What is the treatment for a 9-month-old with a 2-week cough?

Management of 2-Week Cough in a 9-Month-Old

For a 9-month-old with a 2-week cough, provide supportive care only and reassess at 4 weeks if the cough persists—do not prescribe over-the-counter cough medications, antibiotics, or asthma medications at this stage. 1, 2

Immediate Management (Weeks 1-4)

This represents a subacute cough (between acute and chronic), most commonly following a viral upper respiratory infection. 3 The critical threshold for chronic cough in children is 4 weeks, so this child has not yet reached that point. 4, 1

Supportive Care Measures

• Maintain adequate hydration through continued breastfeeding or formula to help thin secretions 2
• Use saline nasal drops to relieve nasal congestion that may contribute to post-nasal drip and cough 2
• Elevate the head of the crib during sleep to improve comfort and breathing 2
• Minimize environmental irritants, particularly tobacco smoke exposure and other pollutants 2, 3

What NOT to Prescribe

• Do not use over-the-counter cough and cold medications in children under 6 years—they lack efficacy and carry risk of serious adverse events 4, 1, 2
• Do not prescribe codeine-containing medications due to potential for respiratory distress 4, 2
• Do not prescribe antibiotics at this stage—a 2-week cough without specific features does not warrant antibiotics 1, 2
• Do not prescribe asthma medications unless other features of asthma are present (recurrent wheeze, dyspnea, family history of atopy) 1, 2

Expected Clinical Course

• Most viral-associated coughs resolve within 7-10 days, with 90% of children cough-free by day 21 2, 3
• This represents either post-viral cough or acute bronchitis, both self-limited conditions 2

Red Flags Requiring Immediate Return

Instruct parents to return immediately if any of the following develop:

• Respiratory distress (increased work of breathing, retractions, grunting) 2
• Fever develops 2
• Oxygen saturation drops below 92% 2
• Paroxysmal cough with post-tussive vomiting or inspiratory "whoop" (suggests pertussis) 2, 3
• Inability to feed or signs of dehydration 2

Reassessment at 4 Weeks

If the cough persists beyond 4 weeks, the child must be re-evaluated to identify specific etiological pointers and determine the next management step. 4, 1

Determine Cough Characteristics at 4 Weeks

If the cough is WET/PRODUCTIVE at 4 weeks:

• Initiate a 2-week course of antibiotics targeting common respiratory bacteria (Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis) 4, 1, 2
• Amoxicillin-clavulanate is the most commonly used first-line antibiotic 4, 5
• This treats protracted bacterial bronchitis (PBB), the most common cause of chronic wet cough in young children 4, 5
• If cough resolves within 2 weeks of antibiotics, the diagnosis of PBB is confirmed 4
• If cough persists after 2 weeks, extend antibiotics for an additional 2 weeks 4

If the cough is DRY at 4 weeks:

• This is termed "non-specific cough"—continue watchful waiting as most resolve spontaneously 4, 2
• Consider a trial of inhaled corticosteroids (400 mcg/day beclomethasone equivalent) for 2-4 weeks only if risk factors for asthma are present (family history of atopy, personal history of eczema, recurrent wheeze) 4, 1
• Re-evaluate in 2-4 weeks after any intervention 4

Special Considerations for This Age Group

Pertussis Evaluation

• Consider pertussis if the cough pattern changes to paroxysmal episodes with post-tussive vomiting or inspiratory "whoop," especially if vaccination status is incomplete 2, 3
• Pertussis is highly contagious with 80% secondary attack rate in susceptible contacts 3
• Obtain nasopharyngeal aspirate or swab for culture/PCR if pertussis is suspected 3

Specific Cough Pointers to Assess

Look for these features that would warrant immediate investigation rather than waiting 4 weeks: 4

• Feeding difficulties or coughing with feeding (suggests aspiration)
• Failure to thrive or poor weight gain
• Abnormal breath sounds on auscultation (crackles, wheeze, stridor)
• History of choking episode (suggests foreign body aspiration)
• Digital clubbing (suggests chronic lung disease)
• Chest wall deformity or respiratory distress

Common Pitfalls to Avoid

• Over-diagnosing asthma in infants with isolated cough—asthma is difficult to diagnose reliably at 9 months of age 2, 6
• Prescribing empirical asthma medications without evidence of airway obstruction or risk factors 1, 2
• Using antibiotics prematurely before the cough becomes chronic (>4 weeks) or wet/productive 1, 2
• Treating empirically for GERD without gastrointestinal symptoms (recurrent regurgitation, heartburn)—acid suppression should not be used solely for chronic cough 4, 1

Parent Education

• Explain this is likely a self-limited viral illness that will resolve in the coming weeks 2, 3
• Provide clear instructions on warning signs requiring immediate return 2
• Emphasize hand hygiene and avoiding contact with sick individuals 2
• Reassure that no medication is needed or beneficial at this stage—supportive care is the appropriate evidence-based approach 1, 2
• Schedule follow-up at 4 weeks if the cough persists to reassess and determine if further evaluation or treatment is needed 4, 1, 3