LAUSR

Abstract Background Chronic cough (CC) is a common respiratory symptom in children, often linked to allergic conditions, environmental exposures, and potentially indicative of underlying asthma. Objective To investigate the relationships of CC in children with allergic predispositions, environmental exposures, and airway inflammatory markers. Methods A case-control study was conducted at a tertiary hospital. Data on cough duration, personal and family allergic histories, and environmental exposures were collected. Airway inflammation was assessed using fractional exhaled nitric oxide (FeNO50), and lung function was evaluated via spirometry. Results Children with CC showed a higher prevalence of allergic conditions, including rhinitis (74.77% vs. 24.13%, OR = 9.312, p < 0.0001), food allergy (59.81% vs. 27.59%, OR = 3.907, p = 0.0017), eczema (55.14% vs. 31.03%, OR = 2.731, p = 0.0213), and family history of allergies (71.96% vs. 27.59%, OR = 6.738, p < 0.001). Environmental exposures, such as household smoking (55.14% vs. 20.69%, OR = 4.712, p = 0.001) and mold exposure (28.68% vs. 7.35%, OR = 3.442, p = 0.0251), were more common in the CC group. CC children exhibited elevated FeNO50 (median: 18 vs. 14 ppb, p = 0.0153) and impaired small airway function (FEF75%pred: 53.84 ± 20.21 vs. 65.07 ± 28.52, p = 0.0170). Conclusions Pediatric CC is strongly associated with allergic predispositions, environmental exposures, and eosinophilic airway inflammation, potentially reflecting an asthma-related phenotype.