What is the approach to managing a patient with acute cough?

Approach to Acute Cough

In patients with acute cough, first rule out serious life-threatening conditions like pneumonia or pulmonary embolism through focused history and chest examination, then treat the most common cause—viral upper respiratory infection—with first-generation antihistamine/decongestant combinations, which have proven efficacy in reducing cough severity and duration. 1

Initial Risk Stratification

Immediately assess for danger signs requiring urgent intervention:

• Increased respiratory rate, grunting, intercostal retractions, or cyanosis 1, 2
• Altered consciousness or complicated seizures 2
• Severe breathlessness with abnormal chest signs 1
• Significant hemoptysis or suspected foreign body aspiration (requires immediate bronchoscopy referral) 1

Obtain focused history on:

• ACE inhibitor use (discontinue immediately if present) 1
• Smoking status 1
• Recent infectious exposures or travel 2
• Presence of fever, purulent sputum, or systemic symptoms suggesting bacterial infection 1, 2

Diagnostic Approach

Order chest radiograph if pneumonia is suspected based on:

• Tachypnea, tachycardia, or dyspnea 1, 2
• Abnormal lung findings on examination (dullness to percussion, bronchial breathing, crackles) 1
• Fever with purulent sputum 1

Perform pulse oximetry to assess for hypoxemia 2

Consider microbiological studies (sputum Gram stain and culture) only if bacterial infection is strongly suspected 2

Treatment Algorithm for Acute Viral Cough

First-Line Therapy (Most Common Scenario)

For acute cough due to common cold or viral upper respiratory infection:

• Prescribe first-generation antihistamine/decongestant combination (e.g., chlorpheniramine with pseudoephedrine), which has been shown in double-blind placebo-controlled studies to decrease cough severity and hasten resolution 1, 3
• Recommend adequate fluid intake (no more than 2 liters daily) 2, 3
• Suggest honey for cough suppression in patients over 1 year of age 1, 2
• Advise paracetamol for fever management 2, 3

Important caveat: Newer non-sedating antihistamines are ineffective for acute cough and should not be used 3

Alternative Symptomatic Options

If first-line therapy is insufficient or contraindicated:

• Dextromethorphan 60 mg (maximum dose for cough reflex suppression, though most over-the-counter preparations contain subtherapeutic doses) 1, 4
• Menthol inhalation (provides acute but short-lived cough suppression) 1
• Sedative antihistamines alone (suitable for nocturnal cough) 1

Avoid codeine or pholcodine as they have no greater efficacy than dextromethorphan but carry significantly more adverse effects 1

When to Consider Antibiotics

Prescribe empiric antibiotics only if bacterial infection is strongly suspected:

• High fever (>38.5°C) with purulent sputum 3
• Clinical or radiographic evidence of pneumonia 2, 3
• Suspected pertussis with early presentation 1

Do not prescribe antibiotics for viral acute cough as they are ineffective and promote resistance 5

Antiviral Therapy

Consider oseltamivir or other antivirals for suspected influenza if:

• Severe symptoms are present 2
• Patient presents within 48 hours of symptom onset 2

Special Considerations

Acute Exacerbation of Underlying Conditions

If acute cough represents exacerbation of:

• COPD or chronic bronchitis: Consider short course (10-15 days) of systemic corticosteroids 3
• Asthma: Treat with inhaled bronchodilators and inhaled corticosteroids 1
• Allergic/irritant rhinitis: Identify and eliminate environmental triggers 1

Immunocompromised Patients

Follow the same initial algorithm but maintain broader differential diagnosis 2, 3

Use CD4+ counts to guide evaluation in HIV-infected patients 2, 3

Consider high-resolution CT and bronchoscopy if cough persists despite appropriate treatment 2, 3

Common Pitfalls to Avoid

• Do not rely on cough characteristics (productive vs. dry, paroxysmal) for diagnosis, as they lack sensitivity and specificity 1
• Do not use antibiotics empirically for viral acute cough, as this promotes resistance without benefit 5
• Do not prescribe non-sedating antihistamines, as they are ineffective for acute cough 3
• Do not use dextromethorphan in patients taking MAOIs or within 2 weeks of stopping MAOIs 4
• Do not forget to implement respiratory hygiene measures including tissue provision, hand hygiene, and maintaining 3 feet separation in waiting areas 2

When Cough Persists Beyond 3 Weeks

If acute cough persists beyond 3 weeks, reclassify as subacute cough and:

• Determine if postinfectious (treat with antihistamine/decongestant for postnasal drip or inhaled bronchodilators for bronchial hyperresponsiveness) 1, 6
• If non-postinfectious, evaluate and manage as chronic cough with systematic approach to UACS, asthma, NAEB, and GERD 1