What is the recommended treatment for Methicillin-resistant Staphylococcus aureus (MRSA) infections in children?

Treatment of MRSA Infections in Children

For pediatric MRSA infections, IV vancomycin is the first-line treatment for serious infections, while clindamycin (if local resistance <10%) or trimethoprim-sulfamethoxazole can be used for stable patients without bacteremia, and incision and drainage alone is often sufficient for uncomplicated skin abscesses <5 cm. 1

Treatment by Infection Type and Severity

Minor Localized Skin Infections (Impetigo, Small Patches)

• Topical mupirocin 2% ointment applied three times daily for 5-10 days is the treatment of choice for minor, localized superficial infections without deeper tissue involvement, purulent drainage, or systemic illness 2
• Keep affected areas covered with clean, dry bandages and practice regular handwashing 2

Uncomplicated Skin and Soft Tissue Infections/Abscesses

Incision and drainage is the mainstay of therapy - antibiotics are adjunctive 3, 4

For abscesses <5 cm in immunocompetent children, incision and drainage alone without antibiotics is effective management 4

Add antibiotics if any of the following are present: 3

• Severe or extensive disease involving multiple sites
• Rapid progression with associated cellulitis
• Signs of systemic illness (fever, tachycardia, hypotension)
• Immunosuppression or comorbidities (diabetes, HIV)
• Extremes of age
• Difficult-to-drain locations (face, hand, genitalia)
• Lack of response to drainage alone

Oral antibiotic options for outpatient treatment (5-10 days): 1, 2, 3

• Clindamycin 10-13 mg/kg/dose IV every 6-8 hours (40 mg/kg/day total) - covers both MRSA and streptococci as monotherapy, but only use if local clindamycin resistance rate is <10% 1, 3
• Trimethoprim-sulfamethoxazole (TMP-SMX) 4 mg/kg/dose (TMP component) twice daily - excellent MRSA coverage but requires addition of amoxicillin for streptococcal coverage 1, 3
• Linezolid: 600 mg PO/IV twice daily for children >12 years; 10 mg/kg/dose every 8 hours for children <12 years - covers both MRSA and streptococci but significantly more expensive 1, 3

Serious/Invasive Infections (Bacteremia, Pneumonia, Osteomyelitis)

IV vancomycin is the first-line treatment 1

• Dose: 30-60 mg/kg/day IV divided every 6-12 hours following standard institutional protocols 1, 5
• Monitor vancomycin trough levels targeting 15-20 mcg/mL for serious infections 1, 5
• The efficacy and safety of targeting higher trough concentrations in children requires additional study but should be considered in those with severe sepsis or persistent bacteremia 1

Alternative IV options: 1, 6

• Daptomycin: 6 mg/kg/day IV once daily for skin/soft tissue infections; higher doses may be needed for bacteremia 1, 6
• Linezolid: 600 mg PO/IV twice daily for children >12 years; 10 mg/kg/dose every 8 hours for children <12 years 1

Specific Infection Types

Bacteremia (uncomplicated): 1

• Minimum 2 weeks of IV vancomycin or daptomycin
• Obtain follow-up blood cultures 2-4 days after initial positive cultures to document clearance 1

Bacteremia (complicated): 1

• 4-6 weeks of therapy depending on extent of infection
• Conduct clinical assessment to identify and eliminate/debride source 1

Osteomyelitis: 1

• Surgical debridement and drainage is the mainstay of therapy 1
• Minimum 8-week course of antibiotics 1
• IV vancomycin or daptomycin 6 mg/kg/dose IV once daily 1
• Some experts recommend adding rifampin 600 mg daily after clearance of bacteremia 1
• Typical duration: 4-6 weeks for osteomyelitis 1

Septic Arthritis: 1

• Drainage or debridement of joint space should always be performed 1
• Minimum 3-4 weeks of therapy 1
• In children, surgical debridement of hips is recommended; arthrocentesis may be adequate for other joints 1

Pneumonia with empyema: 1

• IV vancomycin with drainage procedures 1

CNS infections (meningitis): 1

• IV vancomycin for 2 weeks 1
• Some experts recommend adding rifampin 1

Critical Management Principles

Source control is essential: 1, 5

• Drainage of abscesses
• Removal of central venous catheters
• Debridement of osteomyelitis or necrotic tissue
• For CNS shunt infections, shunt removal is recommended and should not be replaced until CSF cultures are repeatedly negative 1

Monitor clinical response within 48-72 hours of initiating therapy and adjust antibiotics based on culture and susceptibility results 2, 5

Confirm susceptibility: When an alternative to vancomycin is considered, in vitro susceptibility should be confirmed and documented 1

Common Pitfalls and Caveats

Clindamycin resistance: The most critical pitfall is using clindamycin when local resistance rates are ≥10% or unknown - in these situations, choose TMP-SMX or doxycycline/minocycline instead 1, 3

Inadequate drainage: Remember that for abscesses, antibiotics are adjunctive - inadequate drainage is a common cause of treatment failure 3, 4

Premature antibiotic discontinuation: Patients with lesions >5 cm are at significantly higher risk for hospitalization and treatment failure 4

Streptococcal coverage: TMP-SMX and doxycycline/minocycline do not cover streptococci - add a beta-lactam like amoxicillin if streptococcal coverage is needed 1, 3

Daptomycin limitations: Daptomycin is not indicated for pneumonia and has not been studied in patients with prosthetic valve endocarditis 6

Age restrictions: Daptomycin is not recommended in children <1 year of age due to risk of effects on muscular, neuromuscular, and/or nervous systems 6