What is the management approach for a patient with chronic cough?

Management of Chronic Cough

For patients with chronic cough, systematically treat the most common causes in sequential and additive steps: upper airway cough syndrome (UACS), asthma, gastroesophageal reflux disease (GERD), and nonasthmatic eosinophilic bronchitis (NAEB), as multiple causes frequently coexist. 1

Initial Assessment and Risk Factor Modification

Essential First Steps

• Discontinue ACE inhibitors immediately if the patient is taking them, as they are a common reversible cause of chronic cough 1, 2
• Counsel and assist with smoking cessation for all smokers, as cough may resolve within 4 weeks of quitting 1
• Obtain a chest radiograph to rule out serious pathology such as malignancy, pneumonia, or structural lung disease 1, 3
• Perform spirometry to identify obstructive airway disease and assess for reversibility with bronchodilators 1

Key History Elements to Elicit

• Duration of cough (chronic = >8 weeks in adults) 4, 5
• Current medications, particularly ACE inhibitors 1
• Smoking history and occupational exposures 1
• Red flag symptoms: hemoptysis, fever, weight loss, recurrent pneumonia, or dysphagia requiring immediate advanced evaluation 5

Sequential Treatment Algorithm

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

• Begin with a first-generation antihistamine/decongestant combination as initial empiric therapy 1, 3
• This addresses postnasal drip from rhinitis, sinusitis, or rhinosinusitis 2
• Expect response within 1-2 weeks, though complete resolution may take several weeks 6

Step 2: Address Asthma if UACS Treatment Fails or Is Incomplete

• Initiate inhaled corticosteroids (ICS) combined with long-acting β-agonists (LABA) for suspected asthma 3, 6
• Note that cough-variant asthma may present without wheezing or dyspnea, and spirometry may be normal 1
• If spirometry doesn't show reversible obstruction, perform bronchoprovocation challenge (BPC) to confirm asthma diagnosis 1
• If BPC is unavailable, proceed with an empiric trial of anti-asthma therapy for 2-4 weeks 1, 6

Step 3: Evaluate and Treat Nonasthmatic Eosinophilic Bronchitis (NAEB)

• Consider NAEB if cough persists after treating UACS and asthma 1
• Perform induced sputum testing for eosinophils if available 1
• If testing unavailable, give an empiric trial of inhaled corticosteroids 1, 3
• NAEB patients have normal spirometry and no bronchial hyperresponsiveness, distinguishing them from asthmatics 1

Step 4: Treat Gastroesophageal Reflux Disease (GERD)

• Initiate proton pump inhibitor (PPI) therapy if cough persists despite addressing upper and lower airway causes 1, 3
• GERD-related cough may occur without typical reflux symptoms like heartburn 2
• Add prokinetic therapy if there is inadequate response to PPI alone 3
• Continue previous treatments as cough is often multifactorial 6

Critical Management Principles

Sequential and Additive Therapy

• Do not stop previous treatments when adding new ones, as more than one cause is present in up to 25% of patients 1, 7
• Each treatment trial should last 4-6 weeks before concluding it is ineffective 4
• Approximately 90% of chronic cough cases are due to the four common causes listed above 5

When Standard Approach Fails

Additional Investigations to Consider

• High-resolution CT scan if chest radiograph is normal but suspicion remains for structural disease 4
• Bronchoscopy to evaluate for occult endobronchial disease (tumor, sarcoidosis, foreign body) if targeted treatments fail 1
• Consider bronchoscopy early if foreign body aspiration is suspected 1

Refractory Chronic Cough Management

• If cough persists after systematic evaluation and treatment of common causes, consider cough hypersensitivity syndrome 5
• Low-dose morphine is preferred for symptomatic management of refractory cough 3, 4
• Alternative options include gabapentin or pregabalin for neuromodulation 4, 5
• Refer to a cough specialist before labeling as unexplained/idiopathic cough 1

Common Pitfalls to Avoid

• Do not rely on cough characteristics (timing, quality, productivity) for diagnosis, as they have minimal diagnostic value 1, 3
• Avoid treating only one cause without considering multiple simultaneous etiologies 1, 3
• Do not perform extensive testing upfront; use targeted investigations only after empiric treatment failures 4
• Do not use single PEF measurements to assess for asthma, as they are less accurate than spirometry with FEV1 1
• Ensure adequate treatment duration and dosing before concluding a therapeutic trial has failed 1