What is the recommended treatment for cellulitis?

Treatment for Cellulitis

The primary treatment for cellulitis is immediate antibiotic therapy targeting Gram-positive bacteria, with non-purulent cellulitis typically treated with beta-lactam antibiotics like cephalexin for 5-7 days, while purulent cellulitis requires incision and drainage plus empiric MRSA coverage. 1

Classification and Initial Assessment

Cellulitis should be classified based on severity:

• Mild: Localized infection without systemic symptoms
• Moderate: More extensive infection or with mild systemic symptoms
• Severe: Failed outpatient treatment, significant systemic illness, immunocompromised state, or signs of deeper infection 1

Warning signs requiring urgent attention:

• Pain disproportionate to physical findings
• Rapid progression
• Extensive facial involvement
• Signs of deeper infection
• Systemic toxicity 1

Treatment Algorithm

1. Determine if Purulent vs. Non-purulent

• Purulent cellulitis (with abscess):

  • Primary treatment is incision and drainage 1
  • Empiric antibiotic coverage for MRSA is recommended
  • Options include:
    • Clindamycin: 300-450 mg orally four times daily
    • Trimethoprim-sulfamethoxazole
    • Doxycycline: 100 mg orally twice daily
    • Minocycline: 200 mg loading dose, then 100 mg orally twice daily 1

• Non-purulent cellulitis:

  • Empiric coverage for β-hemolytic streptococci without MRSA coverage
  • First-line options:
    • Cephalexin
    • Penicillin
    • Amoxicillin 1, 2

2. Determine Treatment Setting (Outpatient vs. Inpatient)

Hospitalization criteria:

• Systemic signs of toxicity
• Rapid progression
• Immunocompromised state
• Significant comorbidities
• Extremes of age
• Facial involvement with concern for airway compromise
• Warning signs of necrotizing infection 1

Inpatient treatment options:

• IV Vancomycin: 15-20 mg/kg/dose every 8-12 hours
• IV Linezolid: 600 mg twice daily
• IV Daptomycin: 4 mg/kg/day
• IV Telavancin: 10 mg/kg/day 1

3. Duration of Therapy

• Standard duration: 5-7 days for uncomplicated cases 1
• Evidence shows 5 days of therapy is as effective as 10 days for uncomplicated cellulitis 3
• Extend therapy if clinical improvement is not observed within this timeframe 1

Special Considerations

Recurrent Cellulitis

For patients with 3-4 episodes per year:

• Consider prophylactic antibiotics
• Address underlying conditions:
  • Edema
  • Obesity
  • Eczema
  • Venous insufficiency 1

Adjunctive Therapy

• While some research suggests anti-inflammatory medications may hasten resolution 4, this is not included in current guidelines
• For wound infections, adjunctive therapy with aztreonam and/or metronidazole may be considered for gram-negative coverage if needed 5

Prevention

• Maintain good personal hygiene
• Keep draining wounds covered with clean, dry bandages
• Avoid reusing or sharing personal items
• Implement environmental hygiene measures 1

Common Pitfalls to Avoid

1. Misdiagnosing pseudocellulitis: Conditions like venous stasis dermatitis, contact dermatitis, and lymphedema can mimic cellulitis 2

2. Unnecessary MRSA coverage: Despite rising rates of community-acquired MRSA, coverage for non-purulent cellulitis is generally not recommended unless there are specific risk factors 2, 6

3. Excessive treatment duration: Longer courses (>5 days) have not demonstrated superior outcomes for uncomplicated cases and increase risk of adverse effects and antimicrobial resistance 1, 3

4. Missing deeper infections: Always evaluate for warning signs of necrotizing soft tissue infections, which require immediate surgical consultation 1, 7

5. Failing to monitor for complications: Watch for signs of anaphylaxis (difficulty breathing, tongue/throat swelling) and orbital involvement (proptosis, pain with eye movements, vision changes) 1