How should a 3‑year‑old child with a three‑week productive (wet) cough and no fever be evaluated and managed?

Management of a 3-Year-Old with Wet Cough for 3 Weeks and No Fever

Immediate Action: Start Antibiotics Now

For a 3-year-old with a wet cough persisting 3 weeks without fever or specific warning signs, initiate a 2-week course of antibiotics targeting common respiratory bacteria (amoxicillin-clavulanate preferred) to treat presumed protracted bacterial bronchitis (PBB). 1

While the CHEST guidelines technically define chronic cough as >4 weeks, this child is approaching that threshold with a wet cough—the hallmark of bacterial bronchitis—and early treatment prevents progression to chronic suppurative lung disease. 1, 2

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Clinical Assessment Before Starting Treatment

Rule Out Red-Flag Features (Must Be Absent)

• Coughing with feeding suggests aspiration and requires immediate investigation 1, 3
• Digital clubbing indicates possible chronic lung disease or bronchiectasis 1, 3
• Failure to thrive or poor weight gain warrants further workup 3, 4
• Respiratory distress (grunting, retractions, cyanosis) requires urgent evaluation 5, 4
• Hemoptysis is a concerning sign demanding immediate investigation 3

If any of these features are present, do not simply prescribe antibiotics—refer for urgent specialist evaluation including flexible bronchoscopy and chest CT. 1

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Antibiotic Regimen

First-Line Treatment

• Amoxicillin-clavulanate for 2 weeks is the recommended first-line antibiotic, targeting the three most common pathogens: Haemophilus influenzae (most common), Streptococcus pneumoniae, and Moraxella catarrhalis 1, 2, 6
• The 2-week duration is based on high-quality RCT evidence showing number needed to treat of 3 for cough resolution 7
• Alternative antibiotics (clarithromycin, cefaclor) may be used based on local resistance patterns, but amoxicillin-clavulanate remains most commonly studied 1

If Cough Persists After 2 Weeks

• Extend antibiotics for an additional 2 weeks (total 4 weeks) if the wet cough has not completely resolved 1, 4
• Partial improvement suggests ongoing bacterial infection requiring longer treatment 1

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Follow-Up Timeline and Escalation

Reassessment at 2 Weeks

• If cough resolves completely within 2 weeks, the diagnosis is clinically-defined PBB—no further antibiotics or investigations needed 1
• If wet cough persists, extend antibiotics for another 2 weeks 1

Reassessment at 4 Weeks Total Antibiotic Treatment

If wet cough persists after 4 weeks of appropriate antibiotics, the child requires further investigation: 1

• Chest radiograph to exclude structural abnormalities, pneumonia, or bronchiectasis 1, 3
• Flexible bronchoscopy with quantitative BAL cultures to identify resistant organisms or alternative diagnoses 1
• Chest CT scan to evaluate for bronchiectasis, especially if recurrent episodes occur 1, 6
• Immunologic evaluation if recurrent infections or other immune deficiency signs present 1

Children with chronic wet cough unresponsive to 4 weeks of antibiotics have a 5.9-fold increased risk of CT-diagnosed bronchiectasis. 1

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Supportive Care Measures

• Ensure adequate hydration to thin respiratory secretions 3, 5
• Eliminate environmental tobacco smoke exposure—a critical modifiable risk factor 3, 5
• Avoid lying flat; upright positioning improves cough effectiveness 3
• Do NOT use over-the-counter cough suppressants, antihistamines, or decongestants—they lack efficacy and carry toxicity risks in young children 5, 8, 9
• Do NOT use bronchodilators or inhaled corticosteroids unless clear asthma features (wheeze, reversible obstruction) are documented 3, 5

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Critical Pitfalls to Avoid

Do Not Delay Antibiotics

• Waiting until exactly 4 weeks to start antibiotics risks progression to bronchiectasis 2, 6
• A wet cough at 3 weeks in a preschooler is PBB until proven otherwise 1, 2

Do Not Misdiagnose as Asthma

• Isolated chronic wet cough is NOT asthma—cough sensitivity and specificity for wheeze is poor 5
• Asthma requires additional features: wheeze, nocturnal symptoms, exercise intolerance, or documented reversible airway obstruction 3, 5
• The term "cough-variant asthma" should be avoided in children to prevent unnecessary long-term asthma therapy 3

Do Not Ignore Recurrences

• Recurrent PBB (>3 episodes/year) significantly increases bronchiectasis risk 6
• Children with frequent recurrences require close monitoring and consideration of chest CT 6
• Persistent H. influenzae infection is a specific risk factor for progression to bronchiectasis 6

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When Imaging Is NOT Indicated

• Do not obtain chest radiograph at 3 weeks if the child has no fever, no respiratory distress, and no specific cough pointers 5, 9
• Routine chest X-rays in uncomplicated upper respiratory infections show abnormalities in up to 97% of children who had a recent cold, making them non-specific and unhelpful 5
• Imaging becomes indicated only if cough persists beyond 4 weeks of antibiotics or red-flag features develop 1, 3

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Parental Counseling

• Explain that PBB is a bacterial infection of the airways requiring antibiotics, not a viral illness 1, 2
• Reassure that with appropriate treatment, most children achieve complete resolution within 2 weeks 1, 7
• Warn parents to return immediately if respiratory distress, high fever (≥39°C), inability to feed, or cyanosis develops 5, 4
• Emphasize the importance of completing the full 2-week antibiotic course even if cough improves earlier 1
• Address concerns about antibiotic resistance by explaining that untreated bacterial bronchitis can progress to permanent lung damage 2, 6