What is the recommended treatment for cellulitis?

Cellulitis Treatment

The recommended first-line treatment for uncomplicated cellulitis is a 5-day course of antibiotics active against streptococci, such as penicillin, amoxicillin, amoxicillin-clavulanate, dicloxacillin, cephalexin, or clindamycin. 1

Antibiotic Selection

• For typical non-purulent cellulitis, use antibiotics active against streptococci (penicillin, amoxicillin, amoxicillin-clavulanate, dicloxacillin, cephalexin, or clindamycin) 1, 2
• For moderate infections with systemic signs, consider coverage for both streptococci and methicillin-susceptible S. aureus (MSSA) 1, 2
• MRSA coverage is generally unnecessary for typical cellulitis but should be considered in specific situations: 1
  • Cellulitis associated with penetrating trauma 2
  • Purulent drainage 2
  • Concurrent evidence of MRSA infection elsewhere 2
  • History of injection drug use 2
  • Athletes, children, men who have sex with men, prisoners, military recruits, residents of long-term care facilities 3

Duration of Therapy

• A 5-day course of antibiotics is as effective as a 10-day course if clinical improvement occurs by day 5 1, 4
• Extend treatment if infection has not improved within the initial 5-day period 5, 2

Treatment Setting

• Outpatient therapy is appropriate for patients without SIRS, altered mental status, or hemodynamic instability 1, 2
• Hospitalization is recommended for: 1, 5, 2
  • Concern for deeper or necrotizing infection
  • Poor adherence to therapy
  • Infection in severely immunocompromised patients
  • Failure of outpatient treatment
  • Severe infections with systemic inflammatory response syndrome
  • Altered mental status
  • Hemodynamic instability

Adjunctive Measures

• Elevate the affected area to promote gravity drainage of edema and inflammatory substances 1, 2
• Identify and treat predisposing conditions: 1, 2
  • Tinea pedis
  • Trauma
  • Venous eczema
  • Venous insufficiency
  • Lymphedema
  • Toe web abnormalities
• Consider systemic corticosteroids in non-diabetic adult patients to reduce inflammation 1, 2

Prevention of Recurrence

• For patients with 3-4 episodes of cellulitis per year despite treatment of predisposing factors, consider prophylactic antibiotics 1, 2
• Options for prophylaxis include oral penicillin, erythromycin, or intramuscular benzathine penicillin 2

Special Considerations for Preseptal Cellulitis

• Treatment follows the same principles as standard cellulitis 5
• Identify and treat predisposing factors such as sinusitis 5

Common Pitfalls to Avoid

• Don't extend treatment unnecessarily beyond 5 days if clinical improvement has occurred 2
• Don't automatically add MRSA coverage for typical non-purulent cellulitis without specific risk factors 2
• Don't forget to examine interdigital toe spaces in lower-extremity cellulitis 2
• Don't overlook the importance of elevating the affected area, especially in patients with venous insufficiency or lymphedema 2

Specific Antibiotic Dosing

• For adults and adolescents (≥12 years): 600 mg linezolid IV or oral q12h for 10-14 days 6
• For pediatric patients: 10 mg/kg linezolid IV or oral q8h 6
• For uncomplicated skin infections in adults: 400 mg linezolid oral q12h 6
• For uncomplicated skin infections in adolescents: 600 mg linezolid oral q12h 6