| Long-term exposure to allergens can attenuate inflammation and revert airway hyperreactivity to normal responsiveness. |
| Viral infection can cause dysfunction of M2 muscarinic receptors leading to increased release of acetylcholine and airway hyperreactivity. |
| They reduce mucosal oedema and bronchial hyperreactivity thus relieving acute symptoms and preventing structural damage to the lungs. |
| Asthma is characterized by airway hyperreactivity, inflammation, and atopy. |
