What is the initial management for a patient presenting with a persistent cough?

Initial Management of Persistent Cough

Begin by immediately discontinuing any ACE inhibitor if the patient is taking one, as this is a common and fully reversible cause of chronic cough. 1, 2

First Steps: History and Risk Stratification

• Classify the cough duration: acute (<3 weeks), subacute (3-8 weeks), or chronic (>8 weeks), as this determines your entire diagnostic and treatment pathway 2, 3
• Identify smoking status immediately and counsel on cessation—90-94% of smokers experience cough resolution within the first year of quitting 2
• Rule out life-threatening conditions first: assess for pneumonia (tachypnea, tachycardia, dyspnea, abnormal lung findings), pulmonary embolism, or cardiac failure, particularly in patients >65 years 1, 3, 4
• Check for respiratory distress indicators: markedly elevated respiratory rate, intercostal retractions, cyanosis, or altered mental status requiring urgent intervention 2, 3

Essential Initial Testing

• Obtain chest radiography if you suspect pneumonia based on clinical findings or if the patient is elderly with atypical presentation 2, 3, 4
• Perform spirometry as part of the basic chronic cough evaluation, though recognize its diagnostic utility is limited 2

Sequential Treatment Approach for Chronic Cough

The three most common causes—upper airway cough syndrome (UACS), asthma, and gastroesophageal reflux disease (GERD)—account for the vast majority of cases and frequently coexist, requiring sequential and additive therapy rather than stopping after identifying one cause. 1, 2, 4

Step 1: Treat Upper Airway Cough Syndrome First

• Start with an oral first-generation antihistamine/decongestant combination (not newer non-sedating antihistamines, which are ineffective for cough) 1, 2, 3
• Add a topical nasal corticosteroid if prominent upper airway symptoms are present 2
• UACS represents 61-67% of chronic cough cases in referral settings 4

Step 2: Evaluate and Treat for Asthma

• If spirometry shows reversible airflow obstruction, treat with inhaled bronchodilators and inhaled corticosteroids 2, 3
• If spirometry is normal but asthma is still suspected, perform bronchoprovocation challenge testing or initiate an empiric trial of inhaled corticosteroids and bronchodilators 1, 2
• For refractory cases, add a leukotriene receptor antagonist before escalating to systemic corticosteroids 3
• A limited trial of oral corticosteroids (30-40 mg prednisone daily for a short period) may be warranted in selected patients before eliminating asthma from consideration 1

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

• Perform induced sputum testing for eosinophils if available 1, 2
• If testing is unavailable, proceed with empiric inhaled corticosteroid treatment 1, 2, 3

Step 4: Treat Gastroesophageal Reflux Disease

• Initiate empiric GERD treatment if cough persists after addressing UACS and asthma, or if typical reflux symptoms are present 1, 2
• Begin treatment before performing esophageal testing 2

Management of Subacute Cough (3-8 Weeks)

• Determine if postinfectious or non-infectious 1, 2, 3
• For postinfectious cough, consider inhaled ipratropium as first-line therapy 1
• If ipratropium fails and cough affects quality of life, add inhaled corticosteroids 1
• For severe paroxysms, prescribe 30-40 mg prednisone daily for a short course after ruling out UACS, asthma, and GERD 1
• Consider central-acting antitussives (codeine or dextromethorphan) when other measures fail 1, 5
• If cough lasts >2 weeks with paroxysms, post-tussive vomiting, or inspiratory whooping, suspect Bordetella pertussis and obtain nasopharyngeal culture 1

When to Pursue Advanced Testing

• If cough persists after 4-6 weeks of empiric treatment for the top diagnoses, obtain high-resolution chest CT and consider bronchoscopic evaluation 1, 2
• Chest CT is indicated when clinical suspicion suggests bronchiectasis (8-12% of referral cases), interstitial lung disease (8% of cases), or occult malignancy 1, 4
• Bronchoscopy should be performed to evaluate for endobronchial tumor, sarcoidosis, suppurative infection, or eosinophilic/lymphocytic bronchitis 1

Critical Pitfalls to Avoid

• Do not rely on cough characteristics (timing, quality, productivity) for diagnosis—they have minimal diagnostic value 1, 2
• Do not treat only one cause and stop—multiple etiologies coexist in the majority of patients, requiring additive sequential therapy 1, 2, 4
• Do not label as idiopathic cough until thorough evaluation at a specialist clinic excludes uncommon causes 1, 2
• Do not use routine cough suppressants when cough clearance is physiologically important 2
• Do not forget to check medication lists for ACE inhibitors and other drug-induced causes 1

Special Population Considerations

• In immunocompromised patients, use the same initial algorithm but expand differential diagnosis based on immune defect type and severity 1, 3
• **In HIV patients with CD4+ <200 cells/μL** (or >200 with fever, weight loss, or thrush), suspect Pneumocystis pneumonia, tuberculosis, and opportunistic infections 1, 3
• In high tuberculosis prevalence areas, obtain sputum smears, acid-fast bacilli cultures, and chest radiograph 2

Referral Indications

• Refer to a specialist cough clinic when diagnosis remains unclear after completing the sequential treatment algorithm and advanced testing 1, 2
• Consider referral earlier if red flag symptoms are present: hemoptysis, weight loss, recurrent pneumonia, or persistent symptoms despite optimal treatment 6