What is the treatment for a Staphylococcus aureus (S. aureus) skin infection in a child?

Treatment of Staphylococcus aureus Skin Colonization/Infection in Children

For minor staphylococcal skin infections in children such as impetigo and secondarily infected skin lesions, topical mupirocin 2% ointment is the first-line treatment, applied twice daily for 5-10 days. 1, 2

Initial Assessment and Culture Strategy

Before initiating treatment, determine the clinical presentation:

• Simple colonization (positive swab without infection): Generally does not require treatment unless recurrent infections occur 1
• Minor localized infection (impetigo, small infected lesions): Topical therapy is appropriate 1
• Purulent infection with abscess: Incision and drainage is primary treatment, with antibiotics added for extensive disease, systemic symptoms, or high-risk features 1
• Cellulitis or deeper infection: Systemic antibiotics are required 1

Obtain cultures from purulent lesions if systemic antibiotics will be used, if there are signs of systemic illness, or if initial treatment fails. 1

Topical Treatment for Minor Infections

Mupirocin 2% ointment applied twice daily for 5-10 days is FDA-approved and guideline-recommended for impetigo and minor staphylococcal skin infections in children. 1, 2

Important caveat: Mupirocin resistance is increasingly common, with rates up to 31% reported in some pediatric populations, particularly in children with prior mupirocin exposure, atopic dermatitis, or MRSA colonization. 3 If the infection fails to respond within 3-4 days, consider resistance and switch to systemic therapy. 4, 3

Systemic Antibiotic Therapy

When systemic antibiotics are indicated (extensive infection, systemic symptoms, failed topical therapy):

For Outpatient Oral Therapy:

First-line for methicillin-susceptible S. aureus (MSSA):

• Cephalexin (first-generation cephalosporin): 25-50 mg/kg/day divided into 3-4 doses 5, 6
• Alternative: Cefadroxil or other first-generation cephalosporins 6

For empiric coverage when MRSA is suspected (purulent drainage, known MRSA colonization, failed beta-lactam therapy):

• Clindamycin: 30-40 mg/kg/day divided into 3 doses (maximum 1.8 g/day) - ONLY if local resistance rates are <10% 1, 7
• Trimethoprim-sulfamethoxazole (TMP-SMX): 8-12 mg/kg/day (based on trimethoprim component) divided into 2 doses 1
• Doxycycline or minocycline: 100 mg twice daily - contraindicated in children <8 years of age 1, 7

Duration: 5-10 days based on clinical response 1, 8

For Hospitalized Children Requiring IV Therapy:

For complicated skin and soft tissue infections:

• Vancomycin: 15 mg/kg/dose IV every 6 hours (for MRSA or critically ill patients) 1, 7
• Clindamycin: 10-13 mg/kg/dose IV every 6-8 hours (40 mg/kg/day total) - only if stable, no bacteremia, and local resistance <10% 1, 7
• Linezolid: 10 mg/kg/dose IV/PO every 8 hours for children <12 years; 600 mg twice daily for ≥12 years 1, 7
• Cefazolin: 33 mg/kg/dose every 8 hours (for MSSA or nonpurulent cellulitis) 1

Duration: 7-14 days based on clinical response 1

Critical Pitfalls to Avoid

• Never use tetracyclines (doxycycline, minocycline) in children <8 years of age due to tooth discoloration risk 1, 7
• Do not use TMP-SMX as monotherapy for cellulitis without purulent drainage, as it lacks activity against group A Streptococcus 1
• Avoid clindamycin empirically if local resistance rates exceed 10% due to risk of treatment failure from inducible resistance 1, 7
• Do not use rifampin as monotherapy or adjunctive therapy for skin infections 1
• Be aware of mupirocin resistance, especially with prior mupirocin use, MRSA infection, or atopic dermatitis 3

Decolonization for Recurrent Infections

If recurrent S. aureus infections occur despite optimal wound care:

Decolonization regimen (after treating active infection):

• Intranasal mupirocin 2% twice daily for 5-10 days 1
• Plus chlorhexidine body washes daily for 5-14 days or dilute bleach baths 1
• Plus decontamination of personal items (towels, sheets, clothing) 1

Consider screening and treating household contacts if ongoing transmission occurs despite hygiene measures. 1

Hygiene and Prevention Measures

Essential infection control practices:

• Keep draining wounds covered with clean, dry bandages 1
• Regular handwashing with soap and water or alcohol-based gel 1
• Avoid sharing personal items (razors, towels, linens) 1
• Clean high-touch surfaces with appropriate disinfectants 1
• Athletes should not return to sports for at least 24 hours after starting antibiotics 1