What is the recommended treatment for a patient with an existing Ear, Nose, and Throat (ENT) infection who is also colonized with Methicillin-resistant Staphylococcus aureus (MRSA)?

Treatment of ENT Infections in Patients Colonized with MRSA

For patients with an existing ENT infection who are also colonized with MRSA, treatment should include appropriate antibiotics that cover both the primary pathogen causing the ENT infection and MRSA, with vancomycin or linezolid being the preferred agents for severe infections. 1

Antibiotic Selection Based on Severity

Mild to Moderate ENT Infections

• First-line treatment:
  • For non-severe infections where MRSA is not the primary pathogen: Continue treatment for the underlying ENT infection
  • If MRSA is suspected as the causative agent:
    • Clindamycin 300-450 mg orally four times daily (adults) or 10-13 mg/kg/dose every 8 hours (children) if local resistance <10% 1, 2
    • Trimethoprim-sulfamethoxazole 1-2 double-strength tablets twice daily 1
    • Doxycycline 100 mg twice daily (not for children <8 years) 1

Severe ENT Infections

• First-line treatment:
  • Vancomycin 15-20 mg/kg IV every 8-12 hours (target trough 15-20 mg/mL) 1, 2
  • Linezolid 600 mg IV/PO twice daily (adults) or 10 mg/kg every 8 hours (children <12 years) 1, 2
  • Daptomycin 6 mg/kg IV daily (some experts recommend 8-10 mg/kg for severe infections) 1
  • Ceftaroline 600 mg IV twice daily 1

Special Considerations for ENT-Specific MRSA Infections

For MRSA Otitis Media/Externa

• Topical options (when tympanic membrane is intact):
  • Mupirocin aqueous solution 3, 4
  • Non-ototoxic antiseptics: Burow's solution, povidone-iodine, or acetic acid solutions 3
  • Avoid aminoglycoside drops due to ototoxicity risk

For MRSA Sinusitis

• Systemic therapy as outlined above
• Consider adjunctive measures:
  • Saline irrigations with or without antiseptics
  • Surgical drainage for complicated cases with abscess formation

For MRSA Pharyngeal Carriage/Infection

• Combination therapy is superior:
  • Rifampin-based regimen (rifampin plus clindamycin or trimethoprim-sulfamethoxazole) for 7 days 5
  • Nasal mupirocin ointment twice daily for 5-10 days 1, 5

Duration of Therapy

• Uncomplicated ENT infections: 5-10 days 1, 2
• Complicated infections (with abscess, osteomyelitis): 2-6 weeks depending on extent 1, 2
• Monitor clinical response within 72 hours of initiating therapy 2

Source Control Measures

• Surgical drainage of abscesses or collections is essential 1, 2
• Debridement of necrotic tissue when present 2
• Removal of infected foreign bodies (e.g., ear tubes, nasal packing) 2

Decolonization Strategies

For patients with recurrent MRSA ENT infections, consider decolonization:

1. Nasal decolonization:

   • Mupirocin 2% ointment applied to nares twice daily for 5-10 days 1

2. Body decolonization:

   • Chlorhexidine body washes daily for 5-14 days 1, 2
   • Alternative: Dilute bleach baths (1 teaspoon per gallon of water) for 15 minutes twice weekly 1

3. Environmental measures:

   • Clean high-touch surfaces with appropriate disinfectants 1
   • Launder clothing, towels, and bedding in hot water 2
   • Avoid sharing personal items 1, 2

Monitoring and Follow-up

• Obtain follow-up cultures 48-72 hours after initiating therapy if no clinical improvement 2
• For persistent or recurrent infections, consider:
  • Alternative antibiotics based on susceptibility testing
  • Extended decolonization protocols
  • Evaluation for underlying anatomical abnormalities or immunodeficiency

Pitfalls to Avoid

• Treating MRSA colonization without active infection (not recommended) 1
• Using single-agent oral antibiotics (like rifampin) for MRSA treatment (resistance develops rapidly) 1, 6
• Failing to obtain adequate source control through drainage or debridement 1, 2
• Inadequate dosing of vancomycin (monitor trough levels) 2
• Overlooking pharyngeal carriage, which is more difficult to eradicate than nasal carriage 5

For ENT infections with MRSA involvement, a combination of appropriate systemic antibiotics, topical treatments, and decolonization strategies offers the best chance for clinical cure and prevention of recurrence.