[Comment] Inclusion of small airway dysfunction in asthma assessment and management: a place for impulse oscillometry?

In 1969, Ann Woolcock had already identified “The silent zone of the lung”1—ie, the small airways—as a vulnerable area for lung disease while remaining clinically silent. However, small airways are still neglected, despite being the major, and sometimes only, site of airway obstruction in asthma and chronic obstructive pulmonary disease.2 Small airway dysfunction can contribute to inadequate control, and asthma exacerbations remain a substantial problem, despite important advances in therapeutic possibilities.