[Analysis of fungal infections of external auditory canal and its risk factors in patients with chronic otitis media]

Objective:The objective of this study is to analyze the detection rate, the pathogenic fungus distribution, risk factors and drug sensitivity of fungal infection of external auditory canal in patients diagnosed with chronic otitis media. Methods:The data of a total of 419 patients with chronic suppurative otitis media or middle ear cholesteatoma who were admitted from January 2019 to February 2023 were retrospectively analyzed. Results:A total of 419 patients were included, and 71 patients（16.9%） were positive for fungal culture. The disease mostly occurred in subjects aged 51-60 years old, and patients over 60 years old（47 cases, 66.2%）. From the fungal culture of external auditory canal secretions, 48 cases（11.4%） of Aspergillus and 14 cases（3.3%） of Candida were identified. The prevalence of fungal cultures in patients with chronic suppurative otitis media（20.8%） was significantly higher than that in patients with middle ear cholectestoma（4.9%）. The detection rate of Fungal was significantly increased after topical treatment with antibiotic ear drops（47.0% vs 13.6%）. Most of the isolated fungal strains are wild-type, and they are the sensitivity to voriconazole and fluconazole was the highest（97.2%）. For patients with positive fungal culture, iodoform gauze with triamcinolone acetonide and econazole cream was used to fill the external auditory canal during surgery. There was no significant difference in the tympanic membrane healing rate between patients with positive fungal culture and patients with negative fungal culture at 3 weeks after surgery（98.6% vs 97.7%）. Conclusion:Fungal infections of external auditory canal in patients with chronic otitis media tend to occur in older patients, which is more common in patients with chronic suppurative otitis media. Long-term topical treatment with antibiotic ear drops is an independent risk factor for fungal infection of external auditory canal in patients with chronic otitis media. The isolated fungal strains were highly sensitive to antifungal drugs. Therefore, it is advisable to refrain from employing topical antibiotic treatment for elderly patients with chronic suppurative otitis media/middle ear cholesteatoma, abuse of local antibiotic therapy should be avoided, and Fungal-related pathogenic examinations should be actively performed and anti-fungal drugs should be added if necessary.