What are the clinical presentations of fungal otitis externa (infection of the outer ear canal)?

From the Guidelines

Fungal otitis externa typically presents with pruritus, pain, hypoacusis, and otic discharge.

Clinical Presentations

• The infection usually involves the external auditory canal and may extend to the middle ear if the tympanic membrane is perforated.
• Aspergillus species, particularly A. niger and A. fumigatus, are commonly associated with this condition 1.
• Patients with impaired mucosal or cutaneous immunity, such as those with hypogammaglobulinemia, diabetes mellitus, chronic eczema, or HIV infection, are more susceptible to fungal otitis externa 1.

Symptoms and Complications

• Symptoms may include pruritus, pain, hypoacusis, and otic discharge 1.
• If left untreated, the infection may lead to chronic fungal mastoiditis 1.
• Erosion and disruption of the epidermis may serve as a portal of entry for superinfection by opportunistic bacterial infections in immunocompromised patients 1.

Treatment

• Topical therapy using irrigations with acetic acid or boric acid may be beneficial 1.
• Topical antifungal creams and ointments may be useful, but their effectiveness is not well studied 1.
• Orally administered antifungals, such as itraconazole, voriconazole, or posaconazole, may be effective, but there are no published studies to support their use 1.

From the Research

Clinical Presentations of Fungal Otitis Externa

The clinical presentations of fungal otitis externa can vary, but common symptoms and findings include:

• Itching in the external auditory canal 2
• Painful infection in the ear canal 3
• Fungal debris in the external auditory canal 2
• Trauma to the external auditory canal as a predisposing factor 2
• Infection caused by various fungal pathogens, including Aspergillus and Candida species 4, 3, 2, 5

Fungal Pathogens Involved

The most common fungal pathogens involved in otitis externa are:

• Aspergillus species, with Aspergillus niger being the most common cause of otomycosis 2
• Candida species, including Candida auris and Candida albicans 3, 5
• Other opportunistic fungal infections, which can be especially important in certain populations, such as patients with diabetes, patients recently treated with antibiotics, and immunosuppressed patients 4

Patient Populations at Risk

Certain patient populations are at a higher risk of developing fungal otitis externa, including:

• Patients with diabetes 4
• Patients recently treated with antibiotics 4
• Immunocompromised patients 4
• Manual workers and students, who had the highest frequency of otomycosis based on occupational incidence 2
• Males aged 21-40 years, who were more commonly affected by otomycosis 2