| Asthma | COPD | Overlap Syndrome | |
|---|---|---|---|
| Pathology | Chronic airway inflammation, typically eosinophilic and driven by CD4 cells. Neutrophilic inflammation has been observed in the airways of some asthmatics and is associated with increased steroid resistance. | Chronic airway inflammation, typically neutrophilic and driven by CD8 cells. Eosinophilic inflammation has been observed in the airways of some patients with COPD and is associated with greater steroid sensitivity. | Pathologic overlap in the inflammatory profiles of both asthma and COPD, particularly among the elderly. |
| Pathophysiology | Reversible airway obstruction; progressive deterioration over time is uncommon. | Partially reversible airway obstruction; progressive deterioration overtime is typical. | Functional overlap between asthma and COPD, particularly among the elderly. |
| Treatment of acute exacerbations | |||
| Systemic corticosteroids & inhaled bronchodilators | Improve symptoms and lung function and decrease the length of hospital stay. | Improve symptoms and lung function and decrease the length of hospital stay. | No data available. |
| Maintenance treatment of stable disease | |||
| ICSs | The mainstay of treatment in patients with persistent asthma. | Less effective response. ICSs are recommended for patients with more severe COPD (FEV1 <50% of predicted) whose symptoms are not optimally controlled with inhaled bronchodilators. | No data available. |
| ICS monotherapy is not recommended. | |||
| Inhaled bronchodilators | Inhaled short-acting β2-agonists are the mainstay of treatment for intermittent asthma. | The mainstay of treatment in patients with COPD; inhaled anticholinergics may be more effective than inhaled β2-agonists as monotherapy in COPD. | No data available. |
| Inhaled long-acting β2-agonists monotherapy is not recommended. | |||
FEV1, forced expiratory volume in 1 second; ICS, inhaled corticosteroid.