Chronic urticaria and obstructive sleep apnea: Is there a significant association?

Background: Few studies have explored the association between obstructive sleep apnea (OSA) and chronic urticaria (CU). Our study aims to fill this gap by determining the frequency of the risk categories for OSA and how they might correlate with the specific CU patient reported outcome measures urticaria activity score (UAS7), urticaria control test (UCT) and CU quality of life questionnaire (CU-Q2oL). Methods: We conducted a cross-sectional study involving a cohort of 171 Latin American CU patients. Descriptive statistics were used to determine frequency and proportions for demographic and clinical variables, while a chi-squared test for association between STOP-Bang OSA questionnaire categories and both UAS7 and UCT categories was performed to analyze how such variables interact. To further assess the strength of the correlation a Cramer's V coefficient was reported. Finally, a Kendall-Tau b correlation coefficient was performed to measure the correlation between the STOP-Bang score and other independent continuous variables. Results: The average STOP-Bang score was 2.5, with 24% and 21% of patients falling into the intermediate and high-risk category for moderate-to-severe OSA, respectively. There was a strong statistically significant association (Cramer's V= 0.263; p=.000) between UAS-7 categories and STOP-Bang risk categories. A similar pattern of strong significant association (Cramer's V=.269; p=.002) was observed between UCT categories and STOP-Bang risk categories. A weak positive correlation between the STOP-Bang score and the CU-Q2oL average score (tau(b)=0.188, p=.001) was identified. Overall, 72.5% patients reported limitations with respect to sleep in a varied degree according to the CU-Q2oL. Conclusions: Our results suggest that a considerable proportion of patients with CU are at intermediate to high risk for OSA. Higher disease activity, poor CU control, and worse quality of life were all found to be associated with an increased risk. Additional studies are needed to determine the exact link between these conditions, and to determine whether screening and treatment for OSA might benefit patients with CU.