Topical Antibiotic-Induced Otomycosis - a Systematic Review of Aetiology and Risk Factors

Otomycosis is a chronic or subacute fungal infection of external ear accounting to 5 to 20% of external ear infection worldwide. Literature has suggested multiple local and environmental host factors associated with otomycosis, but their strength of association is not well established. We did this review to analyse otomycosis with respect to it's various common predisposing factors. Human studies reporting ototopical antibiotics with or without steroids as predisposing factors for otomycosis, or pooled data together with other predisposing factors were included. MEDLINE, EMBASE, CINAHL, the ISRCTN register, and Cochrane databases were searched for the data extraction. Critical appraisal was done using the standardized Joanna Briggs Institute's (JBI) Appraisal checklist. Random effects were used to calculate pooled estimate prevalence with 95% Confidence Intervals (CIs). Age varied in different studies with a mean age variation from 7 to 43.19. Most of the studies were conducted in tropical and sub-tropical countries. Aspergillus was the most common species isolated. The use of ototopical antibiotics with or without steroid drops [47% (95% CI, 0.38 - 0.56)] were found to be the commonest predisposing factor for otomycosis, followed by the use of a variety of oils and wax solvents [38% (95% CI,0.26 - 0.51)] and trauma to the External Auditory Canal (EAC) as a result of compulsive cleaning or instrumentation[37% (95% CI, 0.21 - 0.54)]. We suggest the need for caution and vigilance from clinicians treating patients with ototopical drops for ear infections and use of other alternative treatment like 2% acetic acid for mild cases whenever feasible.