What is the best course of treatment for a 6-year-old child with a chronic cough lasting one month, without fever and with normal lung function?

Management of Chronic Cough in a 6-Year-Old Child

For this 6-year-old with a one-month cough, no fever, and clear lungs, you should obtain a chest radiograph and spirometry (pre- and post-bronchodilator), then determine if the cough is wet/productive versus dry, as this fundamentally directs your diagnostic and treatment pathway. 1

Initial Diagnostic Approach

Mandatory First-Line Testing

• Obtain a chest radiograph as the first-line investigation for all children with chronic cough (>4 weeks duration) 1, 2
• Perform spirometry testing (pre- and post-β2 agonist) since this child is 6 years old and can reliably complete the test 1, 2
• Characterize the cough quality carefully: Is it wet/productive or dry? This is the most critical clinical distinction that determines your next steps 1, 2

Critical History Elements to Obtain

• Look for "specific cough pointers" that indicate serious underlying disease: coughing with feeding, digital clubbing, failure to thrive, hemoptysis, chest deformity 1
• Assess for pertussis features: paroxysmal cough, post-tussive vomiting, inspiratory "whoop," or known pertussis contact (even if fully vaccinated, as vaccine immunity wanes) 1, 2
• Environmental tobacco smoke exposure must be determined and addressed 1, 3
• Determine if there are any GI symptoms: recurrent regurgitation, heartburn, or epigastric pain (GERD is NOT a common cause of isolated chronic cough in children without GI symptoms) 1

Management Based on Cough Characteristics

If Wet/Productive Cough with Normal CXR and Spirometry

This suggests protracted bacterial bronchitis (PBB), which is a common and treatable cause in children: 1, 2

• Prescribe a 2-week course of antibiotics targeting Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis 1, 2
• If cough persists after the initial 2-week course, prescribe an additional 2-week course of appropriate antibiotics 2
• If cough persists beyond 4 weeks of appropriate antibiotic therapy, refer to pediatric pulmonology for further evaluation including possible flexible bronchoscopy 1, 2
• Early antibiotic intervention may prevent progression to bronchiectasis 2

If Dry Cough with Normal CXR and Spirometry

Do NOT empirically treat for asthma unless specific features are present: 1, 3

• Consider asthma ONLY if there is a history of wheeze, exertional dyspnea, or documented atopy 1, 2
• Consider testing for airway hyperresponsiveness (AHR) in this 6-year-old if asthma is clinically suspected but spirometry is normal 1
• Post-viral cough is the most likely diagnosis in community settings; 10% of children cough for >20-25 days after URTIs, and most resolve spontaneously 1
• Consider pertussis testing if there is post-tussive vomiting, paroxysmal cough, or known contact (at 4 weeks duration, serology is the appropriate test) 1, 2

What NOT to Do (Critical Pitfalls)

• Do NOT use empirical treatment for asthma, GERD, or upper airway cough syndrome unless specific clinical features of these conditions are present 1, 2, 3
• Do NOT prescribe over-the-counter cough and cold medications as they have not been shown to be effective and carry safety risks 4, 3
• Do NOT use antihistamines or dextromethorphan for cough relief, as they have minimal to no efficacy 3
• Do NOT treat for GERD when there are no GI clinical features, as GERD is not a common cause of isolated chronic cough in children 1
• Do NOT use asthma medications unless there is other evidence of asthma (recurrent wheeze, dyspnea responsive to bronchodilators) 4

Symptomatic Management While Evaluating

• Honey (for children >1 year) provides more relief than no treatment, diphenhydramine, or placebo 3
• Ensure adequate hydration to help thin secretions 4
• Teach effective cough technique: deep breath in before coughing to maximize lung volume and generate adequate expiratory force 4

Follow-Up and Re-evaluation

• Review the child if symptoms are deteriorating or not improving after 48 hours of initiated treatment 4, 3
• If empirical treatment is used based on a hypothesized diagnosis, it should be of defined limited duration (2-3 weeks) to confirm or refute the diagnosis 1, 3
• Repeat chest radiograph only if clinical status changes or new symptoms develop 2
• Address parental expectations and concerns as part of the clinical consultation 1, 3

When to Refer or Escalate

• Immediate referral if specific cough pointers are present: digital clubbing, chest deformity, growth failure, coughing with feeding 1, 2
• Refer to pediatric pulmonology if wet cough persists beyond 4 weeks of appropriate antibiotic therapy 2
• Consider flexible bronchoscopy and/or chest CT if there are specific cough pointers or failure to respond to appropriate treatment 1

The CHEST guidelines emphasize that the 4-week threshold for defining chronic cough in children (versus 8 weeks in adults) exists specifically to prevent missing important diagnoses, as chronic cough may indicate serious underlying conditions requiring systematic evaluation 2.