What is the antibiotic of choice for facial cellulitis?

Antibiotic of Choice for Facial Cellulitis

For facial cellulitis, the first-line antibiotic treatment is penicillin or a penicillinase-resistant penicillin (such as dicloxacillin) as these effectively target streptococci, the most common causative organism. 1, 2

Causative Organisms and Antibiotic Selection

Facial cellulitis is primarily caused by:

• Streptococcus species (most common)
• Staphylococcus aureus (particularly with abscess or penetrating trauma)

Treatment Algorithm:

1. For typical facial cellulitis (nonpurulent):

   • First-line: Penicillin V 500 mg orally four times daily for 5-7 days 2
   • Alternative: Dicloxacillin or cephalexin 500 mg orally four times daily for 5-7 days 1, 2

2. For penicillin-allergic patients:

   • Clindamycin 300-450 mg orally three times daily 2, 3
   • Macrolides (e.g., erythromycin 500 mg four times daily) 2

3. When MRSA is suspected (history of MRSA, penetrating trauma, injection drug use, or systemic inflammatory response syndrome):

   • Add coverage with trimethoprim-sulfamethoxazole, doxycycline, or linezolid 1, 2
   • For severe cases: Vancomycin IV 1

4. For severe infections requiring hospitalization:

   • IV options: Nafcillin or cefazolin 1
   • For penicillin-allergic patients: Vancomycin IV 1

Duration of Treatment

The recommended duration for antimicrobial therapy is 5 days, but treatment should be extended if the infection has not improved within this time period 1. Recent evidence supports shorter courses (5-6 days) for uncomplicated infections 2.

Supportive Measures

• Elevation of the affected area to promote drainage of edema 1, 2
• Warm compresses several times daily 2
• Identify and treat predisposing conditions 1, 2

Important Considerations

• Blood cultures are not routinely recommended for typical cases but should be considered in patients with malignancy, neutropenia, severe immunodeficiency, or systemic toxicity 1
• MRSA is an unusual cause of typical facial cellulitis. A prospective study showed that treatment with β-lactams was successful in 96% of patients with cellulitis, suggesting that MRSA coverage is usually unnecessary unless specific risk factors are present 1
• Hospitalization is recommended if there is concern for deeper infection, poor adherence to therapy, immunocompromised status, or if outpatient treatment is failing 1, 2

Common Pitfalls

• Failing to distinguish between preseptal and orbital cellulitis, which require different management approaches 2
• Unnecessary coverage for MRSA in typical community-acquired facial cellulitis without risk factors 1, 2
• Inadequate elevation of the affected area, which delays resolution 2
• Treating for too long when shorter courses are often sufficient 2

While rare cases of facial cellulitis may be caused by unusual organisms like Candida albicans 4 or Pseudomonas aeruginosa 5, these are typically associated with specific risk factors such as uncontrolled diabetes or immunosuppression and are not the primary consideration in typical cases.