Treatment of Pseudomonas and Staphylococcus Infections Between Toes
For Pseudomonas and Staphylococcus infections between the toes, oral levofloxacin alone is generally sufficient for mild to moderate infections without adding topical antimicrobials, as current evidence does not support routine adjunctive topical therapy. 1
Evidence Against Routine Topical Antimicrobial Addition
The most recent and authoritative guidelines (IWGDF/IDSA 2023) explicitly recommend against using topical antibiotics in combination with systemic antibiotics for treating foot infections in patients with diabetes. 1 This recommendation is based on:
Limited clinical benefit: Studies addressing topical antibiotics as adjunctive treatment to systemic therapy have provided conflicting results with high risk of bias, inconsistency, and low certainty of evidence. 1
Theoretical concerns: While topical therapy can deliver high local concentrations, it carries risks including hypersensitivity reactions, limited effectiveness for infection in surrounding intact tissue, and potentially lower threshold for antimicrobial resistance development. 1
Mixed trial results: One trial of topical gentamicin-collagen sponge added to levofloxacin showed significantly lower cure rates at day 7 (the primary outcome), though rates improved at later follow-up. 1 This inconsistent benefit does not support routine use.
When Oral Levofloxacin Alone Is Appropriate
Oral levofloxacin monotherapy is suitable for:
Mild to moderate infections in patients without gastrointestinal absorption problems and where an appropriate oral agent is available. 1
Pseudomonas coverage: Levofloxacin demonstrates good activity against Pseudomonas aeruginosa (75.3% susceptibility), comparable to ciprofloxacin. 2
Staphylococcus coverage: Levofloxacin has broad-spectrum activity against both Gram-positive cocci including Staphylococcus species and Gram-negative organisms. 3, 4
Limited Exceptions for Topical Consideration
The 2012 IDSA guidelines suggest topical antimicrobial therapy may be considered only for:
Selected mild superficial infections with minimal cellulitis in open wounds. 1
Very limited data support this approach, and it should not be routine practice. 1
Key Clinical Caveats
Important considerations when using levofloxacin for this indication:
Ensure adequate wound care: Proper cleansing, debridement of necrotic tissue, and off-loading of pressure are crucial adjuncts to antibiotic therapy. 1
Monitor for resistance: While Pseudomonas resistance to fluoroquinolones remains relatively low in most settings, resistance can develop during therapy, particularly in compromised hosts. 1, 5
Duration of therapy: For mild soft tissue infections, 1-2 weeks is typically sufficient; moderate infections may require 2-3 weeks. 1
Assess infection severity: If the infection is severe (deep abscess, extensive tissue involvement, systemic toxicity), parenteral therapy and surgical consultation are indicated rather than oral therapy alone. 1
Bottom Line
The evidence does not support adding topical antimicrobials to oral levofloxacin for treating Pseudomonas and Staphylococcus infections between the toes. 1 Focus instead on ensuring adequate systemic antibiotic coverage with levofloxacin, proper wound care, and appropriate follow-up to confirm treatment response. 1