Single application of clotrimazole cream in the management of fungal otitis externa

Background: Fungal otitis externa (FOE) is a common infection of the external ear canal. FOE is often associated with tympanic membrane perforation (TMP). This may be pre-existing or caused by the infection. The potential risk of ototoxicity from topical medication provides an additional treatment challenge for these patients. In this audit, a comparison is made of outcomes for patients with FOE managed with three different treatments. We compare two topical treatments licensed for use in Australia: flumetasone pivalate/clioquinol ear drops and triamcinolone acetonide/neomycin sulphate/gramicidin/nystatin ointment, with the off-label use of clotrimazole 1% cream. This is to determine if clotrimazole (the only treatment of the three without risk of ototoxicity) is as efficacious as the current licensed treatments. Methods: A review of patients diagnosed with FOE from a single Victorian specialist Ear, Nose and Throat (ENT) hospital Emergency Department (ED) was undertaken. Data from a 6-month period (March 2021–September 2021) were collected. Any patient who had presented to the ED, was subsequently confirmed on microscopy results to have FOE, and was reviewed 2 weeks post-treatment in ENT clinic was included. Successful treatment was defined as no further treatment requirement at the 2-week review. Results: Fifty-eight patients met the inclusion criteria. Ten of 16 patients (63%) were successfully treated with flumetasone pivalate/clioquinol eardrops. Twenty of 30 patients (67%) were successfully treated with triamcinolone acetonide/neomycin sulphate/gramicidin/nystatin ointment. Seven of 12 patients (58%) were successfully treated with clotrimazole 1% cream. There was no statistically significant difference between successful treatment rates between the topical treatments (Chi-square: 0.27, P=0.87). Conclusions: Clotrimazole appears to be as efficacious in the management of FOE as other topical antifungal agents. Although used off-label, it is not associated with ototoxicity. It should be considered an appropriate first-line treatment for patients with FOE, especially in the setting of TMP.