Prevalence and associated factors of airway hyper- responsiveness in children with recurrent chronic cough

Abstract

Background Airway hyper-responsiveness (AH) is a common char- acteristic of asthma. Patient who has recurrent chronic cough with AH is commonly referred as “cough variant asthma”. Histamine provocation test should be performed to determine whether a pa- tient has “cough variant asthma” or recurrent viral bronchitis. Objective To determine AH prevalence in children with recurrent chronic cough and factors associated with it. Methods A cross sectional study was conducted on 6-12 year-old children with recurrent chronic cough at the Pediatrics Outpatient Clinic, Sanglah Hospital Denpasar from September 2002 until June 2003 Results Twenty one out of 64 (33%) subjects suffering from recur- rent chronic cough without wheezing had AH. Associated factors significantly associated with AH were age, allergic rhinitis, pater- nal and maternal history of atopy, passive smoking, use of mos- quito-coil, positive skin prick test, and eosinophilia. Spearman cor- relation analysis between associated factors and AH showed that positive skin prick test and passive smoking were moderately cor- related with AH (r=0.56, p<0.0001; r=0.57, p<0.0001, respectively), whereas multivariate regression logistic analysis on associated factors found true associated factors, such as positive skin prick test (p=0.01; OR=14.82), history of atopy in father (p=0.02; OR=22.75), and passive smoking (p=0.03; OR=11.97). Conclusions The prevalence of airway hyper-responsiveness in children with recurrent chronic cough without history of wheezing was 33%. Independent associated factors of AH in recurrent chronic cough children are positive skin prick test, history of atopy in fa- ther, and passive smoking

Keywords

• airway hyper-responsiveness
• recurrent chronic cough
• histamine provocation test
• prick test
• atopy
• passive smoking
• cough variant asthma