What should be done for a cough persisting more than one week?

Management of Cough Lasting Over One Week

For a cough persisting more than one week, the priority is to rule out pertussis and pneumonia immediately, then provide supportive care for presumed viral bronchitis while avoiding antibiotics unless bacterial infection is confirmed. 1, 2

Immediate Red Flag Assessment

At one week duration, this represents either uncomplicated viral upper respiratory infection or acute bronchitis, but pertussis must be actively excluded, especially if any of these features are present: 2

• Paroxysmal coughing episodes (sudden, uncontrollable bursts)
• Post-tussive vomiting (vomiting triggered by cough)
• Inspiratory whooping sound (high-pitched gasp after cough)

If any pertussis features are present, obtain nasopharyngeal culture/PCR immediately and start azithromycin or clarithromycin without waiting for results, as early macrolide therapy reduces severity and prevents transmission. 2 Isolate the patient for 5 days from treatment start. 2

Assess for pneumonia by checking vital signs and lung examination: 2

• Heart rate ≥100 bpm, respiratory rate ≥24 breaths/min, or temperature ≥38°C warrant chest X-ray
• Focal consolidation findings (asymmetrical breath sounds, rales, egophony, fremitus) indicate pneumonia requiring imaging

Management at 1 Week: Acute Bronchitis

Antibiotics are explicitly contraindicated for acute viral bronchitis in otherwise healthy adults, even with purulent (colored) sputum, as green or yellow phlegm does not indicate bacterial infection. 1, 2 Most short-term coughs are viral even when producing colored mucus. 1

Recommended supportive care: 1, 2

• First-generation antihistamine/decongestant combination (e.g., brompheniramine/pseudoephedrine or chlorpheniramine/phenylephrine)
• Guaifenesin 200-400 mg every 4 hours (up to 6 times daily) to help loosen phlegm
• Honey and lemon for symptomatic relief
• Adequate hydration, rest, warm facial packs, steamy showers, sleeping with head elevated

Transition to Subacute Cough at 3 Weeks

If cough persists to 3 weeks duration, it becomes classified as subacute postinfectious cough (defined as 3-8 weeks). 3, 1 The most common causes at this stage are postinfectious cough (48.4%), upper airway cough syndrome/UACS (33.2%), and asthma (15.8%). 3

First-line treatment at 3 weeks: 1, 4, 2

• Inhaled ipratropium bromide 2-3 puffs (17-34 mcg per puff) four times daily has the strongest evidence for attenuating postinfectious cough, with response expected within 1-2 weeks

Second-line options if ipratropium fails after 1-2 weeks: 1, 4

• Add first-generation antihistamine-decongestant combination plus intranasal corticosteroid spray (fluticasone or mometasone) for upper airway symptoms
• Consider inhaled corticosteroids (fluticasone 220 mcg or budesonide 360 mcg twice daily) if quality of life is significantly affected—allow up to 8 weeks for full response
• Dextromethorphan 60 mg for maximum cough suppression, particularly for nocturnal cough

Reserve oral prednisone (30-40 mg daily for 5-10 days) only for severe paroxysms that significantly impair quality of life, and only after ruling out UACS, asthma, and GERD. 1, 4

Critical Timepoint: 8 Weeks

If cough persists beyond 8 weeks, it must be reclassified as chronic cough and requires systematic evaluation for the top three causes: 3, 1

1. Upper airway cough syndrome (UACS) from rhinosinus conditions
2. Asthma or nonasthmatic eosinophilic bronchitis
3. Gastroesophageal reflux disease (GERD)

At this point, obtain chest X-ray if not already done, and consider spirometry, exhaled nitric oxide, and blood eosinophil count. 3 Chronic cough is frequently multifactorial—partial improvement with one treatment means continuing that therapy while adding the next intervention, rather than stopping and switching. 1

Common Pitfalls to Avoid

• Do not prescribe antibiotics for postinfectious cough—they provide no benefit, contribute to resistance, and cause adverse effects. 3, 1, 2 The only exceptions are confirmed bacterial sinusitis or early pertussis infection.
• Do not fail to recognize when cough crosses the 8-week threshold, which requires reclassification and systematic workup rather than continued symptomatic treatment. 1
• Do not jump to prednisone for mild postinfectious cough—it should be reserved for severe cases that have failed ipratropium and other therapies. 1, 4
• Green sputum does not indicate bacterial infection and should not trigger antibiotic prescription. 1, 2

Follow-Up Strategy

• Schedule follow-up at 4-6 weeks after initial evaluation to reassess response to treatment. 3, 1
• Instruct patients to return immediately if fever develops, hemoptysis occurs, or symptoms worsen. 1
• Provide reassurance that postinfectious cough typically resolves spontaneously within 3-8 weeks from symptom onset. 4