What is the recommended dose for cellulitis treatment?

Recommended Antibiotic Dosing for Cellulitis Treatment

For typical non-purulent cellulitis in adults, the standard dosing regimen is cephalexin 500 mg four times daily (every 6 hours) for 5 days, with extension if the infection has not improved within this time period. 1, 2

First-Line Treatment Options

Non-Purulent Cellulitis (Most Common)

• Cephalexin 500 mg orally four times daily (every 6 hours) is the standard regimen for typical cellulitis caused by streptococci 1, 3
• Alternative dosing: 500 mg every 12 hours may be used for skin and skin structure infections 3
• Duration: 5 days is recommended, with extension if infection has not improved 2, 1
• For severe infections, dosage may be doubled (up to 4g daily total) 3

Purulent Cellulitis (Associated with drainage/exudate)

• Empirical coverage for CA-MRSA is recommended pending culture results 2
• Options include:
  • Clindamycin 600 mg orally three times daily 2
  • Trimethoprim-sulfamethoxazole (TMP-SMX) 2
  • Tetracycline (doxycycline or minocycline) 2
  • Linezolid 600 mg twice daily 2

Treatment Considerations Based on Severity

Mild Cellulitis (Outpatient)

• No systemic signs of infection, no altered mental status, hemodynamically stable 2
• Oral antibiotics targeting streptococci (cephalexin) are appropriate 1
• Recent evidence suggests high-dose cephalexin (1000 mg four times daily) may have fewer treatment failures than standard dose, though with more minor adverse effects 4

Moderate to Severe Cellulitis (Consider Hospitalization)

• For hospitalized patients with complicated skin infections 2:
  • IV vancomycin 2
  • IV/oral linezolid 600 mg twice daily 2
  • IV daptomycin 4 mg/kg once daily 2
  • IV telavancin 10 mg/kg once daily 2
  • IV/oral clindamycin 600 mg three times daily 2

Special Situations Requiring MRSA Coverage

• Cellulitis associated with:
  • Penetrating trauma 2, 1
  • Evidence of MRSA infection elsewhere 1, 5
  • Nasal colonization with MRSA 2
  • Injection drug use 2, 5
  • Systemic inflammatory response syndrome (SIRS) 2

Adjunctive Measures

• Elevation of the affected area to reduce edema 2, 5
• Treatment of predisposing factors (edema, obesity, eczema, venous insufficiency) 2
• Examination of interdigital toe spaces in lower-extremity cellulitis 2, 1
• For non-diabetic patients, systemic corticosteroids (prednisone 40 mg daily for 7 days) could be considered 2, 5

Common Pitfalls to Avoid

• Don't extend treatment unnecessarily beyond 5 days if clinical improvement has occurred 1, 5
• Don't automatically add MRSA coverage for typical non-purulent cellulitis without specific risk factors 1, 6
• Don't overlook the importance of treating underlying conditions that may predispose to recurrent cellulitis 2, 1
• Don't forget to consider high-dose cephalexin (1000 mg four times daily) in areas with high treatment failure rates 4

Prevention of Recurrence

• For patients with 3-4 episodes per year, consider prophylactic antibiotics 2:
  • Oral penicillin or erythromycin twice daily for 4-52 weeks 2
  • Intramuscular benzathine penicillin every 2-4 weeks 2
• Continue prophylaxis as long as predisposing factors persist 2