Evaluation and Management of Chronic Cough

Initial Mandatory Investigations

Obtain a chest X-ray in all patients with chronic cough (>8 weeks duration) to rule out serious pathology including malignancy, tuberculosis, bronchiectasis, and interstitial lung disease 1, 2
Approximately 31% of chest radiographs in patients with persistent cough will be abnormal or yield a diagnosis 1
Perform spirometry in all patients with chronic cough to identify airflow obstruction and assess bronchodilator response 1, 2
Measure FEV1 before and after inhaling a short-acting β2-agonist if obstruction is present 1
Normal spirometry does not exclude asthma or eosinophilic bronchitis as causes of chronic cough 2

In areas with high TB prevalence, obtain sputum smears and cultures for acid-fast bacilli along with chest radiography 3, 4
TB should be considered but not to the exclusion of more common etiologies like upper airway cough syndrome, asthma, and gastroesophageal reflux disease 3
If the patient has paroxysmal coughing, post-tussive vomiting, or inspiratory whooping, obtain nasopharyngeal culture for Bordetella pertussis 5
Pertussis can cause persistent cough; approximately 10% of chronic cough cases in some series had positive Bordetella testing 1

In patients with normal spirometry and bronchodilator response where cough-predominant asthma or eosinophilic bronchitis is suspected, offer a therapeutic trial of prednisolone (30-40 mg daily for 2 weeks) 1, 2
Alternatively, trial inhaled corticosteroids if the diagnosis is being considered 7
Initiate intensive acid suppression with proton pump inhibitors for a minimum of 2 months if GERD is suspected 8

Finger clubbing with evidence of pleural effusion or lobar collapse (suggests lung cancer) 1
Smoking history with abnormal examination findings 1

Avoid single peak flow measurements for diagnosis—they are less accurate than FEV1 for identifying airflow obstruction 2