From: Cough variant asthma and atopic coughAsma variante con tosse e tosse atopica
Asthma | Cough variant asthma | Atopic cough | Eosinophilic bronchitis | |
---|---|---|---|---|
Symptoms | Cough, breathlessness, wheeze | Cough only | Cough only | Cough and sputum |
Atopy | Common | Common | Common | As in general population |
Variable airflow obstruction | + | ± | - | - |
Airway hyper-responsiveness | + | + | - | - |
Capsaicin cough hyper-responsiveness | ± | ± | - | + |
Bronchodilator response | + | + | - | - |
Corticosteroid response | + | + | + | + |
Response to H1 antagonist | ± | ± | + | NK |
Progression to asthma | n/a | 30% | rare | 10% |
Sputum eosinophilia (> 3%) | Frequent | Frequent | Frequent | Always (by definition) |
Submucosal eosinophils | ↑ | ↑ | ↑ | ↑ |
BAL eosinophilia | ↑ | ↑ | ↓ | ↑ |
Mast cells in ASM | ↑ | ↓ | NK | ↓ |
Basement membrane thickness | ↑ | ↑ | NK | ↑ |