What are the next steps for a child with a viral infection and a persistent cough lasting more than two weeks?

Management of Persistent Cough Beyond Two Weeks in a Child with Viral Infection

For a child with cough persisting beyond two weeks following a viral infection, evaluate for specific cough pointers (coughing with feeding, digital clubbing, chest deformity, growth failure) and assess whether the cough is wet/productive or dry. 1

Initial Assessment at Two Weeks

Determine Cough Characteristics

• Assess if the cough is wet/productive versus dry, as management pathways differ significantly 1
• Look for specific "cough pointers" that indicate serious underlying disease: coughing with feeding, digital clubbing, chest deformity, growth failure, or respiratory distress 1, 2
• Evaluate for paroxysmal cough with post-tussive vomiting or inspiratory "whoop", which suggests pertussis even in vaccinated children 1, 3

For Wet/Productive Cough Without Specific Pointers

Prescribe 2 weeks of antibiotics targeting common respiratory bacteria (Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis), such as amoxicillin-clavulanate. 1, 2 This treats protracted bacterial bronchitis, a common cause of persistent wet cough in children.

• If cough resolves within 2 weeks, the diagnosis is protracted bacterial bronchitis 2
• If cough persists after the initial 2-week course, prescribe an additional 2 weeks of antibiotics 1, 2
• If cough persists after 4 weeks total of antibiotics, proceed to flexible bronchoscopy with quantitative cultures and consider chest CT imaging 2

For Dry Cough

• Do not empirically treat with asthma medications unless there is evidence of recurrent wheeze and/or dyspnea responsive to beta-2 agonists 1
• Most children with isolated dry cough do not have asthma, and overdiagnosis should be avoided 4
• Continue observation as post-viral cough typically resolves within 3-4 weeks, though 10% may cough for >20-25 days 1

Red Flags Requiring Immediate Further Investigation

Evaluate immediately for pertussis if:

• Paroxysmal cough with post-tussive vomiting develops 1, 3
• Inspiratory "whoop" is present 3
• Known contact with pertussis case, even if child is fully vaccinated 1, 3

Other concerning features requiring urgent evaluation:

• High fever ≥39°C (102.2°F) 2
• Respiratory distress (increased respiratory rate, retractions, grunting) 2
• Any specific cough pointers mentioned above 1, 2

Critical Pitfalls to Avoid

• Do not use over-the-counter cough and cold medications (dextromethorphan, guaifenesin) in young children, as they offer no symptomatic relief and carry risk of adverse effects 5, 6, 7
• Do not dismiss persistent wet cough as "just a cold" - wet cough lasting >4 weeks requires active antibiotic management to prevent progression to bronchiectasis 2, 4
• Do not assume isolated dry cough is asthma - this leads to overdiagnosis and inappropriate treatment 4, 8
• Do not use asthma medications, hypertonic saline, or inhaled osmotic agents for post-viral cough unless clear evidence of asthma exists 1

Environmental Factors

Identify and eliminate tobacco smoke exposure, as this is a critical modifiable factor that prolongs cough 2, 8

Expected Timeline

• Most post-viral coughs resolve within 1-3 weeks 1
• 10% of children may cough for >20-25 days after viral infection 1
• Cough becomes "chronic" at 4 weeks, requiring the structured approach outlined above 1
• For pertussis, median cough duration is 29-39 days in vaccinated children and 52-61 days in unvaccinated children 1