Fungal Infection of the Ear

Abstract

Fungal infections of the auditory canal and middle ear are usually left unnoticed and regarded as a harmless saprophytic growth. However, these infections may become clinically significant in immunocompromised patients or patients undergoing long-term antibiotic treatment. This is demonstrated by characteristic case reports and confirmed by light and electron microscopic findings. Moreover, studies on animals with experimentally induced fungal infections have furnished evidence for the risk of the infection’s spreading to the inner ear and causing serious damage to the organ of Corti; indirect damage to these structures by mycotoxins cannot be ruled out. To avoid complications of such severity of an allegedly harmless otomycosis we consider a quick and clinically easy to perform local treatment of high-risk patients as absolutely necessary. Such a treatment using bifonazole solution or cream was carried out on a number of patients and proved to be effective and free from side effects.

Fungal mastoiditis in an immunocompetent adult

“…The first hypothesis is the erosion of the bony wall by the fungus itself. Destruction of the bones including ossicles and bony walls of the mastoid cavity leading to semicircular canal fistula has been reported [13], and erosion of the ossicles was confirmed by an experimental study [3]. The second possibility is that the perilymph fistula was formed by the cooperation of fungal infection and cholesteatoma: the cholestetoma had caused the bony fistula, and then the massive granulations formed by the fungal infection detached from underneath the matrix covering the fistula, resulting in perilymph leakage.…”

“…In the case of chronic otitis media, fungi can spread to the tympanic cavity, but it usually remains a harmless, saprophytic growth, which does not call for intensive clinical intervention [3]. Khanna et al [8] reported that a pure fungal culture was obtained in 9.0% of chronic suppurative otitis media cases, all of which responded to topical antifungal treatment.…”

“…Labyrinthitis is considered to have been caused by the leakage of perilymph from the fistula of the lateral semicircular canal, because hearing and equilibrium recovered rapidly after occlusion of the fistula, which excludes total destruction of the inner ear structure by the fungi. However, the possibility of indirect damage by toxic substances produced by the fungus cannot be excluded [3]. Serologic analyses such as anti-fungal antibodies were not performed, since the patient was not immunodeficient or in immediate danger.…”

“…Since, in patients without systemic disease, the growth of fungi introduced from the external auditory canal through the perforated ear drum remain mostly saprophytic [3], the reason for the massive proliferation of fungi which caused granulations and inflammatory responses in this immunocompetent patient is unclear. However, an animal study clearly showed that the inoculated fungi proliferated in the middle ear and spread into the inner ear of a healthy individual [3]. Conservative treatment to prevent bacterial infection might have facilitated the fungal proliferation.…”

Fungal Mastoiditis in Immunocompromised Children

“…5 Even adenoid colonization followed by reflux otitis media has been proposed as a means of entry for fungal spores. 2 Fungi have been shown by Falser 6 to penetrate the oval and round window from the middle ear. In each of the cases presented, the host suffered from an immunocompromised state with likely colonization of the external ear preceding temporal bone involvement.…”