Is clarithromycin (a macrolide antibiotic) effective for treating perichondritis?

Clarithromycin for Perichondritis

Clarithromycin is NOT recommended for perichondritis because it lacks adequate coverage against Pseudomonas aeruginosa, which is the predominant pathogen in this infection, particularly in abscess-forming cases (58-69% of isolates). 1, 2

Bacterial Etiology Determines Antibiotic Choice

The microbiology of perichondritis varies significantly based on clinical presentation:

• Abscess-forming perichondritis: Pseudomonas aeruginosa predominates (58-69% of cases) 1, 2
• Non-abscess perichondritis: Staphylococcus aureus is the primary pathogen (49% of cases, with 82% showing heavy or moderate growth) 1
• In over half of perichondritis cases, the etiology cannot be determined initially 2

Why Clarithromycin Fails

Clarithromycin, as a macrolide antibiotic, has no clinically reliable activity against Pseudomonas aeruginosa. While macrolides demonstrate excellent activity against many Gram-positive bacteria and some Gram-negative organisms 3, they are not considered effective anti-pseudomonal agents. This is a critical gap since P. aeruginosa is associated with more advanced clinical presentation and longer hospitalization in perichondritis 2.

Recommended Antibiotic Approach

For initial empirical therapy in non-abscess perichondritis:

• Intravenous antibiotics covering Staphylococcus aureus are sufficient in the majority of cases 1
• No significant differences were found in clinical progress, duration of hospitalization, or relapse rates between S. aureus coverage versus P. aeruginosa coverage in non-abscess cases (p = 0.65) 1

When to expand coverage to include P. aeruginosa:

• If clinical response is disappointing after 48-72 hours 1
• If cultures grow P. aeruginosa 1
• In abscess-forming perichondritis, where P. aeruginosa predominates 1, 2

Effective Anti-Pseudomonal Options

Fluoroquinolones are the preferred oral agents for P. aeruginosa perichondritis:

• Ciprofloxacin (oral): Successfully treats P. aeruginosa auricular perichondritis as outpatient therapy, avoiding prolonged hospitalization and IV antibiotics 4
• Norfloxacin (oral): Demonstrated efficacy in treating auricular perichondritis with antipseudomonal activity 5

These fluoroquinolones provide the critical anti-pseudomonal coverage that clarithromycin cannot deliver.

Clinical Pitfalls to Avoid

• Do not use clarithromycin monotherapy for perichondritis, as it will fail against P. aeruginosa, the most serious pathogen in this infection 1, 2
• Do not delay appropriate anti-pseudomonal coverage in patients with abscess formation, as P. aeruginosa is found in 58-69% of these cases 1, 2
• Prior treatment before hospitalization (occurring in 41% of patients) averaged only 2.5 days, suggesting early treatment failure with inadequate antibiotic selection 2
• 7% of patients required surgical intervention, emphasizing the importance of appropriate initial antibiotic selection 2

Alternative Approach for Severe Cases

For perichondritis with abscess or severe infection, consider local irrigation with streptomycin solution combined with streptomycin, hyaluronidase, and triamcinolone to avoid surgical drainage while providing direct anti-pseudomonal activity 6. This approach avoids the conventional surgical procedure and may prevent "cauliflower ear" deformity 6.