Does a 13-year-old boy with otitis externa still benefit from using Kenacomb (triamcinolone) drops after a swab culture shows only growth of skin flora, indicating no infection?

Management of Otitis Externa with Normal Skin Flora Culture

Kenacomb drops should be discontinued as they are not necessary when the ear swab culture shows only normal skin flora with no pathogenic organisms. 1

Understanding the Situation

This 13-year-old boy has been treated for otitis externa with ear cleaning and Kenacomb drops (containing triamcinolone acetonide, neomycin, gramicidin, and nystatin). The swab culture from the right ear shows only growth of normal skin flora, indicating no pathogenic infection is present.

Treatment Recommendations

Primary Recommendation

• Discontinue Kenacomb drops since:
  • The American Academy of Otolaryngology-Head and Neck Surgery guidelines emphasize that topical antimicrobials are only necessary when infection is present 1
  • The culture showing only skin flora indicates no pathogenic infection requiring antimicrobial treatment
  • Unnecessary use of antimicrobials can lead to altered flora and potential development of resistance 1

Alternative Management

• Focus on non-antimicrobial measures:
  • Continue gentle cleaning of the ear canal to remove debris that may cause irritation 1
  • Use analgesics as needed for any remaining discomfort (acetaminophen or NSAIDs) 2
  • Avoid inserting anything into the ear canal, including cotton-tipped swabs 1
  • Maintain ear dryness by covering the ear canal during showering 1

Rationale for Recommendation

1. Evidence against continued antimicrobial use:

   • The 2014 clinical practice guideline for acute otitis externa clearly states that antimicrobial therapy should be targeted to actual infections 1
   • When only normal skin flora is present, there is no indication for continued antimicrobial therapy

2. Risks of continued unnecessary treatment:

   • Potential for contact sensitivity, especially with neomycin (present in Kenacomb) which has a 13-30% prevalence of contact sensitivity in patients with chronic otitis externa 1
   • Risk of developing bacterial resistance with unnecessary antimicrobial use 1
   • Possible alteration of normal ear canal flora, which could predispose to fungal overgrowth 1

Special Considerations

• Monitor for resolution: If symptoms persist despite discontinuation of antimicrobial drops, reassessment is warranted 1
• Prevention of recurrence: Advise the patient to keep the ear dry and avoid inserting objects into the ear canal 1
• Follow-up: Consider follow-up only if symptoms persist or worsen after discontinuation of drops 1

Common Pitfalls to Avoid

1. Overtreatment: Continuing antimicrobial therapy when no pathogenic organisms are present can lead to unnecessary side effects and resistance 1

2. Misinterpreting normal flora: Normal skin flora on culture does not indicate treatment failure but rather suggests that either:

   • The initial infection has resolved
   • The condition may have been primarily inflammatory rather than infectious

3. Neglecting ear cleaning: Even after discontinuing drops, proper ear hygiene remains important to prevent recurrence 1

4. Ignoring persistent symptoms: If symptoms persist after discontinuing antimicrobial therapy, reconsider the diagnosis or evaluate for other causes of external ear inflammation 1