What is the initial workup and treatment for a patient presenting with a cough?

Initial Workup and Treatment for Cough

Classify Cough Duration First

Begin by classifying the cough as acute (<3 weeks), subacute (3-8 weeks), or chronic (>8 weeks), as this fundamentally determines your diagnostic and therapeutic approach. 1, 2

Initial Assessment - Key Historical Elements

Obtain a focused history targeting these specific factors:

• ACE inhibitor use - discontinue immediately if present, as this is a common reversible cause 1, 2, 3
• Smoking status - counsel on cessation, as 90-94% of smokers experience cough resolution within the first year of quitting 3
• Signs of life-threatening disease - assess for pneumonia, pulmonary embolism, or systemic illness requiring urgent intervention 1, 2
• Respiratory distress indicators - markedly elevated respiratory rate, intercostal retractions, cyanosis, or altered mental status 2
• Risk factors for complications - comorbidities, frailty, immunosuppression, or impaired cough clearance 2

Initial Diagnostic Testing

• Chest radiograph - obtain if pneumonia is suspected based on tachypnea, tachycardia, dyspnea, or abnormal lung findings 2
• Spirometry - perform as part of basic evaluation for chronic cough 4, 5
• Additional baseline tests for chronic cough: exhaled nitric oxide, blood eosinophil count, and validated cough severity/quality of life instruments 5

Management Based on Duration

Acute Cough (<3 weeks)

• For common cold: First-generation antihistamine/decongestant combination plus naproxen 2
• For acute exacerbation of chronic bronchitis: Short course (10-15 days) of systemic corticosteroids 2
• Avoid newer non-sedating antihistamines - they are ineffective for cough 2

Subacute Cough (3-8 weeks)

• Determine if postinfectious or non-infectious 1, 6
• For postinfectious cough: Consider upper airway cough syndrome (UACS), transient bronchial hyperresponsiveness, asthma, or pertussis 1, 6
• If non-infectious: Manage as chronic cough 1, 6

Chronic Cough (>8 weeks)

Use a sequential and additive treatment approach targeting the three most common causes, as multiple etiologies frequently coexist. 1, 2

Step 1: Upper Airway Cough Syndrome (UACS)

• Initial empiric treatment: Oral first-generation antihistamine/decongestant combination 1, 2, 6
• If prominent upper airway symptoms: Add topical corticosteroid 1

Step 2: Asthma

• If spirometry shows reversible airflow obstruction: Treat with inhaled bronchodilators and inhaled corticosteroids 2, 6
• If spirometry is normal: Perform bronchoprovocation challenge (BPC) when available 1
• If BPC unavailable: Empiric trial of inhaled corticosteroids and bronchodilators 1, 6
• For refractory cases: Add leukotriene receptor antagonist before escalating to oral corticosteroids 2

Step 3: Non-Asthmatic Eosinophilic Bronchitis (NAEB)

• Perform induced sputum test for eosinophils - this has important treatment implications and should be available in cough clinics 1
• If testing unavailable: Empiric trial of inhaled corticosteroids 1, 6
• Demonstration of sputum eosinophilia guides corticosteroid therapy 1

Step 4: Gastroesophageal Reflux Disease (GERD)

• Initiate empiric treatment for patients with typical reflux symptoms before performing esophageal testing 1
• No current esophageal function test predicts treatment response 1

When to Pursue Advanced Testing

If cough persists after 4-6 weeks of empiric treatment for the top diagnoses:

• High-resolution CT scan 1, 2, 5
• Bronchoscopic evaluation 1, 2
• Consider uncommon causes - including drug-induced cough, airway foreign body, tuberculosis (in high-prevalence areas), or other pulmonary/extrapulmonary causes 1, 2
• Referral to specialist cough clinic - recommended when diagnosis remains unclear 1

Critical Pitfalls to Avoid

• Do not rely on cough characteristics alone - they have little diagnostic value 1, 2
• Do not treat only one cause - multiple factors often contribute simultaneously, requiring additive therapy 1, 2
• Do not label as idiopathic until thorough assessment at a specialist clinic excludes uncommon causes 1
• Do not use routine cough suppressants when cough clearance is important 1

Special Populations

Immunocompromised Patients

• Use the same initial algorithm but expand differential diagnosis based on immune defect type and severity 1, 2
• In HIV patients with CD4+ <200 cells/μL: Suspect Pneumocystis pneumonia, tuberculosis, and opportunistic infections 1, 2

Tuberculosis Considerations

• In high-prevalence areas: Obtain sputum smears, cultures for acid-fast bacilli, and chest radiograph 1
• Do not exclude more common etiologies while evaluating for TB 1