What is the recommended treatment for a staff member with a skin infection likely caused by Staphylococcus aureus, considering severity and underlying conditions like diabetes or compromised immune system?

Treatment of Staphylococcus aureus Skin Infections in Staff Members

For staff members with suspected S. aureus skin infections, treatment depends critically on whether the infection is purulent (abscess/furuncle) or non-purulent (cellulitis), the severity of systemic involvement, and the patient's immune status—with incision and drainage being the primary treatment for any purulent collection, and antibiotic selection guided by infection severity and MRSA risk factors. 1

Initial Assessment and Diagnostic Approach

Determine Infection Type and Severity

Purulent infections (abscesses, furuncles, carbuncles):

• Incision and drainage is the definitive primary treatment and may be sufficient alone for simple abscesses without systemic signs 1
• Cultures are not routinely recommended for simple purulent infections 1
• However, blood cultures ARE recommended and tissue cultures should be strongly considered in staff with diabetes, immunocompromise, chemotherapy, neutropenia, or severe cell-mediated immunodeficiency 1

Non-purulent infections (cellulitis):

• Blood cultures are recommended for moderate-to-severe cases 1
• Tissue cultures should be considered in immunocompromised patients 1

Antibiotic Treatment Algorithm

For Purulent Infections (Abscesses/Furuncles)

Mild cases without systemic signs:

• Incision and drainage alone is often sufficient 1
• No antibiotics needed if no fever, limited surrounding cellulitis, and normal immune function 1

Moderate cases with systemic signs (fever, tachycardia >90, tachypnea >24, WBC >12,000 or <4,000):

• Oral antibiotics active against MRSA are recommended 1
• Preferred options:
  • Trimethoprim-sulfamethoxazole 1-2 double-strength tablets twice daily 1
  • Doxycycline 100 mg twice daily (avoid if age <8 years) 1
  • Clindamycin 300-450 mg three times daily (if local resistance <10-15%) 1

Severe cases or immunocompromised patients (diabetes, etc.):

• IV antibiotics required 1
• Vancomycin 15-20 mg/kg every 8-12 hours IV 1
• Alternative: Linezolid, daptomycin, or ceftaroline 1

For Non-Purulent Infections (Cellulitis)

Mild cellulitis without systemic signs:

• Antibiotic active against streptococci is the primary recommendation 1
• Cephalexin 500 mg every 6 hours orally 1, 2
• Alternative: Penicillin VK 250-500 mg every 6 hours orally 1
• Clindamycin 300-450 mg three times daily if penicillin allergic 1

Moderate cellulitis with systemic signs:

• Many clinicians should include coverage against MSSA 1
• Cefazolin 1 g every 8 hours IV 1
• Nafcillin 1-2 g every 4-6 hours IV 1

Severe cellulitis or high MRSA risk (penetrating trauma, known MRSA colonization, injection drug use, purulent drainage, SIRS criteria):

• Vancomycin or another agent effective against both MRSA and streptococci is strongly recommended 1
• Vancomycin 15-20 mg/kg every 8-12 hours IV 1

Severely compromised patients (diabetes with poor control, chemotherapy, neutropenia):

• Broad-spectrum coverage should be considered 1
• Vancomycin PLUS piperacillin-tazobactam or imipenem/meropenem 1

Treatment Duration and Monitoring

• Standard duration is 5 days, but extend if infection has not improved within this timeframe 1
• For recurrent abscesses after drainage and culture, treat with a 5-10 day course of an antibiotic active against the isolated pathogen 1

Special Considerations for Healthcare Staff

Recurrent S. aureus Infections

If staff member has recurrent abscesses:

• Drain and culture early in the course 1
• Search for local causes (pilonidal cyst, hidradenitis suppurativa, foreign material) 1
• Consider a 5-day decolonization regimen 1:
  • Intranasal mupirocin twice daily 1, 3
  • Daily chlorhexidine body washes 1
  • Daily decontamination of personal items (towels, sheets, clothes) 1

Hospitalization Criteria

Outpatient treatment is appropriate for staff without SIRS criteria, altered mental status, or hemodynamic instability 1

Hospitalization is recommended for 1:

• Concern for deeper or necrotizing infection
• SIRS criteria present
• Severely immunocompromised status
• Failing outpatient treatment

Adjunctive Measures

• Elevation of the affected extremity to reduce edema 1, 4
• Treatment of predisposing factors such as edema, obesity, eczema, venous insufficiency 1
• For lower extremity infections, carefully examine interdigital toe spaces for fungal infection that may serve as portal of entry 1, 4

Critical Pitfalls to Avoid

• Do not rely on antibiotics alone for purulent collections—incision and drainage is essential and often sufficient 1
• Do not assume MSSA in staff with diabetes, immunocompromise, or healthcare exposure—these patients need MRSA coverage 1
• Do not use cephalosporins in patients with immediate penicillin hypersensitivity (urticaria, angioedema, bronchospasm, anaphylaxis) 5
• Do not use tetracyclines (doxycycline, minocycline) in children under 8 years 1
• Avoid mupirocin for systemic infections—it is FDA-approved only for topical treatment of impetigo 3 and should not be used as monotherapy for deeper infections