What is the recommended treatment for a 3-month-old infant with a cold and cough?

Management of Cold and Cough in a 3-Month-Old Infant

Do not prescribe over-the-counter cough and cold medications to this infant, as they are contraindicated under 6 months of age due to lack of efficacy and serious risk of toxicity and death. 1, 2

Immediate Assessment for Serious Illness

Before recommending supportive care only, you must rule out conditions requiring specific treatment:

Evaluate for Pertussis (Whooping Cough)

• Look specifically for: paroxysmal coughing fits, post-tussive vomiting (vomiting after cough), or inspiratory whoop 1
• If pertussis is suspected clinically, start azithromycin immediately without waiting for culture confirmation 3
• Azithromycin is the preferred first-line agent for infants <1 month and 1-5 months due to significantly lower risk of infantile hypertrophic pyloric stenosis compared to erythromycin 4, 3
• Dosing: 10 mg/kg/day for 5 days 3
• Early treatment (within first 2 weeks) rapidly clears bacteria, decreases coughing paroxysms, and reduces life-threatening complications 3

Assess for Bacterial Pneumonia

• Red flag symptoms requiring immediate evaluation: respiratory rate >70 breaths/minute, grunting, cyanosis, oxygen saturation <92%, difficulty breathing, poor feeding, or rectal temperature ≥100.4°F (38°C) 1
• If bacterial pneumonia is suspected based on clinical findings (focal crackles, increased work of breathing, hypoxia), amoxicillin is first-choice for children under 5 years 1
• Do not prescribe antibiotics for viral upper respiratory infections, which represent the vast majority of coughs and colds 1

Supportive Care Measures (For Uncomplicated Viral URI)

Once serious bacterial infection is ruled out, recommend these evidence-based supportive measures:

• Gentle nasal suctioning to clear secretions and improve breathing 1
• Maintain adequate hydration through continued breastfeeding or formula feeding to thin secretions 1
• Supported sitting position during feeding and rest to help expand lungs and improve respiratory symptoms 1
• Acetaminophen (weight-based dosing) for fever and discomfort, which can help reduce coughing episodes 1

Critical Safety Warnings

• Never use: over-the-counter cough and cold medications (antihistamines, decongestants, antitussives, expectorants) in infants under 6 months 1, 2
• Between 1969-2006, there were 43 deaths from decongestants in infants under 1 year and 41 deaths from antihistamines in children under 2 years 1
• Never use honey in infants under 12 months due to botulism risk 1
• Avoid codeine-containing medications due to potential for serious respiratory distress 1
• Topical decongestants should not be used in infants under 1 year due to narrow therapeutic window and risk of cardiovascular and CNS toxicity 1

Follow-Up Considerations

• If cough persists beyond 4 weeks, transition to systematic chronic cough evaluation including chest radiograph 1
• Specific cough pointers to evaluate: coughing with feeding, digital clubbing, failure to thrive 1
• For chronic wet cough without specific pointers, consider 2-week trial of antibiotics targeting Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis 1

Prevention Strategies

• Emphasize hand hygiene with soap and water to prevent transmission 1
• Minimize exposure to tobacco smoke and environmental irritants 1
• Ensure household contacts are up-to-date on pertussis vaccination, as infants under 6 months are at highest risk for severe pertussis complications and death 1