What is the approach to managing a patient with chronic cough?

Approach to Chronic Cough

In patients with chronic cough (lasting >8 weeks), systematically treat the most common causes—upper airway cough syndrome (UACS), asthma, gastroesophageal reflux disease (GERD), and non-asthmatic eosinophilic bronchitis (NAEB)—using sequential and additive empiric therapy, as multiple causes frequently coexist. 1

Initial Assessment and Risk Factor Modification

History and Physical Examination

• Determine if the patient is taking an ACE inhibitor, which causes chronic cough and should be discontinued and replaced with an alternative antihypertensive 1, 2
• Assess smoking status, as cessation can resolve cough within 4 weeks 1, 3
• Evaluate for red flag symptoms including hemoptysis, fever, weight loss, recurrent pneumonia, or signs of serious systemic disease that warrant immediate investigation 1, 4
• Note that cough timing and characteristics have limited diagnostic value and should not guide the diagnostic approach 3

Initial Testing

• Obtain chest radiograph to exclude pneumonia, malignancy, interstitial lung disease, or other serious thoracic pathology 2, 5
• Perform spirometry to assess for reversible airflow obstruction suggestive of asthma 6, 4
• Consider exhaled nitric oxide and blood eosinophil count to identify eosinophilic airway inflammation 6

Sequential Treatment Algorithm

Step 1: Treat Upper Airway Cough Syndrome (UACS)

• Initiate therapy with a first-generation antihistamine/decongestant combination (e.g., chlorpheniramine with pseudoephedrine) 1, 2
• Newer non-sedating antihistamines are ineffective for cough and should not be used 3
• Expect improvement within 1-2 weeks, though complete resolution may take several weeks 2
• Continue treatment even if only partial response occurs, as multiple causes often coexist 1

Step 2: Evaluate and Treat Asthma

• If cough persists after UACS treatment, proceed to asthma evaluation 1
• Medical history alone is unreliable for diagnosing asthma as a cause of cough 1
• Perform bronchoprovocation challenge (BPC) if spirometry does not show reversible airflow obstruction 1, 2
• If BPC is unavailable, initiate empiric antiasthma therapy 1
• Start treatment with inhaled corticosteroids (ICS) combined with long-acting β-agonists (LABA), such as fluticasone/salmeterol twice daily 2, 3
• Monitor for response within 2-4 weeks 2
• For refractory cases, add leukotriene receptor antagonists before escalating to oral corticosteroids 3
• A limited trial of oral corticosteroids may be necessary before eliminating asthma from consideration 1

Step 3: Address Non-Asthmatic Eosinophilic Bronchitis (NAEB)

• If UACS and asthma have been treated without cough elimination, consider NAEB 1
• Perform induced sputum testing for eosinophils if available 1, 2
• If induced sputum testing cannot be performed, initiate an empiric trial of inhaled corticosteroids 1, 2
• First-line treatment is inhaled corticosteroids 3

Step 4: Treat Gastroesophageal Reflux Disease (GERD)

• If cough responds only partially or not at all to interventions for UACS, asthma, and NAEB, initiate empiric treatment for GERD with proton pump inhibitors 1, 2
• Continue previous treatments as cough is often multifactorial 2
• Treatment duration should be adequate (typically 8-12 weeks) as GERD-related cough may take longer to resolve 1

Management of Refractory Chronic Cough

When Standard Treatments Fail

• If cough persists despite sequential trials addressing all common causes, consider referral to a cough specialist 1
• Before diagnosing unexplained (idiopathic) cough, perform bronchoscopy to evaluate for occult airway disease including endobronchial tumor, sarcoidosis, suppurative infection, or eosinophilic/lymphocytic bronchitis 1
• Consider uncommon causes such as non-acid reflux, swallowing disorders, congestive heart failure, or habit cough based on clinical findings 1

Symptomatic Management Options

• For refractory chronic cough with uncertain etiology after negative evaluation for life-threatening causes, consider cough hypersensitivity syndrome 4
• Low-dose morphine is the preferred agent for symptomatic management of refractory cough 6
• Gabapentin or pregabalin can be used as alternatives 6, 4
• Speech therapy (cough control therapy) may provide benefit 6, 4

Critical Pitfalls to Avoid

• Do not treat only one potential cause—use sequential AND additive therapy, as more than one cause is present in up to 25% of patients 1, 7
• Do not rely on cough characteristics (timing, quality, productivity) for diagnosis, as they have minimal diagnostic value 1, 3
• Ensure adequate treatment duration and appropriate medication selection before concluding a cause has been ruled out 1
• Do not proceed to extensive diagnostic testing before completing empiric trials for the four most common causes 6
• Avoid using newer non-sedating antihistamines for UACS, as they are ineffective 3