What is the best antibiotic for facial cellulitis?

Best Antibiotic for Facial Cellulitis

For typical facial cellulitis, start with oral cephalexin 500 mg four times daily or dicloxacillin 500 mg four times daily for 5 days, targeting beta-hemolytic streptococci as the primary pathogen. 1

First-Line Treatment Algorithm

For Typical Non-Purulent Facial Cellulitis (No MRSA Risk Factors)

• Beta-lactam antibiotics active against streptococci are first-line: cephalexin, dicloxacillin, amoxicillin, or penicillin for 5 days 1, 2
• The Infectious Diseases Society of America specifically recommends cephalexin or dicloxacillin as preferred agents 2
• Extend treatment beyond 5 days only if no clinical improvement is evident 1

For Penicillin-Allergic Patients

• Clindamycin 300-450 mg orally three times daily is the preferred alternative, providing excellent coverage against both streptococci and staphylococci 2, 3
• Clindamycin is FDA-approved for serious skin and soft tissue infections caused by susceptible streptococci and staphylococci 3
• Alternative options include erythromycin or levofloxacin, though fluoroquinolones should be reserved for specific scenarios 1

When to Add MRSA Coverage

Consider empiric MRSA coverage if ANY of these risk factors are present:

• Purulent drainage or exudate from the infection site 2
• Penetrating trauma as the inciting event 1, 2
• History of MRSA infection or known nasal colonization 1, 2
• Injection drug use 1, 2
• Systemic toxicity (SIRS) or failure to respond to initial beta-lactam therapy 1, 2

MRSA-Active Regimens

• For dual coverage (streptococci + MRSA): clindamycin alone is the simplest option 1, 2
• Alternative combination therapy: trimethoprim-sulfamethoxazole (TMP-SMX) or doxycycline/minocycline PLUS amoxicillin 1, 2
• In high MRSA-prevalence areas, TMP-SMX demonstrated 91% treatment success versus 74% for cephalexin alone 4

Critical Pitfall to Avoid

Never use TMP-SMX or tetracyclines as monotherapy for non-purulent cellulitis without confirmed MRSA, as these agents lack adequate streptococcal coverage and streptococci remain the primary pathogen in typical facial cellulitis 2

Special Considerations for Facial Cellulitis

• Facial cellulitis of odontogenic origin responds well to clindamycin or ampicillin/sulbactam, as these infections are polymicrobial with aerobic and anaerobic organisms 5
• Rare cases of Neisseria meningitidis causing facial cellulitis have been reported, responding to ceftriaxone or amoxicillin 6
• Cefadroxil once daily is therapeutically equivalent to cephalexin four times daily for facial cellulitis of dental origin, offering improved compliance 7

Indications for Hospitalization and IV Therapy

Admit for IV antibiotics if:

• Signs of systemic illness or sepsis are present 2
• Rapid progression of infection despite oral therapy 2
• Immunocompromised state 2
• Failure of outpatient oral therapy 2

IV antibiotic options include: vancomycin, cefazolin, or clindamycin 600 mg IV three times daily 2

Adjunctive Measures

• Elevate the affected area to promote drainage of edema and inflammatory substances 1, 2
• Examine interdigital toe spaces for fissuring or maceration that may harbor pathogens serving as portals of entry 1, 2
• Treat predisposing conditions such as tinea pedis or other toe web abnormalities 1

Diagnostic Testing

• Do NOT routinely obtain cultures for typical non-purulent facial cellulitis, as aspiration is unhelpful in 75-80% of cases and blood cultures are positive in <5% 2
• Reserve blood cultures for patients with malignancy, severe systemic features, or unusual predisposing factors 1