What is the recommended treatment for cellulitis?

Treatment of Cellulitis

The recommended first-line treatment for uncomplicated cellulitis is a 5-day course of antibiotics active against streptococci and Staphylococcus aureus, with extension if the infection has not improved within this time period. 1

Antibiotic Selection for Outpatient Treatment

• For typical cases without systemic signs of infection, antimicrobial agents active against streptococci are recommended, including:

  • Penicillin
  • Amoxicillin
  • Amoxicillin-clavulanate
  • Dicloxacillin
  • Cephalexin
  • Clindamycin 1

• When MRSA is a concern, consider:

  • Trimethoprim-sulfamethoxazole
  • Clindamycin
  • Linezolid 1

• In areas with high MRSA prevalence, trimethoprim-sulfamethoxazole has shown significantly higher success rates (91%) compared to cephalexin (74%) 2

• For diabetic patients with mild to moderate infections, broader coverage including both streptococci and S. aureus is recommended with options such as:

  • Amoxicillin-clavulanate
  • Trimethoprim-sulfamethoxazole
  • Clindamycin 1

Severe Cellulitis (Inpatient Treatment)

• For patients with systemic signs of infection, intravenous antibiotics are recommended 1

• Initial empiric therapy should include:

  • Vancomycin
  • Linezolid
  • Daptomycin
  • Telavancin
  • Ceftaroline (when MRSA risk factors are present) 1

• For severe cellulitis with skin sloughing or concern for necrotizing infection, broader coverage with vancomycin plus piperacillin-tazobactam or a carbapenem is recommended 1

Duration of Therapy

• The recommended initial duration is 5 days, with extension if the infection has not improved within this time period 1, 3

• For severe infections with skin sloughing, longer courses (10-14 days) may be necessary based on clinical response 1

• Evaluation of response should occur every 2-5 days initially for outpatients 1

Adjunctive Measures

• Elevation of the affected area to promote drainage of edema and inflammatory substances is recommended 1

• Identification and treatment of predisposing factors such as edema, obesity, eczema, venous insufficiency, and toe web abnormalities is recommended 1

• Systemic corticosteroids could be considered in non-diabetic adult patients to reduce inflammation 1

• Some evidence suggests that adding an oral non-steroidal anti-inflammatory agent (like ibuprofen) to antibiotic therapy may hasten resolution of cellulitis-related inflammation 4

Hospitalization Criteria

• Severe infections with systemic inflammatory response syndrome (SIRS) require hospitalization 1

• Altered mental status or hemodynamic instability require hospitalization 1

• Concern for deeper or necrotizing infection requires hospitalization 1

Prevention of Recurrence

• For patients with 3-4 episodes of cellulitis per year despite treatment of predisposing factors, prophylactic antibiotics should be considered 1, 5

• Options include:

  • Oral penicillin or erythromycin twice daily for 4-52 weeks
  • Intramuscular benzathine penicillin every 2-4 weeks 1

• This prophylactic program should continue as long as predisposing factors persist 1

Special Considerations

• The majority of cellulitis cases (approximately 85%) are nonculturable, but when organisms are identified, most are due to β-hemolytic Streptococcus and Staphylococcus aureus 3

• Risk factors for treatment failure include therapy with an antibiotic that is not active against community-associated MRSA and severity of cellulitis 2

• Blood cultures should be obtained in patients with severe systemic features, malignancy, or unusual predisposing factors 1

• For surgical site infections, suture removal plus incision and drainage should be performed 1

• Common risk factors for cellulitis include prior episodes of cellulitis, cutaneous lesions, tinea pedis, and chronic edema 5

• Addressing predisposing factors can minimize risk of recurrence 3