To evaluate effects on external ear epithelium and secretory glands of topical and intracutaneous botulinum toxin application in rat model

Purpose: The aim of this study is to investigate the use of botulinum toxin about the possible histopathological effects on the rat external ear path epithelium and secretory glands. It is targeted with this study, the effect of botulinum toxin on the external ear path and contribute literature about whether applied is reliable. Materials and Methods: This experimental study was conducted on 48 rats, in Baskent University Faculty of Medicine Experimental Animal Research Laboratory. The rats were divided into 2 main groups according to the application forms. The two main groups were divided into three subgroups according to follow-up periods. Botox was applied to the right external auditory canal of all animals. No treatment was applied to the left ears and the control group was identified. Botox applied group I topically, group II Intracutaneous injection. Group Ia and IIa were sacrificed on day 10, and groups Ib and IIb were sacrificed on day 30. Group Ic and IIc received a second dose of botox on the 30th day and these groups were sacrificed on the 10th day of the second application. At the end of the application and follow-up period, the rats were decapitated and the external ear canal was disrupted and the pathology was delivered. Results: Inflammation was found in all groups, but no statistically significant difference was observed between the groups (p> 0,05). There was no change in the amount of secretion in all groups. Calcification was seen only in group II. It was statistically higher than control group and group I (p=0,0001). Apoptosis was observed in all groups. ApopTag scores were statistically higher in groups I and II compared to control group. There was no statistically significant difference between group I subgroup ApopTag scores (p>0.05). When the ApopTag scores of group II subgroups are compared among themselves; the sebaceous gland score (p=0,003) according to IIa in IIb, epithelium (p=0,021) and sebaceous gland (p=0,01) scores were statistically significant higher according to IIa in Conclusions: This study has shown that botulinum toxin causes inflammation, calcification and apoptosis in the external ear path epithelium and glandular secretions of rats and does not alter the amount of secretion. However, increasing the administered dose of botulinum toxin, application in repeated doses and prolonging post-administration period benefit may give more positive results. For this reason it is thought that this work should be supported by further experimental and clinical studies. Keywords: Botox, External Ear, Intracutaneous, Rat, Serumen, Topical