Management of Persistent Cough in Optimized Asthma

1. Saline Nebulization Is Not Recommended

The CHEST guideline (2020) does not recommend isotonic (0.9 %) saline nebulization as a symptom‑relieving adjunct for persistent cough in patients already receiving optimized inhaled corticosteroid/long‑acting β‑agonist (ICS/LABA) therapy, because no guideline or evidence supports this intervention. 1
The British Thoracic Society (BTS) nebulizer guidelines restrict nebulized therapy in chronic asthma to bronchodilators (β‑agonists and ipratropium) only and make no mention of saline for symptom relief. 2

Confirm that the cough is truly asthma‑related by measuring airway inflammation (sputum eosinophils, blood eosinophils, or fractional exhaled nitric oxide). Eosinophilic inflammation predicts a favorable response to corticosteroids. 1
Consider non‑asthmatic eosinophilic bronchitis (NAEB) as an alternative diagnosis; it presents as isolated chronic cough without airflow limitation or airway hyper‑responsiveness but responds to inhaled corticosteroids. 1
Exclude other common causes of chronic cough—gastro‑oesophageal reflux disease, upper‑airway cough syndrome, and chronic rhinosinusitis—before escalating asthma‑specific therapy. 1

Increase the dose of inhaled corticosteroid within the existing ICS/LABA combination when the patient is on a low‑to‑medium dose. 1
Add a leukotriene receptor antagonist (e.g., montelukast 10 mg once daily for adults) as the next step after alternative causes have been ruled out. 1
The CHEST guideline explicitly recommends stepping up the ICS dose and adding a leukotriene inhibitor for incomplete response of asthma‑related cough to optimized therapy. 1

If cough remains the isolated symptom despite optimized ICS/LABA therapy, the presentation may represent cough‑variant asthma, which follows the same stepwise escalation approach as classic asthma. 1
β‑agonist + ICS therapy (as provided by the current ICS/LABA regimen) is appropriate for CVA. 1

Nebulized bronchodilators (salbutamol or terbutaline) should never be used as chronic daily therapy for cough alone. 2
In chronic asthma, nebulized β‑agonists are reserved for patients at Step 4 or higher who have persistent daily wheeze despite optimized controller therapy; they require documented bronchodilation (≥15 % improvement in peak flow) during a 2‑week home trial before long‑term prescription. 2

The lack of any recommendation for saline nebulization across multiple high‑quality guidelines (CHEST 2020, BTS, GINA‑derived recommendations) constitutes strong (high‑level) consensus that this intervention is not evidence‑based for asthma‑related cough. [1][2]