What is the recommended treatment for fungal otitis externa?

Treatment of Fungal Otitis Externa

The recommended first-line treatment for fungal otitis externa (otomycosis) is thorough mechanical cleansing of the external auditory canal followed by topical antifungal therapy or boric acid. 1, 2

Diagnosis and Etiology

• Fungal otitis externa (otomycosis) is most commonly caused by Aspergillus species and Candida species 2, 3
• Common symptoms include pruritus, pain, hypoacusis, and otic discharge 2
• Fungal infections often develop after treatment with topical or systemic antibiotics that alter the normal flora 1

Treatment Algorithm

First-Line Treatment

• Thorough mechanical cleansing and debridement of the external auditory canal is essential before administering medication 1, 2
• Aural toilet, including gentle suction, dry mopping, or irrigation to remove obstructing debris ensures medication reaches infected tissues 1
• After cleansing, apply topical antifungals or boric acid 4, 1

Topical Antifungal Options

• For intact tympanic membranes: boric acid, acetic acid solutions, or azole creams (clotrimazole, miconazole, bifonazole) 2, 5
• For perforated tympanic membranes or tympanostomy tubes: non-ototoxic preparations such as clotrimazole and miconazole must be used 2
• Treatment typically continues for 2-3 weeks, with most patients showing clinical resolution within 2 weeks 2

Special Considerations

Immunocompromised Patients

• Patients with diabetes, immunocompromised states, or history of radiotherapy require special monitoring as they are more susceptible to otomycosis and necrotizing otitis externa 1
• More aggressive treatment and closer follow-up are warranted in these populations 1
• For invasive Aspergillus otitis of the ear, a prolonged course of systemic voriconazole is usually combined with surgical intervention 4, 2

Treatment Failure

• If no improvement occurs within 48-72 hours, consider treatment failure, allergic contact dermatitis, or misdiagnosis 1
• Reasons for treatment failure may include inadequate drug delivery due to canal obstruction, poor adherence to therapy, incorrect diagnosis, or contact dermatitis from topical agents 6
• Follow-up is recommended if symptoms persist beyond 2 weeks after initiation of therapy 1

Common Pitfalls to Avoid

• Failure to remove debris before administering drops, which prevents medication from reaching infected areas 1
• Using topical antibiotics alone may promote fungal overgrowth 2
• Using ototoxic preparations when tympanic membrane integrity is compromised 1, 2
• Missing fungal infections, especially in patients with diabetes or those who fail to respond to antibacterial therapy 1, 6
• Inadequate pain management, which can significantly impact patient satisfaction 1

Prevention

• Address underlying predisposing factors and maintain good ear hygiene to help prevent recurrence 2
• Acidification with a topical solution of 2% acetic acid combined with hydrocortisone can be used as prophylaxis after exposure to moisture 7
• Drying the ears with a hair dryer and avoiding manipulation of the external auditory canal may help prevent recurrence 7