What is the recommended workup for a patient presenting with chronic cough?

Recommended Workup for Chronic Cough

A systematic diagnostic approach with selected testing and empirical treatment trials is the most effective way to manage chronic cough, defined as cough lasting more than 8 weeks. 1

Initial Evaluation

Required Initial Tests

• Detailed history and physical examination focusing on:
  • Duration of cough
  • Smoking history
  • Medication review (particularly ACE inhibitors)
  • Occupational exposures
  • Upper airway symptoms
  • Reflux symptoms (may be absent in reflux-related cough)
  • Asthma symptoms
• Chest radiograph (mandatory) 1
• Spirometry (mandatory) 1

Red Flag Symptoms Requiring Urgent Evaluation

• Hemoptysis
• Significant weight loss
• Fever
• Recurrent pneumonia
• Prominent systemic illness 1, 2

Systematic Investigation of Common Causes

1. Medication-Induced Cough

• Discontinue ACE inhibitors in all patients with troublesome cough 1
• Allow 4 weeks for resolution after discontinuation

2. Smoking-Related Cough

• Encourage smoking cessation as it significantly reduces cough symptoms 1

3. Asthma/Eosinophilic Airway Inflammation

• Bronchial provocation testing for patients with normal spirometry 1
• Induced sputum to assess for eosinophilic bronchitis 1
• Trial of inhaled corticosteroids for 2-4 weeks
• Consider oral corticosteroid trial (2 weeks) if no response to inhaled therapy 1

4. Upper Airway Cough Syndrome (UACS)

• ENT examination before sinus imaging 1
• Trial of topical nasal corticosteroids for prominent upper airway symptoms 1
• Consider first-generation antihistamine-decongestant combination for 2-4 weeks

5. Gastroesophageal Reflux Disease (GERD)

• Empiric trial of intensive acid suppression with proton pump inhibitors and alginates for minimum 3 months 1, 3
• Consider 24-hour pH monitoring if empiric therapy fails 1, 3
• High-resolution manometry to evaluate esophageal function 3

Advanced Testing (if initial evaluation negative)

• High-resolution CT scan of the chest 1, 2
• Bronchoscopy if foreign body inhalation is suspected 1
• Fibreoptic laryngoscopy for suspected laryngeal disorders 1
• 24-hour esophageal pH monitoring or impedance-pH testing 1, 3

Management of Refractory Chronic Cough

If cough persists despite thorough evaluation and treatment trials:

1. Refer to specialist cough clinic 1
2. Consider neuromodulator therapy:
   • Gabapentin 1, 2
   • Amitriptyline 1
   • Pregabalin 2
3. Speech and language therapy interventions 1, 2

Common Pitfalls to Avoid

1. Inadequate treatment duration - GERD treatment requires minimum 3 months 1, 3
2. Failure to consider multiple causes - Cough often has more than one contributing factor 1
3. Missing GERD as a cause - Reflux cough may occur without typical GERD symptoms 1
4. Premature diagnosis of idiopathic cough - Should only be made after thorough specialist assessment 1
5. Overlooking non-asthmatic eosinophilic bronchitis - Requires induced sputum analysis 1
6. Discontinuing evaluation after negative initial tests - Further specialized testing often needed 1

Diagnostic Algorithm Summary

1. Rule out red flags requiring urgent evaluation
2. Discontinue ACE inhibitors and encourage smoking cessation
3. Perform mandatory tests (chest X-ray, spirometry)
4. Conduct empirical treatment trials for common causes:
   • Asthma/eosinophilic bronchitis (inhaled/oral corticosteroids)
   • UACS (nasal corticosteroids, antihistamine-decongestant)
   • GERD (intensive PPI therapy for 3 months)
5. Proceed to specialized testing if empirical treatments fail
6. Consider neuromodulators and speech therapy for refractory cough
7. Refer to specialist cough clinic for persistent unexplained cough

This approach will identify the cause of chronic cough in 82-100% of cases when systematically applied 1.