Chronic cough in children

Cough as a symptom is one of the most common reasons for acute presentations to doctors. The burden of illness (number of presentations to doctors, impaired quality of life, and stress to parents) associated with chronic cough (>4 wk duration) in children is high and is independent of the etiology. When the chronic cough resolves, the level of stress and quality of life scores significantly improve to population norms. Moreover, chronic cough can be a symptom of an underlying serious disease such as aspiration lung disease or bronchiectasis. Thus, all children with cough require a systematic evaluation and approach. This approach, which is different from adults, is briefly outlined in this review. Physiological reasons why chronic cough in children is different from adults includes the domains that relate to (i) cough-specific physiology, (ii) general respiratory physiology, (iii) other direct systems such as the immune system that influence the respiratory system, and (iv) other general physiology. Several conditions associated with chronic cough in children have further been studied recently. These conditions that include protracted bacterial bronchitis, obstructive sleep apnea, tracheomalacia, and exercise-associated cough are also discussed in this review.