First-Line Treatment for Facial Cellulitis
The first-line treatment for facial cellulitis is a beta-lactam antibiotic such as cephalexin (500 mg 3-4 times daily) or amoxicillin-clavulanate (875/125 mg twice daily) for a duration of 5-6 days. 1
Diagnosis Considerations
Before initiating treatment, it's important to confirm the diagnosis of facial cellulitis, which presents with:
- Rapidly spreading areas of erythema, swelling, tenderness, and warmth
- Possible "orange peel" appearance (peau d'orange) due to superficial cutaneous edema
- Possible systemic symptoms including fever, tachycardia, or leukocytosis 2, 1
For typical cases of facial cellulitis, blood cultures or tissue aspirates are unnecessary. However, these should be obtained if the patient has:
- Malignancy
- Severe systemic features
- Unusual predisposing factors
- Neutropenia or immunodeficiency 1
Treatment Algorithm
Step 1: Assess Severity
Mild to moderate (outpatient management):
- No systemic toxicity
- No rapidly progressing infection
- No concerning features for necrotizing infection
Severe (inpatient management):
- Systemic toxicity (high fever, hypotension)
- Rapidly progressing infection
- Facial cellulitis with risk of cavernous sinus thrombosis
Step 2: Select Appropriate Antibiotic Therapy
For Outpatient Treatment (Mild to Moderate):
- First-line: Beta-lactam antibiotics targeting beta-hemolytic streptococci 1
- Cephalexin: 500 mg orally 3-4 times daily for 5-6 days
- Amoxicillin-clavulanate: 875/125 mg orally twice daily for 5-6 days
- Dicloxacillin: 500 mg orally 4 times daily for 5-6 days
For Inpatient Treatment (Severe):
- First-line IV therapy 1:
- Cefazolin: 1-2g IV every 8 hours
- Oxacillin: 1-2g IV every 4-6 hours
Step 3: Reassessment
- Reassess within 48-72 hours of initiating therapy 1
- If no improvement or worsening occurs, consider:
- Changing to MRSA-active therapy
- Obtaining cultures if not done initially
- Evaluating for complications or alternative diagnoses
Special Considerations
MRSA Coverage
MRSA is an unusual cause of typical cellulitis. A study demonstrated that treatment with β-lactams was successful in 96% of patients, suggesting that cellulitis due to MRSA is uncommon 2. However, consider MRSA coverage if:
- Cellulitis is associated with penetrating trauma
- Illicit drug use history
- Purulent drainage is present
- Concurrent evidence of MRSA infection elsewhere
- Failure to respond to beta-lactam therapy within 48-72 hours 1
Options for MRSA coverage include:
- Clindamycin: 300-450 mg orally three times daily
- Doxycycline: 100 mg twice daily
- Trimethoprim-sulfamethoxazole (for purulent infections)
- For IV therapy: vancomycin, daptomycin, or linezolid 1
Duration of Therapy
A 5-day course of antimicrobial therapy is as effective as a 10-day course if clinical improvement has occurred by day 5 2, 1. Premature discontinuation can lead to treatment failure and increased risk of resistance 1.
Adjunctive Measures
- Elevation of the affected area to promote gravity drainage of edema 1
- Consider systemic corticosteroids in non-diabetic adult patients (prednisone 40 mg daily for 7 days) 1
- Some evidence suggests that adding NSAIDs (like ibuprofen 400 mg every 6 hours) may hasten resolution of inflammation 3
Pitfalls to Avoid
Failure to recognize necrotizing infections - Signs often appear late, making emergent surgical evaluation crucial if there is pain disproportionate to physical findings, violaceous bullae, skin sloughing, or rapid progression 1
Overlooking underlying predisposing conditions - Address predisposing factors to prevent recurrence 1
Inadequate coverage for facial cellulitis - Due to the risk of cavernous sinus thrombosis, facial cellulitis should be treated aggressively
Failure to drain abscesses - Antibiotics alone are insufficient for purulent collections; surgical drainage is essential 1
Misdiagnosis of cellulitis - The term "cellulitis" is not appropriate for cutaneous inflammation associated with collections of pus, such as septic bursitis or skin abscesses 2