Airway anomalies in flexible bronchoscopy for pediatric chronic cough: predictive value of specific clinical symptoms

Chronic cough, defined as cough lasting more than four weeks in children, is a frequent reason for pediatric pulmonology referrals. The underlying etiology often remains unclear despite extensive non-invasive evaluations, thus necessitating flexible bronchoscopy. In this study, we aimed to evaluate if specific clinical symptoms were predictive of anatomic or functional airway abnormalities detected in bronchoscopy. We analyzed 168 pediatric patients (0-18 years) who underwent flexible bronchoscopy for chronic cough at a tertiary center for this retrospective study. Demographic and clinical data, including cough characteristics and triggering factors, were extracted from medical records. Bronchoscopic findings, including structural and functional airway abnormalities, were documented. Logistic regression and receiver operating characteristic (ROC) analysis were performed to identify predictors of anatomical abnormalities. Bronchoscopy showed that 30% of the cases had unusual structures, with airway malacia (33%), vascular compression (21%), and subglottic stenosis (17%) being the most frequent issues. Younger age (OR = 0.84; 95% CI: 0.75-0.94; p = 0.002) and dry cough phenotype (p = 0.002) were significantly associated with anatomical abnormalities, whereas second-hand smoke exposure and gastroesophageal reflux disease (GERD) were not. ROC analysis demonstrated moderate predictive power (AUC = 0.74) for identifying anatomical abnormalities based on clinical parameters.

Airway malacia, vascular compression and subglottic stenosis are the most common structural and functional airway abnormalities in children with chronic cough. This study has shown that detecting anatomical or functional airway abnormalities with bronchoscopy is more common in young children with prolonged cough.

• Flexible bronchoscopy is a key diagnostic tool for pediatric chronic cough when non-invasive evaluations are inconclusive, routinely identifying anomalies such as airway malacia, vascular compression, and subglottic stenosis. • Current guidelines offer limited guidance on which clinical features should prompt early bronchoscopy referral in children with chronic cough.

• Younger age and a dry cough phenotype are independent predictors of anatomical airway abnormalities on flexible bronchoscopy (OR = 0.84; AUC = 0.74). • A symptom-based decision algorithm incorporating age, cough type, and gender demonstrates moderate discriminative power to guide bronchoscopy referral and may optimize diagnostic yield.