What is the appropriate management for a patient presenting with a chronic cough?

Management of Chronic Cough in Adults

Begin with chest radiography and spirometry as your initial diagnostic tests, then systematically treat the three most common causes—upper airway cough syndrome (UACS), asthma, and gastroesophageal reflux disease (GERD)—using sequential and additive empiric therapy. 1, 2, 3

Initial Assessment and Red Flags

Critical First Steps

• Immediately discontinue ACE inhibitors if the patient is taking them, as this alone resolves cough in most cases within days to 2 weeks (median 26 days). 3, 4
• Strongly counsel smoking cessation, as 90% of patients with chronic bronchitis will have complete resolution of cough after quitting, typically within 4 weeks. 1, 3, 4
• Screen for red flags requiring urgent evaluation: hemoptysis, smoker >45 years with new or changed cough pattern, prominent dyspnea, hoarseness, systemic symptoms (fever, weight loss), trouble swallowing, vomiting, or recurrent pneumonia. 2, 5

Baseline Investigations

• Obtain chest radiography in all patients with chronic cough to rule out serious pathology like malignancy, pneumonia, or pulmonary embolism. 1, 2, 3
• Perform spirometry with bronchodilator response testing to identify obstructive airways disease and assess for reversibility. 1
• Do NOT use peak expiratory flow measurements as they are less accurate than FEV1 for diagnosing airflow obstruction. 1

Sequential Empiric Treatment Algorithm

Step 1: Treat Upper Airway Cough Syndrome (UACS) First

• Start a first-generation antihistamine/decongestant combination (e.g., brompheniramine with sustained-release pseudoephedrine) as first-line therapy. 1, 3, 4
• Do NOT use newer non-sedating antihistamines, as they are ineffective for UACS-related cough. 4
• If prominent upper airway symptoms are present, add topical nasal corticosteroids. 1
• Expect initial response within 1-2 weeks, though complete resolution may take several weeks. 3, 4

Step 2: Add Asthma Treatment if Incomplete Response After 2-4 Weeks

• Initiate inhaled corticosteroids combined with long-acting β-agonists (e.g., fluticasone/salmeterol twice daily). 3, 4
• Remember that normal spirometry does NOT exclude asthma or eosinophilic bronchitis as causes of chronic cough. 1
• If spirometry is normal and asthma is suspected, consider a 2-week trial of oral prednisolone to assess for corticosteroid-responsive cough. 1
• Monitor for response within 2-4 weeks. 3, 4

Step 3: Add GERD Treatment if Still Inadequate Response

• Start intensive acid suppression with proton pump inhibitors plus alginates for empiric GERD treatment. 1, 3, 4
• Continue previous treatments for UACS and asthma, as chronic cough is frequently multifactorial with multiple simultaneous causes. 1, 3, 4
• Treat for a minimum of 3 months, as GERD-related cough responds slowly. 1, 4
• Note that reflux-associated cough often occurs WITHOUT gastrointestinal symptoms. 1

Advanced Evaluation When Initial Treatment Fails

When to Pursue Additional Testing

• Reserve high-resolution CT (HRCT) for patients with abnormal chest radiographs or those who fail initial empiric treatment, as routine CT in all chronic cough patients has low clinical yield. 2
• Consider bronchoscopy to evaluate for occult airway disease (endobronchial tumor, sarcoidosis, foreign body aspiration, eosinophilic or lymphocytic bronchitis) when standard treatments fail. 1
• Perform bronchial provocation testing if spirometry is normal to confirm or exclude asthma, though a negative test does not rule out steroid-responsive cough. 1, 3

Refractory Chronic Cough

• Consider cough hypersensitivity syndrome and treat with gabapentin or pregabalin when extensive evaluation is negative and cough persists despite optimal treatment. 5, 6
• Low-dose morphine is the preferred agent for refractory cough when other treatments fail. 6
• Refer to a specialist cough clinic before labeling cough as idiopathic or unexplained. 1

Critical Pitfalls to Avoid

• Never attribute chronic cough to a single cause without treating all common etiologies, as more than one condition frequently coexists. 1, 4, 7
• Do not stop partially effective treatments when adding new therapies—maintain all treatments that provide some benefit. 1, 4
• Avoid using diagnostic algorithms in patients with abnormal chest radiographs—investigate the radiographic abnormality directly. 1
• Do not overlook extrapulmonary causes, particularly GERD, which is frequently missed in general respiratory clinics. 1
• Ensure adequate treatment duration and dosing before concluding a therapy has failed—many treatments require weeks to months for full effect. 1