What is the best approach to manage a cough in an adult patient with no significant medical history?

Management of Cough in Adults with No Significant Medical History

The approach to managing cough depends critically on duration: acute cough (<3 weeks) requires minimal intervention and reassurance, while chronic cough (>8 weeks) demands systematic investigation starting with chest radiograph and spirometry, followed by empiric treatment trials targeting the three most common causes—upper airway cough syndrome, asthma, and gastroesophageal reflux disease. 1

Acute Cough Management (<3 weeks)

For acute cough, reassurance and symptomatic treatment are appropriate as this is typically viral and self-limiting. 1

• Most acute coughs are associated with viral upper respiratory tract infections and resolve spontaneously without specific treatment 1
• Over-the-counter preparations may provide subjective benefit, though evidence for specific pharmacological effects is limited 1
• Dextromethorphan can be used for symptomatic relief as a cough suppressant 2
• Guaifenesin helps loosen phlegm and thin bronchial secretions to make coughs more productive 3

Red Flags Requiring Further Investigation in Acute Cough:

• Hemoptysis 1
• Prominent systemic illness 1
• Suspicion of inhaled foreign body 1
• Suspicion of lung cancer 1

Chronic Cough Management (>8 weeks)

Mandatory Initial Workup

All patients with chronic cough require chest radiograph and spirometry—these are non-negotiable baseline investigations. 1, 4

• Obtain detailed history focusing specifically on: smoking status, ACE inhibitor use, occupational exposures, and symptoms of upper airway disease, reflux, or asthma 1, 4
• Physical examination should concentrate on upper airway, chest auscultation, and signs of reflux disease 1
• Assess cough severity and quality of life impact using visual analogue scores 1, 4

Critical First Step: Medication Review

Immediately discontinue ACE inhibitors if the patient is taking them—no patient with troublesome cough should continue these medications. 1, 4

• ACE inhibitor-induced cough is a common and completely reversible cause 4, 5
• Cough may persist for weeks after discontinuation, so allow adequate time for resolution 1

Smoking Cessation

Strongly encourage smoking cessation as it leads to significant remission in cough symptoms. 1

• Smoking is one of the commonest causes of persistent cough and appears dose-related 1

Systematic Empiric Treatment Algorithm

The three most common causes accounting for the vast majority of chronic cough cases are: upper airway cough syndrome (UACS), asthma, and gastroesophageal reflux disease (GERD). 4, 6, 7

Step 1: Treat Upper Airway Cough Syndrome First

Begin with a first-generation antihistamine-decongestant combination as UACS is the most common cause. 4, 5

• Allow at least 1-2 weeks for response 4
• If prominent upper airway symptoms are present, add topical corticosteroid 1

Step 2: Evaluate and Treat for Asthma

If UACS treatment fails, perform bronchial provocation testing (methacholine challenge) as cough-variant asthma commonly presents with normal spirometry. 1, 4, 5

• A negative methacholine challenge essentially excludes asthma 4
• If methacholine testing is unavailable, use a 2-week trial of oral corticosteroids (e.g., prednisone) 1, 4
• Lack of response to a two-week oral steroid trial effectively rules out eosinophilic airway inflammation 1, 4
• If asthma is confirmed, initiate combination therapy with inhaled corticosteroids and inhaled β-agonists 5

Common Pitfall: Do not rely solely on spirometry to diagnose asthma—cough-variant asthma frequently has normal spirometry but positive bronchoprovocation testing 4, 5

Step 3: Treat Gastroesophageal Reflux Disease

Failure to consider GERD is a common reason for treatment failure, and reflux-associated cough may occur without any gastrointestinal symptoms. 1, 4

• Initiate intensive acid suppression with proton pump inhibitors and alginates for a minimum of 3 months 1, 4
• This extended duration is critical—inadequate trial periods lead to missed diagnoses 4
• Empiric treatment is preferred over diagnostic testing as the initial approach 4

Recognition of Multifactorial Cough

Chronic cough is frequently multifactorial, with patients commonly having two or even all three common diagnoses simultaneously—the cough will not resolve until all contributing factors are effectively treated. 4

When Initial Workup is Normal

If chest radiograph and spirometry are normal, this does not exclude disease as both tests are specific but not sensitive. 4

• Proceed with the systematic empiric treatment algorithm described above 4
• Most cases will respond to sequential treatment trials 1, 4

Advanced Investigation

Consider high-resolution computed tomography if other targeted investigations are normal and empiric treatments have failed. 1, 4

• HRCT may reveal bronchiectasis, interstitial lung disease, or occult malignancy 4
• Bronchoscopy should be undertaken if inhalation of foreign body is suspected 1
• Consider bronchoscopy for structural abnormalities or endobronchial lesions 4

Specialist Referral

Chronic cough should only be labeled as idiopathic after thorough assessment at a specialist cough clinic. 1, 4

• Refer when the condition remains undiagnosed after systematic evaluation of UACS, asthma, eosinophilic bronchitis, and GERD 4, 5
• Referral to a specialist cough clinic should be encouraged for refractory cases 1

Treatment Monitoring

Formally quantify treatment effects using validated cough severity measures. 1

• This ensures objective assessment of therapeutic response 1
• Adjust treatment based on documented improvement or lack thereof 1