Treatment of Leg Cellulitis
For non-purulent cellulitis of the leg, a 5-6 day course of beta-lactam antibiotics targeting streptococci is the recommended first-line therapy, with consideration for MRSA coverage in non-responsive cases or those with MRSA risk factors. 1
First-Line Antibiotic Therapy
Outpatient Treatment
- Beta-lactam antibiotics (first choice for non-purulent cellulitis):
- Amoxicillin-clavulanate
- Cephalexin
- Penicillin 1
Alternative Options (for penicillin allergy or suspected MRSA)
- Clindamycin 600mg orally three times daily 1
- Doxycycline (not for children <8 years) 1
- Linezolid 600mg twice daily (for severe cases or MRSA) 1
Hospitalization Criteria and IV Therapy
Consider hospitalization and IV antibiotics for:
- Severe infection
- Systemic symptoms
- Immunocompromised patients
- Failed outpatient therapy
IV Options:
- Vancomycin (first-line for hospitalized patients requiring MRSA coverage) 1
- Linezolid 600mg twice daily (90% cure rate in clinical trials) 2
- Daptomycin 4mg/kg/day IV 1, 3
- Telavancin 10mg/kg/day IV 1
Treatment Duration and Follow-up
- Treatment duration: 5-6 days for uncomplicated cases (as effective as longer courses) 1, 4
- May extend to 10 days based on clinical response 1
- Daily follow-up until definite improvement is noted 1
Management of Predisposing Factors
- Identify and treat underlying conditions:
- Edema
- Obesity
- Eczema
- Venous insufficiency
- Local trauma sites 1
Prevention of Recurrent Infections
- Maintain good personal hygiene
- Keep draining wounds covered with clean, dry bandages
- Avoid reusing or sharing personal items 1
- Consider prophylactic antibiotics for patients with 3-4 episodes per year despite treatment of predisposing factors 1
Special Considerations
Abscess Management
- For abscesses with significant cellulitis, perform incision and drainage plus antibiotic therapy 1
- Obtain cultures from abscesses and purulent drainage to guide therapy 1
Contraindications and Precautions
- Avoid tetracyclines in children under 8 years of age 1
- Do not use TMP-SMX alone for non-purulent cellulitis (poor activity against streptococci) 1
- Avoid unnecessarily prolonged antibiotic courses 1
Diabetic Foot Infections
- For diabetic foot infections with cellulitis, linezolid showed 83% cure rates in clinically evaluable patients compared to 73% with comparator treatments 2
- Consider adjunctive treatment methods such as debridement and off-loading 2
Clinical Pearls
- Venous insufficiency, eczema, deep vein thrombosis, and gout are frequently mistaken for cellulitis - ensure accurate diagnosis
- Beta-lactams remain the cornerstone of therapy due to excellent activity against streptococci, the most common cause of non-purulent cellulitis
- Shorter treatment courses (5-6 days) are as effective as longer courses for uncomplicated cases, reducing antibiotic exposure and potential resistance