fungal otitis externa

Last edited 04/2021 and last reviewed 05/2021

Otomycosis

  • a common condition encountered and its prevalence is about 10% among patients who presented with signs and symptoms of otitis externa (1,2,3)


  • pathologic entity, with candida and aspergillus the most common fungal species
    • not clear that the fungi are the true infective agents or mere colonization species as a result of compromised local host immunity secondary to bacterial infection

  • various predisposing factors include a humid climate, presence of cerumen, instrumentation of the ear, increased use of topical antibiotics / steroid preparations, immunocompromised host, patients who have undergone open cavity mastoidectomy and those who wear hearing aids with occlusive ear mold
    • infection is usually unilateral and characterized by inflammatory pruritis, scaling and otalgia (4)

  • investigation
    • swabs from infected ears should be examined for both bacteriology and mycology
    • difficult to cultivate fungi such as Malassezia species can be revealed by use of 10% KOH (Potassium Hydroxide) mount and inoculated on to SDA (Sabouraud's Dextrose Agar) for culture

  • treatment recommendations have included local debridement, antifungal agents (topical or systemic depending on severity and other factors) and discontinuation of topical antibiotics (3)
    • sometimes otomycosis presents as a challenging disease for its long term treatment and follow up, yet its recurrence rate remains high
    • if a otomycosis is suspected then
      • prescribe a topical antifungal preparation. For mild-to-moderate and uncomplicated fungal infections, consider one of the following options (4):
        • Clotrimazole 1% solution.
        • Acetic acid 2% spray (unlicensed use).
        • Clioquinol and a corticosteroid (for example Locorten-Vioform®)
      • if there is inadequate response then seek specialist advice (4)

Reference:

Related pages:

clinical features

management

prognosis

otitis externa