4.1 Synopsis of key finding
Here, we have investigated the outcome of using fluticasone propionate topically in 25 case of COE. As presented in the section above, all cases who returned to the follow up reported significant improvement and showed resolution of symptoms. When applied topically, fluticasone propionate, a potent corticosteroid, relieves pruritic and inflammatory symptoms through binding and activation of glucocorticoid receptors. (12) It should be noted that more than 70% of our patients used treatment modalities which contained some corticosteroids, with Sofradex® and Gentisone HC ear drops being the most common ones. A comparison between the steroid concentration of all three drops, shows that daily dosage of fluticasone propionate contains significantly higher concentration of corticosteroids, compare to the other two drops. Sofradex® ear drop (0.5% w/v of Framycetin, Sulphate 0.005% w/v of Gramicidin and 0.050% w/v of Dexamethasone) contains 50 micrograms of corticosteroid per 100 ml (13), and it delivers 0.3 micrograms of corticosteroid to the external ear canal when applied in its maximum daily dose. Gentisone HC ear drops (Gentamicin 0.3% w/v and Hydrocortisone acetate 1% w/v Ear Drops) contains 1000 micrograms of corticosteroid per 100 ml (14); which is equivalent to 8 micrograms of steroid per day when it is applied in its maximum dose. Given that our cases received 200 micrograms of fluticasone propionate daily, the significant difference in the amount of highly potent corticosteroid delivered to the external ear canal could explain the successful response observed in cure rate of resistant cases with a course of Flixonase® alone.