Primary Otomycosis in the Indian Subcontinent: Predisposing Factors, Microbiology, and Classification

Abstract

Objective. To define otomycosis and determine the predisposing factors and microbiology in primary otomycosis.Study Design. Prospective study of two years and review of the literature.Setting. Academic Department of Otolaryngology in a coastal city in India.Patients. 150 immunocompetent individuals of whom 100 consecutive patients with a clinical diagnosis of otomycosis are considered as the study group and 50 consecutive patients with no otomycosis are considered as the control group.Results and Observations. Instillation of coconut oil (42%), use of topical antibiotic eardrops (20%), and compulsive cleaning of external ear with hard objects (32%) appeared to be the main predisposing factors in otomycosis. Aspergilli were the most common isolates (80%) followed byPenicillium(8%),Candida albicans(4%),Rhizopus(1%), andChrysosporium(1%), the last being reported for the first time in otomycosis. Among aspergilli,A. nigercomplex (38%) was the most common followed byA. fumigatuscomplex (27%) andA. flavuscomplex (15%). Bacterial isolates associated with fungi in otomycosis wereS. aureus,P. aeruginosa, andProteusspp. In 42% of healthy external ears fungi were isolated.Conclusion.Aspergillusspp. were the most common fungi isolated, followed byPenicillium. Otomycotic ears are often associated with bacterial isolates when compared to normal ears. Fungi are also present in a significant number of healthy external auditory canals and their profiles match those in cases of otomycosis. The use of terms “primary” and “secondary” otomycosis is important to standardize reporting.