From Type 2 Inflammation to Mucociliary Dysfunction: Individualized Pulmonary Rehabilitation in Children with Asthma and Bronchiectasis

Asthma and bronchiectasis may coexist in children, particularly in those with severe or difficult-to-treat respiratory disease, creating a complex clinical setting in which airway inflammation, bronchial hyperresponsiveness, mucus retention, impaired mucociliary clearance, recurrent infection, and functional impairment interact. This review critically examines the interacting pathophysiological mechanisms involving Type 2 airway inflammation, mucus hypersecretion and plugging, mucociliary dysfunction, infection, and structural airway injury in children with coexisting asthma and bronchiectasis. Particular attention is given to the functional consequences of this interaction, including exercise intolerance, physical deconditioning, respiratory muscle dysfunction, and reduced participation in daily life and age-appropriate physical activity. Available evidence on airway-clearance techniques, structured exercise training, respiratory muscle training, and the management of exercise-induced bronchoconstriction is critically evaluated, with pediatric evidence clearly distinguished from adult-derived extrapolations. We propose a mechanism-informed rehabilitation framework in which interventions are tailored to the predominant clinical and functional features of each child, including mucus retention, bronchial hyperresponsiveness, reduced exercise capacity, respiratory muscle impairment, and functional decline associated with recurrent exacerbations. This multidisciplinary approach integrates airway-clearance techniques, individualized exercise training, optimized asthma management, infection control, and longitudinal functional reassessment. Evidence specifically addressing children with coexisting asthma and bronchiectasis remains limited, and prospective pediatric studies are required to validate individualized rehabilitation strategies and determine their impact on long-term respiratory and patient-centered outcomes.