What is the recommended treatment for Otomycosis?

Treatment of Otomycosis

The recommended first-line treatment for otomycosis is topical therapy with irrigating solutions of boric acid, acetic acid, or azole creams, which are effective in eradicating fungal infections of the external ear canal. 1

Understanding Otomycosis

Otomycosis is a fungal infection of the external auditory canal, characterized by:

• Pruritus (itching)
• Pain
• Hypoacusis (hearing loss)
• Otic discharge
• Aural fullness

The most common causative organisms are:

• Aspergillus species (particularly A. niger and A. fumigatus) - accounting for 51-63% of cases
• Candida species - accounting for approximately 35% of cases
• Rarely, Mucor species

Treatment Algorithm

First-line Treatment:

1. Thorough cleaning of the ear canal

   • Atraumatic cleaning with suction under microscopic guidance is preferred
   • Physical removal of debris with suction or cotton applicator (dry mop)
   • Avoid cotton-tipped swabs which can cause trauma and worsen infection

2. Topical antifungal therapy:

   • For intact tympanic membrane:

     • Clotrimazole 1% solution/cream (88% resolution rate) 2
     • Boric acid or acetic acid solutions
     • Miconazole or other azole creams

   • For perforated tympanic membrane:

     • Oral antifungals may be appropriate: voriconazole, posaconazole, or itraconazole 1
     • Clotrimazole solution with patching is safe in managing otomycosis with tympanic membrane perforation 3

3. Duration of treatment: 7-14 days, even if symptoms improve earlier

For Refractory Cases:

• Reevaluate if no improvement after 72 hours
• Consider systemic antifungals (voriconazole, posaconazole, or itraconazole) for:
  • Perforated tympanic membrane
  • Immunocompromised patients
  • Extension into the middle ear or mastoid

Efficacy of Different Antifungals

• Clotrimazole 1% solution: 88.23% resolution rate 2
• Econazole nitrate 1% + triamcinolone acetonide 0.1% cream: 80.39% resolution rate 2
• Voriconazole: Highest sensitivity (93.48%) for mold isolates 4
• Nystatin: Highest sensitivity (88.24%) for yeast isolates 4

Prevention of Recurrence

• Keep ears dry
• Avoid excessive moisture in the ear canal
• Consider prophylactic acidifying solutions after water exposure
• Avoid swimming or water activities during treatment
• Use earplugs or cotton with petroleum jelly when showering

Important Considerations

• Topical therapy achieves higher drug concentration at the infection site with higher clinical cure rates (77-96%) compared to systemic antibiotics (30-67%)
• Patients with impaired mucosal or cutaneous immunity (hypogammaglobulinemia, diabetes mellitus, chronic eczema, HIV infection, corticosteroid use) are more susceptible to recurrent otomycosis
• If otomycosis is not successfully treated, fungal hyphae may extend into the mastoid sinus, creating chronic fungal mastoiditis
• The high virulence of fungal pathogens is due to their high enzymatic activity 4

Potential Pitfalls

• Avoid neomycin-containing products as first-line therapy as they can cause sensitization in 5-15% of patients with chronic otitis externa
• Discontinuing treatment prematurely can lead to incomplete treatment; complete the full course even if symptoms improve earlier
• Empirical use of antifungals without proper diagnosis should be discouraged 4
• Fluconazole shows 100% resistance against mold isolates and should be avoided 4
• Terbinafine shows 100% resistance against yeast isolates and should be avoided 4

The evidence supports that topical antifungal therapy, particularly with azoles like clotrimazole, is the most effective treatment for otomycosis, with thorough cleaning of the ear canal being an essential component of management.