What is the initial treatment for pediatric patients diagnosed with pneumonitis?

Initial Treatment for Pediatric Pneumonitis (Community-Acquired Pneumonia)

For children under 5 years with presumed bacterial pneumonia treated as outpatients, oral amoxicillin 90 mg/kg/day divided into 2 doses is the first-line treatment; for children 5 years and older, oral amoxicillin at the same dose (maximum 4 g/day) remains first-line, but a macrolide should be added if atypical pathogens (Mycoplasma or Chlamydophila) cannot be clinically distinguished from typical bacterial pneumonia. 1, 2

Outpatient Treatment Algorithm

Children Under 5 Years (Preschool Age)

• First-line therapy: Oral amoxicillin 90 mg/kg/day divided into 2 doses 1, 2
• Alternative: Oral amoxicillin-clavulanate (amoxicillin component 90 mg/kg/day in 2 doses) if beta-lactamase producing organisms are suspected 1
• For presumed atypical pneumonia: Oral azithromycin 10 mg/kg on day 1, followed by 5 mg/kg/day once daily on days 2-5 1, 2, 3
• Alternative macrolides: Clarithromycin 15 mg/kg/day in 2 doses for 7-14 days, or erythromycin 40 mg/kg/day in 4 doses 1

Children 5 Years and Older (School Age)

• First-line for typical bacterial pneumonia: Oral amoxicillin 90 mg/kg/day in 2 doses (maximum 4 g/day) 1, 2
• When atypical pathogens cannot be excluded: Add a macrolide to the beta-lactam antibiotic for empiric coverage 1
• First-line for presumed atypical pneumonia: Oral azithromycin 10 mg/kg on day 1 (maximum 500 mg), followed by 5 mg/kg/day once daily on days 2-5 (maximum 250 mg) 1, 2, 3
• Alternative macrolides: Clarithromycin 15 mg/kg/day in 2 doses (maximum 1 g/day), or doxycycline for children over 7 years 1

The British Thoracic Society guidelines note that macrolide antibiotics may be used as first-line empirical treatment in children aged 5 and above because Mycoplasma pneumoniae is more prevalent in this age group 1. This represents a pragmatic approach when clinical differentiation between typical and atypical pneumonia is difficult.

Inpatient Treatment Algorithm

Fully Immunized Children with Minimal Local Penicillin Resistance

• First-line: Intravenous ampicillin or penicillin G 1
• Alternatives: Ceftriaxone or cefotaxime 1
• Add vancomycin or clindamycin if community-acquired MRSA is suspected 1

Not Fully Immunized or Significant Local Penicillin Resistance

• First-line: Ceftriaxone 50-100 mg/kg/day every 12-24 hours, or cefotaxime 150 mg/kg/day every 8 hours 1
• For life-threatening infection or empyema: Third-generation cephalosporin (ceftriaxone or cefotaxime) 1

When Atypical Pathogens Are Considered

• Add a macrolide (azithromycin, clarithromycin, or erythromycin) to the beta-lactam therapy 1
• Diagnostic testing should be performed if available in a clinically relevant timeframe 1

Treatment Duration

• Uncomplicated pneumonia: 5-day course of antibiotics is sufficient 2
• Pneumonia with complications: Longer treatment of 2-4 weeks may be necessary 2
• The British Thoracic Society recommends 7-10 days for most cases, except azithromycin which is given for 5 days 1

Monitoring and Response to Therapy

Children on adequate therapy should demonstrate clinical improvement within 48-72 hours, including resolution of fever and significant reduction in respiratory symptoms 1, 4, 2. Key monitoring points include:

• If no improvement within 48-72 hours: Further investigation is required, including consideration of alternative diagnoses, resistant pathogens, or complications such as parapneumonic effusion 1
• If condition deteriorates: Immediate reevaluation with possible imaging and consideration of switching to broader-spectrum antibiotics 1

Special Considerations and Common Pitfalls

Penicillin Allergy

• Non-serious hypersensitivity (e.g., rash): Consider oral cephalosporins with substantial activity against S. pneumoniae (cefpodoxime, cefuroxime, cefprozil) under medical supervision 1, 2
• Severe Type I hypersensitivity: Use macrolides, or consider linezolid/clindamycin 1, 2

Antibiotic Resistance Concerns

The high-dose amoxicillin regimen (90 mg/kg/day) is specifically designed to overcome penicillin-resistant S. pneumoniae 1. This dosing achieves adequate drug concentrations even against strains with intermediate resistance. Avoid using trimethoprim-sulfamethoxazole or standard macrolides as monotherapy for presumed pneumococcal pneumonia due to high resistance rates 1.

Mild Illness Without Clear Bacterial Features

Young children presenting with mild symptoms of lower respiratory tract infection need not be treated with antibiotics, as viral etiologies are common 1. However, this requires careful clinical judgment and reliable follow-up.

Switching from IV to Oral Therapy

In hospitalized patients receiving intravenous antibiotics, oral treatment should be considered if there is clear evidence of improvement, typically after 48-72 hours of clinical stability 1.