What are the recommended antibiotics for inpatient treatment of cellulitis?

Recommended Antibiotics for Inpatient Treatment of Cellulitis

For hospitalized patients with cellulitis, vancomycin plus either piperacillin-tazobactam or imipenem/meropenem is the recommended empiric regimen for severe infections. 1

First-Line Antibiotic Regimens Based on Severity

Severe Nonpurulent Cellulitis (with systemic signs, altered mental status, or hemodynamic instability)

• Vancomycin plus either piperacillin-tazobactam or imipenem/meropenem 1, 2
• This combination provides coverage for both MRSA and gram-negative pathogens in severely ill patients 1

Moderate Nonpurulent Cellulitis (requiring hospitalization but without severe systemic symptoms)

• IV beta-lactam antibiotics such as cefazolin or nafcillin 2
• Consider adding MRSA coverage if no clinical response to initial therapy 1, 2

Complicated Skin and Soft Tissue Infections (cSSTI)

• Vancomycin (15-20 mg/kg/dose IV every 8-12 hours) 3
• Linezolid (600 mg PO/IV twice daily) 3, 1
• Daptomycin (4 mg/kg/dose IV once daily) 3, 4
• Telavancin (10 mg/kg/dose IV once daily) 3

When to Consider MRSA Coverage

MRSA coverage should be added to the empiric regimen in the following situations:

• Purulent cellulitis 2
• Penetrating trauma 2
• Evidence of MRSA infection elsewhere 2
• Nasal colonization with MRSA 2
• Injection drug use 2
• Systemic inflammatory response syndrome 2
• Lack of response to beta-lactam therapy 1

Special Populations and Considerations

Pediatric Patients

• Vancomycin is recommended for hospitalized children with complicated skin and soft tissue infections 1
• Alternatives include clindamycin or linezolid 1
• For children with moderate to severe cellulitis, once-daily ceftriaxone (50 mg/kg) has been shown to be non-inferior to flucloxacillin 5

Streptococcal Infections

• For confirmed streptococcal skin infections, penicillin is recommended 1
• Alternatives include clindamycin, vancomycin, linezolid, daptomycin, or telavancin 1

Duration of Therapy

• 7-14 days of therapy is recommended for complicated skin and soft tissue infections 1
• Treatment should be extended if the infection has not improved within the initial treatment period 1, 2
• Treatment can be individualized based on clinical response 1

Diagnostic Considerations

• Blood cultures are recommended in hospitalized patients with cellulitis 1
• Cultures and microscopic examination of cutaneous aspirates, biopsies, or swabs should be considered in patients with:
  • Malignancy on chemotherapy 1
  • Neutropenia 1
  • Severe cell-mediated immunodeficiency 1
  • Immersion injuries 1
  • Animal bites 1

Adjunctive Measures

• Elevation of the affected area is recommended 1
• Treatment of predisposing factors such as edema or underlying cutaneous disorders 1
• Examination of interdigital toe spaces for lower-extremity cellulitis 1
• Systemic corticosteroids could be considered in nondiabetic adult patients 1, 2

Common Pitfalls and Caveats

• Overuse of broad-spectrum antibiotics when narrower coverage would suffice 6
• Failure to consider non-infectious mimics of cellulitis such as venous stasis dermatitis, contact dermatitis, or lymphedema 6
• Clindamycin may cause Clostridium difficile-associated disease more frequently compared with other agents 3
• Daptomycin should not be used as monotherapy for MRSA infections 3
• The adjunctive use of rifampin with another active drug for the treatment of SSTI is not recommended 3