Management of Productive Cough
Immediate Duration-Based Triage
For productive cough, the critical first step is determining duration: acute cough (<4 weeks) requires only supportive care as it is typically viral, while chronic wet/productive cough (>4 weeks) warrants a 2-week antibiotic trial targeting common respiratory bacteria (Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis). 1, 2
Acute Productive Cough (<4 weeks)
Supportive Care Only
- Do NOT prescribe antibiotics for acute productive cough with clear/transparent sputum, as this represents viral infection 2
- Provide adequate hydration to thin secretions, saline nasal drops for nasal congestion, and elevate the head of bed during sleep 2
- Avoid over-the-counter cough medications in children under 6 years due to lack of efficacy and potential harm 2
- Guaifenesin may help loosen phlegm and thin bronchial secretions to make coughs more productive 3
Chronic Wet/Productive Cough (>4 weeks)
Step 1: Screen for "Specific Cough Pointers"
Before initiating empiric antibiotics, assess for red flags that indicate underlying disease requiring immediate investigation rather than antibiotic trial 1, 2:
- Coughing with feeding (suggests aspiration)
- Digital clubbing (suggests bronchiectasis, cystic fibrosis)
- Failure to thrive
- Hemoptysis
- Chronic purulent sputum (always pathological)
If ANY specific cough pointers are present, proceed directly to investigations (flexible bronchoscopy, chest CT, aspiration assessment, immunologic evaluation) WITHOUT empiric antibiotic trial. 1, 2
Step 2: Antibiotic Algorithm (When No Specific Pointers Present)
Week 0-2: Initial Antibiotic Trial
- Prescribe 2 weeks of antibiotics targeting common respiratory bacteria (S. pneumoniae, H. influenzae, M. catarrhalis) based on local antibiotic sensitivities 1
- This is a Grade 1A recommendation (strongest evidence level) 1
Week 2 Assessment:
- If cough resolves: Diagnose as Protracted Bacterial Bronchitis (PBB) 1
- If wet cough persists: Extend antibiotics for an additional 2 weeks 1
Week 4 Assessment:
- If wet cough persists after 4 weeks total of appropriate antibiotics: Proceed to further investigations (flexible bronchoscopy with quantitative cultures and sensitivities with or without chest CT) 1
Step 3: Microbiological Confirmation (When Available)
- If lower airway sampling (BAL or sputum) confirms clinically important density of respiratory bacteria (≥10⁴ cfu/mL), use the term "microbiologically-based-PBB" (PBB-micro) to differentiate from clinically-based-PBB 1
Critical Pitfalls to Avoid
- Never treat GERD empirically in children with isolated chronic cough without gastrointestinal symptoms, as GERD is rarely the cause of isolated pediatric chronic cough 2
- Do not use combination antihistamine-decongestant products in children under 6 years due to lack of efficacy and potential harm 2
- Do not delay investigation if chronic purulent sputum is present, as this is always pathological and suggests bronchiectasis, cystic fibrosis, or aspiration requiring immediate comprehensive evaluation 2
- Do not rely solely on cough characteristics for diagnosis, as they have limited diagnostic value 4
Special Clinical Scenarios
Pertussis (Whooping Cough)
- If paroxysmal cough with post-tussive vomiting or inspiratory "whoop" develops, treat immediately with macrolide antibiotic and isolate for 5 days 2
Age Considerations
- These recommendations apply to children ≤14 years, excluding premature infants and neonates who typically present with tachypnea and dyspnea rather than cough 1, 2
Adult Productive Cough
- In adults with chronic productive cough, consider bronchiectasis, chronic bronchitis, asthma, eosinophilic bronchitis, and immunodeficiency as primary differential diagnoses 5
- Low-dose macrolide therapy may be effective for idiopathic chronic productive cough in adults (adult version of PBB) 5