we sought to evaluate the validity of the UCT for the assessment of pediatric CU. Methods Children presenting with CU were consecutively recruited. Participants completed both the UCT and the Children’s Dermatology Life Quality Index (CDLQI). We assessed the internal consistency, convergent and known-groups validity, and screening accuracy of the UCT at study entry and at follow-up. Results A total of 52 children with CU were recruited. The UCT exhibited respectable internal consistency in the evaluation of CU (Cronbach’s α=0.73 [95%CI: 0.62, 0.85]). UCT and CDLQI scores strongly correlated (r=-0.74, P<0.01). The UCT distinguished between different strata of disease severities established by the CDLQI (P<0.01). Screening accuracy of the UCT was excellent in the discrimination of poorly controlled CU (area under the curve=0.82). An optimal cut-off of ≤10 was determined for defining poorly controlled CU (sensitivity=95.5%, specificity=63.3%). Data at follow-up were consistent with data at study entry. Conclusion The UCT is a valid tool for the assessment of pediatric CU and CSU, as evidenced by acceptable internal consistency, convergent and known-groups validity, and screening accuracy at multiple time points.

Background Cold urticaria (coldU) is associated with substantial morbidity and risk of fatality. Data on coldU in children are sparse. We aimed to evaluate the clinical characteristics, management, risk of associated anaphylaxis, and resolution rate of coldU in a pediatric cohort. Additionally, we sought to compare these metrics to children with chronic spontaneous urticaria (CSU). Methods We prospectively enrolled children with coldU from 2013-2021 in a cohort study at the Montreal Children’s Hospital and an affiliated allergy clinic. Data for comparison with participants with solely CSU were extracted from a previous study. Data on demographics, comorbidities, severity of presentation, management, and laboratory values were collected at study entry. Patients were contacted yearly to assess for resolution. Results Fifty-two children with cold urticaria were recruited, 51.9% were female and the median age of symptom onset was 9.5 years. Most patients were managed with second generation H1-antihistamines (sgAHs). Well-controlled disease on sgAHs was negatively associated with concomitant CSU (adjusted odds ratio (aOR)=0.69 [95%CI: 0.53, 0.92]). Elevated eosinophils were associated with cold-induced anaphylaxis (coldA) (aOR=1.38 [95%CI: 1.04, 1.83]), which occurred in 17.3% of patients. The resolution rate of coldU was 4.8 per 100 patient-years, which was lower than that of CSU (adjusted hazard ratio=0.43 [95%CI: 0.21, 0.89], P<10-2). Conclusion Pediatric coldU bears a substantial risk of anaphylaxis and a low resolution rate. Absolute eosinophil count and co-existing CSU may be useful predictive factors.