Misdiagnosis of a fungus ball in the middle ear as chronic suppurative otitis media.

Background: Middle ear infections caused by fungi are commonly identified through laboratory tests like fungal smears, culture, and DNA detection. There are two types of ear infections caused by fungi: middle ear fungal infections and fungal otitis media. Both fungal otitis media and fungus balls in the middle ear are increasingly rare.

Case description: A middle-aged immunocompetent woman suffered from long-term recurrent pus formation in the middle ear and associated hearing loss. Physical examination revealed a perforation in the pars tensa of the tympanic membrane; a pure tone audiometry test revealed mild conductive hearing loss. The woman had previously self-medicated with oral antibiotics and/or ear drops multiple times in the past. She did not have a history of diabetes mellitus. She was diagnosed with chronic suppurative otitis media and surgical treatment (tympanoplasty) was advised. Otoscopy-guided tympanoplasty revealed a fungal mass with a cheese-like consistency filling the entire mesotympanum, and important structures such as the ossicular chain and the facial nerve were unharmed. Lesions were meticulously excised from the tympanic cavity of the affected ear. The patient no longer experienced pus formation in the middle ear and loss of hearing was restored after the surgery. After tympanoplasty, the patient did not experience any symptom recurrence during the 10-month follow-up period.

Conclusions: If a patient has good immune function and no history of diabetes mellitus, despite repeated antibiotic use resulting in a diagnosis of chronic otitis media, doctors should consider the possibility of a fungal infection in the middle ear.