What are the treatment recommendations for pediatric pneumonia caused by Streptococcus (Streptococcus) versus Staphylococcus (Staphylococcus) aureus, including Methicillin-resistant Staphylococcus aureus (MRSA)?

Treatment Recommendations for Pediatric Pneumonia: Streptococcus vs. Staphylococcus aureus

For pediatric pneumonia, amoxicillin is the first-line treatment for Streptococcus pneumoniae, while Staphylococcus aureus infections, particularly MRSA, require addition of vancomycin or clindamycin to beta-lactam therapy. 1, 2

General Treatment Approach Based on Suspected Pathogen

Streptococcus pneumoniae

• Outpatient treatment (children <5 years): Oral amoxicillin 90 mg/kg/day in 2 doses 1, 2
• Outpatient treatment (children ≥5 years): Oral amoxicillin 90 mg/kg/day in 2 doses (maximum 4 g/day) 1, 2
• Inpatient treatment (fully immunized children): Ampicillin or penicillin G IV; alternatives include ceftriaxone or cefotaxime 1
• Inpatient treatment (not fully immunized): Ceftriaxone or cefotaxime IV 1
• Duration: 5-day course is as effective as 10-day course for uncomplicated pneumonia 3

Staphylococcus aureus (Methicillin-Susceptible/MSSA)

• Outpatient treatment: Oral amoxicillin-clavulanate (amoxicillin component 90 mg/kg/day in 2 doses) 1, 2
• Inpatient treatment: Cefazolin 150 mg/kg/day divided into three doses (every 8 hours) 4, 5
• Alternative inpatient treatment: Oxacillin or ceftaroline 5

Methicillin-Resistant Staphylococcus aureus (MRSA)

• Outpatient treatment (suspected CA-MRSA): Add clindamycin (30-40 mg/kg/day in 3-4 doses) to beta-lactam therapy 2
• Inpatient treatment (suspected CA-MRSA): Add vancomycin or clindamycin to beta-lactam therapy 1
• For confirmed MRSA pneumonia: Linezolid is recommended (10 mg/kg every 8 hours for children) 6, 5
• Alternative for confirmed MRSA: Vancomycin with consideration of adding clindamycin or rifampicin, especially in PVL-positive cases 5, 7

Treatment Algorithm Based on Clinical Scenario

Outpatient Management

1. Initial Assessment:

   • Determine likelihood of typical bacterial vs. atypical pneumonia based on clinical presentation 1, 2
   • Check immunization status for Haemophilus influenzae type b and Streptococcus pneumoniae 8

2. Empiric Treatment:

   • Presumed Streptococcus pneumoniae: Amoxicillin 90 mg/kg/day in 2 doses 1, 2
   • Suspected Staphylococcus involvement: Amoxicillin-clavulanate (amoxicillin component 90 mg/kg/day in 2 doses) 1, 2
   • Suspected MRSA: Consider adding clindamycin to beta-lactam therapy 2

3. Follow-up:

   • Reassess within 48-72 hours; if no improvement, consider hospitalization or change in antibiotics 2, 8

Inpatient Management

1. Initial Assessment:

   • Obtain appropriate cultures (blood, respiratory specimens) 5
   • Assess for risk factors for MRSA (concurrent influenza, hemoptysis, multilobar infiltrates) 5

2. Empiric Treatment:

   • Fully immunized, low risk for MRSA: Ampicillin or penicillin G 1
   • Not fully immunized or high risk for MRSA: Ceftriaxone or cefotaxime plus vancomycin or clindamycin 1
   • Confirmed MRSA: Linezolid (10 mg/kg every 8 hours) 6, 5

3. Treatment Adjustment:

   • Modify therapy based on culture results and clinical response 1
   • Consider drainage for significant parapneumonic effusions 1

Key Considerations and Pitfalls

• Dosing Considerations: Higher doses of amoxicillin (90 mg/kg/day) are recommended to overcome potential resistance in pneumococci 2, 9

• Treatment Duration: A 5-day course of antibiotics is sufficient for uncomplicated pneumonia with good clinical response 3, 8

• Common Pitfalls:

  • Underdosing amoxicillin (using 40-45 mg/kg/day instead of recommended 90 mg/kg/day) 2, 9
  • Inappropriate use of macrolides as first-line therapy for presumed bacterial pneumonia 2
  • Failure to consider MRSA in patients with severe pneumonia, especially with risk factors 5
  • Not reassessing patients who fail to improve within 48-72 hours 2, 8

• Special Situations:

  • For patients with drug allergies to first-line agents, treatment should be based on the severity of the allergy and the suspected pathogen 1
  • In cases of pleural effusion, obtain pleural fluid for Gram stain and culture 1