What are the antibiotic options for nasal cellulitis to cover Methicillin-resistant Staphylococcus aureus (MRSA) and Streptococcus pyogenes in a patient with a sulfonamide (sulfa) allergy?

Antibiotic Options for Nasal Cellulitis with Sulfa Allergy

First-Line Options for MRSA and S. pyogenes Coverage

For nasal cellulitis in patients with sulfa allergy, clindamycin is the preferred first-line oral antibiotic as it provides excellent coverage for both MRSA and Streptococcus pyogenes when local resistance rates are low (<10%). 1

Outpatient Treatment Options (Oral)

For patients who can be managed as outpatients:

• Clindamycin: 300-450 mg orally three times daily for 5-10 days (A-II)

  • Advantages: Covers both MRSA and β-hemolytic streptococci as monotherapy
  • Monitor for: Clostridioides difficile-associated diarrhea

• Linezolid: 600 mg orally twice daily for 5-10 days (A-II)

  • Advantages: Excellent coverage for both pathogens as monotherapy
  • Disadvantages: High cost, risk of myelosuppression with prolonged use

• Doxycycline/Minocycline: 100 mg twice daily for 5-10 days (A-II)

  • Note: May need to combine with β-lactam (e.g., amoxicillin) for optimal streptococcal coverage
  • Contraindicated in children <8 years of age and pregnancy

Inpatient Treatment Options (IV)

For severe infections requiring hospitalization:

• IV Vancomycin: 15-20 mg/kg every 8-12 hours (A-I)

  • First-line for hospitalized patients with complicated skin infections
  • Requires monitoring of trough levels

• IV Linezolid: 600 mg twice daily (A-I)

  • Alternative when vancomycin is contraindicated

• IV Clindamycin: 600 mg every 8 hours (A-III)

  • Good option if local resistance rates are low

• Daptomycin: 4 mg/kg IV once daily (A-I)

  • Alternative for patients with vancomycin intolerance

• Telavancin: 10 mg/kg IV once daily (A-I)

  • Consider for complicated cases

Treatment Algorithm

1. Assess severity:

   • Mild-moderate (outpatient): No systemic symptoms, limited area
   • Severe (inpatient): Extensive involvement, rapid progression, systemic symptoms, immunocompromised state, or facial involvement with risk of cavernous sinus thrombosis

2. For mild-moderate nasal cellulitis:

   • Start with oral clindamycin if local resistance <10%
   • Alternative: linezolid or doxycycline (with amoxicillin if streptococcal coverage is a concern)

3. For severe nasal cellulitis:

   • Initiate IV vancomycin or linezolid
   • Consider surgical consultation if abscess is suspected

4. Duration of therapy:

   • 5-10 days for uncomplicated cases
   • Extend to 7-14 days for complicated cases
   • Individualize based on clinical response

Important Considerations

• Nasal cellulitis carries higher risk for complications including cavernous sinus thrombosis and vision loss, as documented in case reports of MRSA nasal infections 2

• Incision and drainage is the primary treatment for any purulent collections (A-II) 1

• Empiric MRSA coverage is recommended for purulent cellulitis even before culture results are available 1

• Consider obtaining cultures from purulent drainage when possible, though yield from needle aspiration of cellulitis may be low 3

• Monitor for clinical improvement within 48-72 hours; if no improvement, consider broadening coverage or surgical intervention

• While some evidence suggests streptococci are the predominant pathogens in non-purulent cellulitis 4, the nasal location and risk of MRSA warrant broader coverage initially

• Rifampin should not be used as monotherapy or adjunctive therapy for skin infections (A-III) 1