4.2 Study limitations
The findings of this study have to be seen in light of some limitations. The first is the variable length of treatment for each patient. Depending on the referral pathway, patients may have presented at a various stage of the clinical course of disease. In addition, each case received a different treatment regimen before referral. The diversity of interventions used in general practices has been previously reflected in data provided by the General Practice Research Database (GPRD) (4) and it has been demonstrated in our data (Chart 1). The second limitation concerns recording of possible side effects of fluticasone propionate. Although we did not systematically ask for side effects in our follow ups, none of our patients raised any concerns. The systemic bioavailability at 2400μg daily dose is estimated to be very low (0.06%). (11) Given the fact that fluticasone propionate was prescribed topically to the skin, not mucosa, the systemic bioavailability is likely to be lower than the figure cited above. Hence, it can be concluded that fluticasone propionate is likely to produce very small systemic exposures to steroids, and have a low potential for systemic side effects when administered topically to ears at 200μg daily dose. The last limitation is the restricted number of patients and those lost to follow up. It may be argued that the small sample size may over-estimate the magnitude of the association observed.
While recognising the limitations to our project, we believe that fluticasone propionate offers promise within a domain notoriously difficult to treat. There is no specific advice in guidelines regarding the choice of corticosteroids in chronic cases of otitis externa. (1,9) Also, the literature review reveals no previous study that has assessed the effectiveness of fluticasone propionate, or any other corticosteroid, for treatment of COE. In any future study, a larger sample size will be required, along with a recording of detailed clinical features including any concurrent disease modalities, side effects and social factors. Considering the size of the problem (7,8), we believe the clinical practice in the field of otolaryngology will benefit from a prospective study that allows randomized head-to-head comparison for efficacy and safety of fluticasone propionate, in chronic cases of otitis externa.

Conclusion

Chronic otitis externa is often a recalcitrant problem and a challenge for the attending doctor. In the absence of guideline recommendations regarding the choice of corticosteroids for chronic otitis externa, we present a case-series demonstrating the potential benefit of fluticasone propionate. All patients (20/20) who returned to the follow up showed resolution of symptoms, having previously failed with a multitude of conventional management options. We did have some limitations which we hope could be analysed further with a more robustly designed study, however the use of Flixonase® is an exciting and potentially important tool in the arsenal of the otolaryngologist.