What is the recommended management for cellulitis?

Cellulitis Management

For typical cellulitis, a 5-day course of antibiotics active against streptococci is recommended as first-line therapy, with extension if the infection has not improved within this time period. 1, 2

Diagnosis

• Cellulitis presents with rapidly spreading areas of erythema, swelling, tenderness, and warmth, sometimes accompanied by lymphangitis and regional lymph node inflammation 3
• The skin may have an orange peel appearance (peau d'orange) due to superficial cutaneous edema 3
• Diagnosis is primarily clinical - cultures of blood, tissue aspirates, or skin biopsies are unnecessary for typical cases 3, 4
• Blood cultures should be obtained for patients with malignancy, severe systemic features, or unusual predisposing factors 3

First-Line Antibiotic Selection

• For non-purulent, uncomplicated cellulitis, use oral antibiotics active against streptococci 3, 2:
  • Penicillin
  • Amoxicillin
  • Amoxicillin-clavulanate
  • Dicloxacillin
  • Cephalexin (500 mg four times daily)
  • Clindamycin

Duration of Therapy

• A 5-day course of antimicrobial therapy is as effective as a 10-day course if clinical improvement occurs by day 5 3, 2
• Treatment should be extended if the infection has not improved within the initial 5-day period 1, 2

When to Consider MRSA Coverage

• MRSA is an unusual cause of typical cellulitis 3
• Consider MRSA coverage only in specific situations 2:
  • Cellulitis associated with penetrating trauma, especially from illicit drug use
  • Evidence of purulent drainage
  • Concurrent evidence of MRSA infection elsewhere
  • History of injection drug use
  • Athletes, children, men who have sex with men, prisoners, military recruits, residents of long-term care facilities, and those with prior MRSA exposure 4

MRSA Treatment Options

• If MRSA coverage is needed, options include 3:
  • Intravenous: vancomycin, daptomycin, linezolid, or telavancin
  • Oral: doxycycline, clindamycin, or trimethoprim-sulfamethoxazole (TMP-SMX)
  • For coverage of both streptococci and MRSA: clindamycin alone or combination of TMP-SMX or doxycycline with a β-lactam

Adjunctive Measures

• Elevation of the affected area to promote drainage of edema 2
• Identify and treat predisposing factors such as tinea pedis, toe web abnormalities, venous insufficiency, and prior trauma 2
• Consider systemic corticosteroids (prednisone 40 mg daily for 7 days) in non-diabetic adults to reduce inflammation 2
• Anti-inflammatory therapy may hasten resolution of cellulitis-related inflammation 5

Hospitalization Criteria

• Consider hospitalization for patients with 2:
  • Severe infections with systemic inflammatory response syndrome
  • Altered mental status
  • Hemodynamic instability
  • Concern for deeper or necrotizing infection
  • Poor adherence to therapy
  • Immunocompromise
  • Failure of outpatient treatment

Prevention of Recurrence

• For patients with frequent episodes of cellulitis, consider prophylactic antibiotics 1, 2:
  • Oral penicillin
  • Erythromycin
  • Intramuscular benzathine penicillin
• Address underlying conditions that predispose to recurrence 2, 6:
  • Treat tinea pedis
  • Manage venous insufficiency and lymphedema

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 3, 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
• Don't miss the diagnosis of necrotizing soft tissue infections, which require urgent surgical intervention 7