Risk Factors And Diagnostic Value Of Cough Variant Asthma In Children

Objective:To investigate the risk factors associated with cough variant asthma(CVA)in children and the clinical tests indicators that having diagnostic value,and to improve the early identification of CVA.Methods:According to the inclusion and exclusion criteria,81 children with chronic cough who visited the pediatric outpatient clinic of Shanxi Bethune Hospital from October 2021 to October 2022 were selected.According to the diagnostic criteria and diagnostic treatment results,they were divided into CVA group(29 cases)and non-CVA group(52cases).The medical history including gender,eczema history,allergy history,family history of allergic diseases and cough characteristics were collected,and related clinical test indicators including fractional concentration of exhaled nitric oxide(FeNO),peripheral blood eosinophils count(AEC)and percentage(sEOS%)and serum total IgE level were collected.The data of the two groups were analyzed retrospectively.Results:1.There were significant differences between the two groups in gender,eczema history,allergy history,family history of allergic diseases and cough characteristics(P<0.05).Fractional concentration of exhaled nitric oxide(FeNO),absolute eosinophils count(AEC)and percentage(sEOS%),and serum total IgE level in the CVA group were higher than those in the non-CVA group(P<0.05).2.There was a significant linear positive correlation between FeNO level and AEC,sEOS%,IgE(r=0.552,r=0.585,r=0.522.all P<0.001).3.Binary Logistic regression analysis showed that family history of allergic disease,IgE and FeNO lever were independent risk factors for CVA(P<0.05).The area under curve for FeNO diagnosing CVA was 0.899,and the sensitivity and specificity were82.8% and 84.6% when the optimal cut-off value was 18.65ppb(P<0.05).The AUC of FeNO combined with IgE in the diagnosis of CVA was 0.912,the sensitivity was 82.8%,and the specificity was 92.3%(P<0.05).Conclusion:Eosinophils(EOS)inflammation and IgE are involved in the occurrence and development of CVA.FeNO can more directly reflect the airway allergy of CVA and EOS inflammation.Family history of allergic diseases and elevated levels of IgE and FeNO are independent risk factors for CVA.The diagnostic efficacy of single index FeNO is better than that of AEC,sEOS% and IgE in the diagnosis of CVA.The combination of the two indexes can improve the positive predictive value of CVA diagnosis.