What are the best antibiotic options for a patient with recurrent nose cellulitis, possibly due to Methicillin-resistant Staphylococcus aureus (MRSA), who was previously treated with Bactrim (Trimethoprim/Sulfamethoxazole) approximately 45 days ago?

Recurrent Nasal Cellulitis with Possible MRSA: Antibiotic Options After Bactrim Failure

For recurrent nasal cellulitis with suspected MRSA involvement that has returned after Bactrim treatment 45 days ago, switch to clindamycin 300-450 mg orally every 6 hours for 5-10 days if local MRSA resistance is <10%, or use vancomycin 15-20 mg/kg IV every 8-12 hours if systemic signs are present. 1, 2

Critical Assessment Before Choosing Antibiotics

Determine if this is true recurrence versus treatment failure:

• Recurrence at the same site suggests local factors such as foreign material, chronic colonization, or inadequate decolonization rather than antibiotic resistance 1
• Purulent drainage or fluctuance mandates incision and drainage as primary treatment—antibiotics alone will fail 1
• Systemic signs (fever >38°C, tachycardia, hypotension, altered mental status) require hospitalization and IV therapy 1, 3

Antibiotic Selection Algorithm

For Outpatient Management (No Systemic Toxicity)

First-line option: Clindamycin monotherapy

• Clindamycin 300-450 mg orally every 6 hours for 5-10 days provides single-agent coverage for both streptococci and MRSA 1, 3, 2
• Use only if local MRSA clindamycin resistance rates are <10%—verify this with your microbiology lab 3, 2
• This avoids the need for combination therapy and covers both likely pathogens 3, 2

Alternative oral regimens if clindamycin resistance is high:

• Doxycycline 100 mg twice daily PLUS cephalexin 500 mg four times daily for dual MRSA and streptococcal coverage 3, 2
• Minocycline 200 mg loading dose, then 100 mg twice daily may be more effective than doxycycline or TMP-SMX for CA-MRSA skin infections 2, 4
• Do NOT use TMP-SMX (Bactrim) again as monotherapy—it already failed and lacks reliable streptococcal coverage 3, 2

For Inpatient Management (Systemic Signs Present)

Vancomycin remains the gold standard:

• Vancomycin 15-20 mg/kg IV every 8-12 hours targeting trough concentrations of 15-20 mg/L 3, 2
• Alternative IV options: linezolid 600 mg IV twice daily or daptomycin 4 mg/kg IV once daily 3, 2
• For severe infection with systemic toxicity: vancomycin PLUS piperacillin-tazobactam 3.375-4.5 g IV every 6 hours 1, 3, 2

Addressing Recurrence: Decolonization Strategy

Since this infection has returned after 45 days, implement a 5-day decolonization regimen:

• Intranasal mupirocin 2% ointment twice daily for 5 days 1
• Daily chlorhexidine body washes during the 5-day period 1
• Daily decontamination of personal items including towels, sheets, razors, and any items that contact the nose 1
• Consider repeating this regimen monthly for 3-6 months if recurrences continue 1

Critical caveat: Evidence for decolonization effectiveness in the current CA-MRSA era is limited, but it remains a reasonable strategy for recurrent infections 1

Treatment Duration

• Treat for 5 days if clinical improvement occurs (warmth, tenderness resolving, erythema improving) 1, 3
• Extend beyond 5 days only if symptoms have not improved within this timeframe 1, 3
• For recurrent infections, consider 7-10 days total to ensure adequate eradication 1, 3

Common Pitfalls to Avoid

• Do not repeat Bactrim (TMP-SMX) monotherapy—it failed once and lacks streptococcal coverage 3, 2, 5
• Do not use doxycycline alone—its activity against beta-hemolytic streptococci is unreliable 3, 2
• Do not add rifampin—resistance develops rapidly and there is no evidence of benefit for skin infections 2
• Do not assume this is simple cellulitis—nasal location raises concern for abscess requiring drainage 1

When to Escalate Care

Hospitalize immediately if any of the following develop:

• Fever, hypotension, or altered mental status 1, 3
• Rapid progression or severe pain out of proportion to examination 1, 3
• Extension to periorbital area or signs of orbital involvement 6
• Failure to improve after 48 hours of appropriate outpatient antibiotics 3

Special Consideration for Nasal Location

Nasal cellulitis warrants heightened concern because:

• The nose is a common site of MRSA colonization, increasing recurrence risk 1
• Proximity to facial danger zones (cavernous sinus) makes progression potentially catastrophic 6
• Purulent collections in this area may be difficult to detect clinically—consider imaging if not improving 1