Abstract Small airway disease (SAD) is increasingly recognized as an important but underdiagnosed component of asthma, particularly in the pediatric population. It contributes to typical asthma symptoms, poor disease control, and exacerbations through mechanisms such as airway inflammation, remodeling, and ventilation heterogeneity. Conventional spirometry primarily reflects proximal airway function and provides only indirect markers of distal airway involvement, limiting its sensitivity in detecting SAD, especially in children. Advanced techniques such as inert gas washout and hyperpolarized magnetic resonance imaging offer detailed assessment but are largely confined to research settings. Oscillometry has emerged as a practical, effort-independent tool that assesses respiratory mechanics during tidal breathing and may identify small airway dysfunction even when spirometry is normal. It is particularly useful in children who are unable to perform reliable spirometry. However, its widespread clinical application is limited by variability across devices, lack of standardized cutoff values, and insufficient pediatric reference data. Recognition of SAD has important therapeutic implications, including optimization of inhaled drug delivery using extrafine formulations and targeted use of biologic therapies in severe asthma. Oscillometry should be used as an adjunct and interpreted alongside clinical assessment and conventional investigations.
Manjunath Ventaka Krishnamurthy (Thu,) studied this question.