The Urticaria Severity Score: a sensitive questionnaire/index for monitoring response to therapy in patients with chronic urticaria.

Background: Despite the existence of numerous dermatology-specific quality-of-life questionnaires, there exists a need for a well-validated instrument to evaluate and monitor patients with chronic urticaria.
Objective: To develop and validate a novel chronic urticaria-specific questionnaire, the Urticaria Severity Score (USS).
Methods: The USS was developed with 12 questions and 7 response options per question included in the final questionnaire. The USS was pilot tested on 28 patients with symptomatic chronic urticaria, and a modified version was tested in 80 patients. In this latter group, the USS was compared with the previously validated Dermatology Life Quality Index (DLQI). Patients completed both questionnaires at baseline and at follow-up (median, 2 weeks). Spearman rank correlation tests were used to compare the USS with the DLQI. At a subsequent visit, 9 additional patients completed the USS to evaluate test-retest reliability.
Results: There was a positive correlation between the USS and DLQI at baseline (r = 0.64) and follow-up (r = 0.69). The test-retest reliability correlation for the USS was adequate (r = 0.96) (P = .001). The USS was more sensitive in detecting symptom improvement than the DLQI. The mean (SD) "raw score" change from baseline to follow-up for the USS was 9.95 (12.80), whereas the mean (SD) change from baseline to follow-up for the DLQI was 2.25 (4.87).
Conclusions: The USS is a valid and reliable instrument for monitoring urticaria severity. The USS is more sensitive than the DLQI for quantifying urticaria severity and may be moreapplicable in the evaluation of urticaria-specific treatment efficacy.