What is the appropriate workup and treatment for a 23-year-old male with a chronic dry cough and no upper respiratory infection (URI) symptoms?

Evaluation and Management of Chronic Dry Cough in a Young Adult

The appropriate workup for a 23-year-old male with chronic dry cough lasting several months without URI symptoms should begin with a chest radiograph, followed by targeted investigations for common causes including upper airway cough syndrome, asthma, GERD, and non-asthmatic eosinophilic bronchitis, according to established guidelines. 1

Initial Evaluation

1. Chest Radiography:

   • Essential first-line investigation to rule out structural abnormalities 1
   • Normal chest radiograph narrows differential but doesn't eliminate need for further workup

2. Pulmonary Function Testing:

   • Spirometry with bronchodilator response
   • Consider bronchial challenge testing if spirometry is normal but asthma is suspected 1
   • Fractional exhaled nitric oxide (FeNO) to assess for eosinophilic inflammation

3. Targeted History Elements:

   • Medication review (especially ACE inhibitors)
   • Tobacco/marijuana use and environmental exposures
   • Timing of cough (nocturnal, postprandial, exercise-induced)
   • Associated symptoms (heartburn, postnasal drip, wheezing)

Systematic Evaluation for Common Causes

1. Upper Airway Cough Syndrome (UACS)

• Evaluate for postnasal drip, nasal congestion, throat clearing
• Consider empiric trial of antihistamine-decongestant combination for 2 weeks 2
• If symptoms improve, continue treatment; if not, move to next cause

2. Asthma

• Even without classic symptoms, consider cough-variant asthma
• If spirometry/bronchoprovocation testing suggests asthma:
  • Trial of inhaled corticosteroids (not oral prednisone) 2, 3
  • Consider adding montelukast if partial response 3

3. Non-asthmatic Eosinophilic Bronchitis (NAEB)

• Consider if normal spirometry but elevated FeNO
• Trial of inhaled corticosteroids for 2-4 weeks 1

4. Gastroesophageal Reflux Disease (GERD)

• Even without typical reflux symptoms, GERD can cause chronic cough
• Trial of proton pump inhibitor with lifestyle modifications for 4-8 weeks 1
• Consider adding prokinetic agent if partial response

Management Algorithm

1. First-line approach: Treat most likely cause based on history and initial testing
2. Sequential therapy: If no response after 2-4 weeks, add treatment for next most likely cause
3. Reassessment: If cough persists after treating common causes for appropriate duration:
   • Consider high-resolution CT chest to evaluate for bronchiectasis or interstitial lung disease 1
   • Consider bronchoscopy if CT abnormal or cough remains unexplained 1

Additional Considerations for Persistent Cough

If cough persists despite addressing common causes:

1. Advanced Imaging:

   • High-resolution CT chest is recommended after failed empiric treatment trials 1
   • Non-contrast CT is usually sufficient unless vascular etiology suspected 1

2. Consider Refractory or Unexplained Chronic Cough:

   • If cough persists >8 weeks despite appropriate evaluation and treatment 1
   • Consider neuromodulator therapies (gabapentin, amitriptyline) 1, 2
   • Speech therapy-based interventions may be beneficial 1

Common Pitfalls to Avoid

• Premature diagnosis closure: Multiple causes may coexist and require sequential or combination therapy
• Inadequate treatment duration: Some causes (particularly GERD) may require longer treatment trials
• Overlooking medication causes: Particularly ACE inhibitors
• Insufficient diagnostic testing: Relying solely on empiric treatment without objective testing
• Missing red flags: Weight loss, hemoptysis, recurrent pneumonia require more urgent evaluation

Key Points for This Patient

For a 23-year-old with chronic dry cough without URI symptoms:

• Young age makes serious pathology less likely but doesn't eliminate need for systematic evaluation
• Asthma and upper airway cough syndrome are particularly common in this age group
• Occupational and environmental exposures should be carefully assessed
• Psychogenic or habit cough should be considered if all evaluations are negative

Following this systematic approach will lead to diagnosis and effective treatment in the vast majority of cases of chronic cough.