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

Management of Cough

The management of cough depends critically on its duration: classify as acute (<3 weeks), subacute (3-8 weeks), or chronic (>8 weeks), then apply a systematic, sequential approach targeting the most common causes while immediately addressing reversible factors like ACE inhibitors and smoking. 1

Initial Assessment for All Cough Presentations

Begin by identifying immediately reversible causes and life-threatening conditions:

• Discontinue ACE inhibitors immediately if the patient is taking them, as this is a common and completely reversible cause of cough 2, 1
• Counsel and assist with smoking cessation in all smokers, as 90-94% experience cough resolution within the first year of quitting 1
• Assess for life-threatening conditions including pneumonia, pulmonary embolism, or systemic illness requiring urgent intervention 2, 1
• Look for respiratory distress indicators: markedly elevated respiratory rate, intercostal retractions, cyanosis, or altered mental status 1, 3
• Identify risk factors for complications: comorbidities, frailty, immunosuppression, or impaired cough clearance 1, 3
• Obtain a chest radiograph if pneumonia is suspected based on tachypnea, tachycardia, dyspnea, or abnormal lung findings 1, 3

Note that cough characteristics (timing, quality, sound) have little diagnostic value and should not guide your workup. 2, 1

Acute Cough (<3 Weeks)

For acute cough, first rule out serious illness (pneumonia, pulmonary embolism), then treat the most common cause—viral upper respiratory infection:

• For common cold with cough, prescribe a first-generation antihistamine/decongestant combination plus naproxen, which has been shown in double-blind placebo-controlled studies to decrease cough severity and hasten resolution 2, 1, 3
• Do not use newer-generation non-sedating antihistamines, as they are ineffective for cough 3
• For acute exacerbation of chronic bronchitis, prescribe a short course (10-15 days) of systemic corticosteroids 1, 3
• Consider environmental or occupational exposures to noxious or irritating agents (allergic or irritant-induced rhinitis) 2

Subacute Cough (3-8 Weeks)

For subacute cough, determine if it is postinfectious or not—this distinction drives management:

• If postinfectious (following an obvious respiratory infection), consider upper airway cough syndrome (UACS), transient bronchial hyperresponsiveness, asthma, pertussis, or acute exacerbation of chronic bronchitis 2, 1
• If non-infectious or unclear, manage as chronic cough using the algorithm below 2, 4
• For suspected UACS, start a first-generation antihistamine/decongestant combination 4
• For suspected asthma or bronchial hyperresponsiveness, use inhaled bronchodilators and inhaled corticosteroids 4
• Consider pertussis in the differential, especially if cough persists beyond 2 weeks with paroxysmal features 5

Chronic Cough (>8 Weeks)

For chronic cough, use a sequential and additive treatment approach targeting the three most common causes, which frequently coexist: upper airway cough syndrome (UACS), asthma, and gastroesophageal reflux disease (GERD). 2, 1

Step 1: Treat Upper Airway Cough Syndrome (UACS)

• Start with an oral first-generation antihistamine/decongestant combination as initial empiric treatment 2, 1
• Add a topical nasal corticosteroid if prominent upper airway symptoms are present 1
• Continue treatment for at least 2-4 weeks before moving to the next step 1

Step 2: Evaluate and Treat Asthma

• If UACS treatment fails, evaluate for asthma next 2
• Medical history is suggestive but not reliable for ruling asthma in or out 2
• Perform spirometry first; if it shows reversible airflow obstruction, treat with inhaled bronchodilators and inhaled corticosteroids 1
• If spirometry is normal, perform bronchoprovocation challenge (BPC) ideally 2, 1
• If BPC is unavailable, initiate an empiric trial of inhaled corticosteroids and bronchodilators 2, 1
• Consider adding a leukotriene receptor antagonist for refractory cases before escalating to oral corticosteroids 1, 3

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

• If UACS and asthma have been eliminated or treated without resolution, consider NAEB 2
• Perform induced sputum test for eosinophils if available 2, 1
• If testing is unavailable, initiate empiric treatment with inhaled corticosteroids 2, 1

Step 4: Treat Gastroesophageal Reflux Disease (GERD)

• Initiate empiric treatment with a proton pump inhibitor (PPI) plus diet/lifestyle modifications for patients with typical reflux symptoms 1
• GERD treatment should be added to, not substituted for, other partially effective treatments 1

Critical Management Principles for Chronic Cough

Therapy must be given in sequential and additive steps because more than one cause is frequently present simultaneously. 2, 1

• Do not discontinue partially effective treatments—maintain all therapies that provide some benefit while adding new treatments 1
• Optimize therapy for each diagnosis and check compliance before declaring treatment failure 1
• Allow adequate time for response (typically 4-6 weeks per intervention) 1

When to Pursue Advanced Testing

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

• Consider high-resolution CT scan of the chest 1, 4
• Consider bronchoscopic evaluation for uncommon causes 1, 4
• Refer to a specialist cough clinic when diagnosis remains unclear 1
• Do not label as idiopathic until thorough assessment at a specialist clinic excludes uncommon causes 1

Special Populations

Immunocompromised Patients

• Use the same initial algorithm but expand the differential diagnosis based on immune defect type and severity 1, 3
• In HIV patients with CD4+ <200 cells/μL, suspect Pneumocystis pneumonia, tuberculosis, and opportunistic infections 1
• In high-prevalence areas, obtain sputum smears, cultures for acid-fast bacilli, and chest radiograph to evaluate for tuberculosis 1

Common Pitfalls to Avoid

• Do not rely on cough characteristics (timing, quality, sound) for diagnosis—they lack sensitivity and specificity 2, 1
• Do not treat only one cause—multiple factors often contribute simultaneously, requiring additive therapy 2, 1
• Do not use routine cough suppressants when cough clearance is important for secretion management 1
• Do not use dextromethorphan if the patient has chronic cough with excessive phlegm, asthma, or emphysema, or if cough persists beyond 7 days 6
• Do not use antibiotics for acute bronchitis in patients without chronic lung disease, as it is usually viral and antibiotics provide minimal benefit (reducing cough by only half a day) while causing adverse effects 7