Abstract
External otitis was produced in 12 Sprague-Dawley rats by mechanical stimulation through a plastic micropipette inserted into the right external auditory canal (EAC). The EAC was later evaluated regarding the color of the skin, swelling and the presence of fluid. Within 1 day all rats developed an external otitis that was characterized by a red, swollen ear canal containing an opalescent fluid. The tympanic membrane and middle ear cavity appeared to be normal. No healed EACs were seen within the initial 10 days of follow-up and 4 of 6 rats still exhibited external otitis at day 21. Light microscopy of biopsy specimens revealed pronounced edema of the dermis of the ear canal. Mast cells were more numerous in the early phase of the otitis present, although very few inflammatory cells were found in tissues despite the marked inflammatory reaction produced. Findings show that this animal model for external otitis can be used to investigate pathogenesis as well as to test various treatment strategies.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
References
Albiin N, Hellström S, Salén B, Stenfors L-E, Söderberg O (1983) The anatomy of the Eustachian tube in the rat: a macroand microscopical study. Anat Rec 207:513–521
Alm P-E, Bloom GD, Hellström S, Stenfors L-E, Widemar L (1982) Mast cells in the pars flaccida of the tympanic membrane. A quantitative morphological and biochemical study in the rat. Experentia 39:287–289
Alm P-E, Bloom GD, Hellström S, Stenfors L-E, Widemar L (1983) Middle ear effusion caused by mechanical stimulation of the external auditory canal. An experimental study in the rat. Acta Otolaryngol (Stockh) 96:91–98
Barr GD, Al-Khabori M (1991) A randomzied prospective comparison of two methods of administering topical treatment in otitis externa. Clin Otolaryngol 16:547–548
Reference deleted
Goldie P, Hellström S, Johansson U (1990) Vascular events in experimental otitis media models: a comparative study. ORL 52:104–112
Hellström S, Goldie P (1991) Mechanisms of otitis media development. Neurogenic inflammation involved? Otolaryngol Clin North Am 24:829–834
Hellström S, Salén B, Stenfors L-E (1982) Anatomy of the rat middle ear. Acta Anat 112:346–352
Hellström S, Tengblad A, Johansson C, Hedlund U, Axelsson E (1990) An improved technique for hyaluronan histochemistry using microwave irradiation. Histochem 22:677–682
Hermansson A, Emgård P, Prellner K, Hellström S (1988) A rat model for pneumococcal otitis media. Am J Otolaryngol 9:97–101
Laurent TC, Fraser JRE (1992) Hyaluronan. FASEB J 6:2397–2402
Laurent C, Hellström S, Engström-Laurent A, Wells AF, Bergh A (1995) Localization and quantity of hyaluronan in urogenital organs of male and female rats. Cell Tissue Res 279:241–248
Wadsten C-J, Bertilsson CA, Sieradzki H, Edström S (1985) A randomized clinical trial of two topical preparations (Framycitin/Gramicidin and Oxytetracycline/Hydrocortisone with Polymyxin B) in the treatment of external otitis. Arch Otorhinolaryngol 242:135–139
Weibel ER (1979) Stereological methods. Practical methods for myological morphometry, vol 1. Academic Press, London, pp 101–161
Widemar L, Hellström S, Stenfors L-E, Blom GD (1986) An overlooked site of tissue mast cells — the human tympanic membrane. Implications for middle ear affections. Acta Otolaryngol (Stockh) 102:391–395
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Emgård, P., Hellström, S. An animal model for external otitis. Eur Arch Otorhinolaryngol 254, 115–119 (1997). https://doi.org/10.1007/BF02471273
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF02471273