What is the recommended treatment for cellulitis?

Cellulitis Treatment

The recommended first-line treatment for cellulitis is a 5-6 day course of antibiotics targeting beta-hemolytic streptococci and Staphylococcus aureus, with options including cephalexin (500 mg 3-4 times daily), clindamycin (300-450 mg three times daily), or amoxicillin-clavulanate (875/125 mg twice daily). 1

Antibiotic Selection Algorithm

1. For uncomplicated cellulitis (no abscess, no MRSA risk factors):

   • First-line: Cephalexin 500 mg 3-4 times daily for 5-6 days 1
   • Alternative: Amoxicillin-clavulanate 875/125 mg twice daily for 5-6 days 1

2. For penicillin-allergic patients:

   • Clindamycin 300-450 mg orally three times daily for 5-6 days 1
   • Doxycycline 100 mg twice daily 1
   • Combination of sulfamethoxazole-trimethoprim (160-800 mg twice daily) plus metronidazole (250-500 mg three times daily) 1

3. When MRSA is suspected (>10-15% prevalence in area or specific risk factors):

   • Trimethoprim-sulfamethoxazole
   • Clindamycin
   • Doxycycline 1

Management of Abscesses

• Incision and drainage is the primary treatment for abscesses, with antibiotics as adjunctive therapy 1
• For complicated skin and soft tissue infections with abscess formation, antimicrobial therapy should cover both beta-hemolytic streptococci and community-acquired MRSA 1

Treatment Duration and Monitoring

• Standard duration: 5-6 days for uncomplicated infections 1
• Monitor for improvement within 72 hours; if no improvement is seen, reevaluate and consider changing antibiotic therapy 1
• Treatment may need to be extended if infection has not improved within 5-7 days 1

Hospitalization Criteria

Consider inpatient management with IV antibiotics for:

• Severe infections or systemic symptoms
• Concern for deeper or necrotizing infection
• Immunocompromised patients
• Failed outpatient treatment
• Poor adherence to therapy 1

Special Considerations

• Recent antibiotic exposure: Patients who have received antibiotics in the previous 4-6 weeks should be given an alternative class or higher-dose regimen 1
• Immunocompromised patients: May require broader coverage and longer duration of therapy 1
• Underlying conditions: Identify and treat predisposing conditions such as edema, obesity, eczema, venous insufficiency, and toe web abnormalities 1

Common Pitfalls to Avoid

1. Misdiagnosis: Venous insufficiency, eczema, deep vein thrombosis, and gout are frequently mistaken for cellulitis 2
2. Inadequate coverage: Failing to cover the most common pathogens (beta-hemolytic streptococci and S. aureus) 3
3. Overlooking abscesses: Not recognizing when surgical drainage is needed in addition to antibiotics 1
4. Premature discontinuation: Stopping antibiotics before adequate clinical improvement 1
5. Failure to recognize necrotizing infections: These require immediate surgical intervention 3

Prevention of Recurrence

• Maintain good hand hygiene practices
• Avoid trauma to skin
• Keep skin clean and dry
• Promptly treat minor skin breaks
• Daily change of socks and careful drying between toes after showers 1

The evidence strongly supports a short course (5-6 days) of targeted antibiotic therapy for most cases of cellulitis, with clinical response guiding any need for extension or change in therapy. While newer antibiotics like tedizolid have shown efficacy in clinical trials 4, traditional options remain first-line due to their proven effectiveness, safety profile, and cost-effectiveness.