What are the management options for a persistent cough?

Management of Persistent Cough

The management of persistent cough requires a systematic diagnostic approach followed by targeted treatment of the underlying cause, as this strategy has been shown to be most effective for improving morbidity, mortality, and quality of life. 1

Diagnostic Approach

Initial Evaluation

• Mandatory baseline investigations:
  • Chest radiograph (to rule out malignancy, infection, or other structural abnormalities)
  • Spirometry with bronchodilator response 1
  • Detailed history focusing on:
    • Duration and character of cough
    • Associated symptoms (wheezing, sputum production, reflux symptoms)
    • Medication review (especially ACE inhibitors)
    • Occupational exposures
    • Smoking status

Common Causes of Persistent Cough

1. Asthma and cough-variant asthma
2. Gastroesophageal reflux disease (GORD)
3. Upper airway cough syndrome (rhinosinusitis)
4. Medication-induced (especially ACE inhibitors)
5. Smoking
6. Eosinophilic bronchitis
7. Post-infectious cough
8. Occupational exposures
9. COPD and bronchiectasis
10. Lung cancer 1, 2, 3

Management Algorithm

Step 1: Address Obvious Causes

• Stop ACE inhibitors - No patient with troublesome cough should continue on ACE inhibitors 1

  • Cough may take up to 40 weeks to resolve after discontinuation
  • Consider angiotensin II receptor blockers as alternatives

• Smoking cessation - Should be strongly encouraged as it significantly improves cough symptoms 1

Step 2: Empiric Treatment Based on Most Likely Cause

For suspected asthma/eosinophilic bronchitis:

• Trial of oral corticosteroids (prednisolone) for 2 weeks
• If no response after 2 weeks, eosinophilic airway inflammation is unlikely 1
• Consider inhaled corticosteroids for maintenance if responsive

For suspected GORD:

• Intensive acid suppression with proton pump inhibitors and alginates for minimum 3 months 1
• Consider lifestyle modifications (weight loss, avoiding late meals)
• Antireflux surgery may be effective in carefully selected cases

For suspected upper airway cough syndrome:

• Trial of topical nasal corticosteroids when upper airway symptoms are prominent 1
• Consider first-generation antihistamines with decongestants

Step 3: Additional Investigations if Initial Management Fails

• Bronchial provocation testing for patients with normal spirometry 1
• Bronchoscopy if foreign body aspiration is suspected 1
• High-resolution CT scan when other targeted investigations are normal 1

Step 4: Management of Refractory Cough

For cough persisting despite appropriate treatment of identified causes:

• Consider referral to specialist cough clinic 1
• Trial of neuromodulatory agents (gabapentin, pregabalin) 2, 4
• Speech therapy techniques 2, 4

Symptomatic Management

For productive cough:

• Guaifenesin can help loosen phlegm and thin bronchial secretions to make coughs more productive 5
• Warning: Should not be used if cough lasts more than 7 days, is accompanied by fever, rash, or persistent headache without medical consultation 5

For dry, irritating cough:

• Dextromethorphan may provide symptomatic relief 6
• Warning: Contraindicated with MAOIs and should not be used if cough lasts more than 7 days or occurs with fever, rash, or persistent headache 6
• Peripherally acting antitussives like levodropropizine may be beneficial, especially in children 7

Important Caveats and Pitfalls

• Multiple causes are common - persistent cough often has more than one contributing factor 1, 3
• GORD-related cough may occur without typical reflux symptoms 1
• Cough hypersensitivity syndrome should be considered when evaluation for common causes is negative 2, 4
• Red flag symptoms requiring urgent investigation include:
  • Hemoptysis
  • Weight loss
  • Recurrent pneumonia
  • Persistent fever 2
• Cough suppression may be contraindicated when cough clearance is important (e.g., bronchiectasis with productive cough) 1
• Chronic cough should only be labeled as idiopathic after thorough assessment at a specialist cough clinic 1

Remember that persistent cough significantly impacts quality of life and warrants thorough investigation and targeted treatment to address the underlying cause rather than just symptomatic management.