Asthma and COPD: distinct diseases or components of a continuum?

Asthma and COPD are two chronic bronchial diseases sharing several features including airways obstruction, inflammation, and clinical manifestations. However, they are also characterized by specific features in terms of determinants, natural history, physiological and imaging characteristics. Although their pharmacological treatment relies mostly on the same inhaled drugs, the strategy guiding their use is different, especially with respect to the position of inhaled corticosteroids. While these agents are the cornerstone of asthma management, they are indicated in COPD patients who share features with asthma, that is, eosinophilic inflammation. Whether asthma and COPD should be considered distinct disorders or as components of a continuum, is a matter of debate. Further research is needed before we can firmly choose between these hypotheses. Meanwhile, it remains crucial for both clinical practice and research to follow a rigorous diagnostic approach to properly characterize patients in terms of disease labeling, endotype, phenotype, and treatable traits.