Treatment of Continuous Cough in Adults
A systematic approach targeting the three most common causes—upper airway cough syndrome, asthma/eosinophilic bronchitis, and gastroesophageal reflux disease—should be initiated sequentially after obtaining baseline chest radiograph and spirometry, with each empiric treatment trial lasting 2-4 weeks before moving to the next. 1, 2
Immediate Actions Before Starting Treatment
Stop ACE inhibitors immediately if the patient is taking one, as this is a common reversible cause with cough resolution typically occurring within days to 2 weeks (median 26 days). 3, 2
Encourage smoking cessation as the priority for current smokers, as smoking is one of the commonest causes of persistent cough and symptoms typically resolve within 4 weeks of quitting. 3, 2
Essential Baseline Investigations
- Obtain chest radiograph to exclude pneumonia, malignancy, heart failure, or other serious pathology before proceeding with empiric treatment. 1, 2
- Perform spirometry to assess for airflow obstruction and guide treatment decisions. 1, 2
Sequential Empiric Treatment Algorithm
First-Line: Upper Airway Cough Syndrome (UACS)
Start with a first-generation antihistamine-decongestant combination as the initial empiric treatment for upper airway cough syndrome. 1, 2
- Add topical nasal corticosteroids if prominent upper airway symptoms exist (nasal congestion, postnasal drip, throat clearing). 3, 2
- Continue treatment for 2-4 weeks and assess response. 1
Second-Line: Asthma/Eosinophilic Bronchitis
If UACS treatment fails, initiate inhaled corticosteroids plus bronchodilators for suspected asthma or eosinophilic bronchitis. 1, 2
- Consider bronchial provocation testing (methacholine challenge) if available to confirm asthma, though a negative test does not rule out steroid-responsive cough. 3, 1
- A two-week oral steroid trial effectively rules out eosinophilic airway inflammation if there is no response. 3
- Continue treatment for 2-4 weeks if response is positive. 1
Third-Line: Gastroesophageal Reflux Disease (GERD)
Initiate intensive acid suppression with high-dose proton pump inhibitors plus alginates for a minimum of 3 months, as GERD-related cough may occur without gastrointestinal symptoms and response is more variable than with UACS or asthma. 3, 2
- Failure to consider GORD as a cause is a common reason for treatment failure. 3
- Response may take 2 weeks to several months. 2
Important Clinical Considerations
These three conditions (UACS, asthma, GERD) account for 85-100% of chronic cough cases, so systematic evaluation of each is essential. 2, 4
Treatments should be additive rather than substitutive—if partial response occurs with one treatment, continue it while adding the next empiric trial. 2
Formally quantify treatment effects using validated cough severity measures rather than relying solely on subjective assessment. 3, 1
When to Consider Specialist Referral
Refer to a specialist cough clinic when the condition remains undiagnosed after systematic evaluation of UACS, asthma, and GERD, or if symptoms persist despite adequate treatment trials. 3, 1
Consider high-resolution computed tomography if other targeted investigations are normal and empiric treatments have failed. 3, 1
Refractory Cough Management
For patients with persistent cough despite the above approach:
- Consider neuromodulators such as low-dose gabapentin or pregabalin for refractory chronic cough. 2, 5, 6
- Speech pathology therapy with cough suppression techniques may be beneficial. 2
Critical Pitfalls to Avoid
Do not suppress cough when cough clearance is important (e.g., in bronchiectasis or active infection), as suppression may be contraindicated. 3
Do not proceed with extensive diagnostic testing before completing empiric treatment trials for the three most common causes, as this is more cost-effective. 3, 1
Do not continue ACE inhibitors in any patient with troublesome cough, as this is a readily reversible cause. 3