An animal model for external otitis

Emgård, Per; Hellström, Sten

doi:10.1007/bf02471273

Cited by 10 publications

(15 citation statements)

References 13 publications

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“…In all rats the lateral part of the right external auditory canal (EAC) was mechanically irritated through exposure to precisely 400 rotations of a plastic cone [3]. The diameter of the cut tip was 4 mm.…”

Section: Methodsmentioning

confidence: 99%

“…In all groups the EAC status was observed under methohexital anaesthesia once daily from days 1 to 7 except on day 6, and on days 10 and 20. The ear canal status was evaluated according to a scoring scale described earlier [3], including grading of colour, swelling and effusion. Colour was graded as 0 = normal, 1 = red and 2 = purple.…”

Section: Methodsmentioning

confidence: 99%

“…Some years ago an animal model [3] was introduced for studying external otitis. The inflammatory condition was evoked by mechanical stimulation of the external auditory canal.…”

Section: Introductionmentioning

confidence: 99%

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A topical steroid without an antibiotic cures external otitis efficiently: a study in an animal model

Emgård

Hellström

2001

European Archives of Oto-Rhino-Laryngology

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In an animal external otitis model, inflammatory reactions were evoked by mechanical stimulation of the rat ear canal skin. The rats were in four groups: group A treated with a group III steroid, betamethasone dipropionate; group B treated with hydrocortisone combined with oxytetracycline; group C treated with hydrocortisone with oxytetracycline and polymyxin B added; Group D, the controls, treated with saline. All rats were observed otomicroscopically daily during the first 7 days after treatment and then on days 10 and 20. A standardized scoring system was used to evaluate colour, swelling and effusion of the ear canal. Histological specimens were collected on days 3, 7, 10 and 20. The most rapid improvement in the ear canal status occurred in the animals treated with betamethasone dipropionate. The inflammatory reaction of the ear canal skin caused by mechanical stimulation was characterized by oedema of the stroma but few inflammatory cells were present. The surface of the epithelium towards the connective tissue layer was smooth in the group III-treated animals (group A) whereas other groups had irregularities of the basal membrane. From this study it is inferred that the group III steroid betamethasone dipropionate alone heals experimentally induced external otitis more rapidly than hydrocortisone with oxytetracycline, with or without polymyxin B. These findings should be considered in future clinical trials of external otitis.

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Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

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A topical steroid without an antibiotic cures external otitis efficiently: a study in an animal model

Emgård

Hellström

2001

European Archives of Oto-Rhino-Laryngology

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“…After 24 hours, a microscopic view confirmed the development of external otitis in both ears of the 40 rats. Reproduction of the bacteria in the samples taken from the infected ears was also observed [10] . Smear samples were taken for ear cultures at 24 hours after inoculation and on Days 4, 7, and 10 of the treatment.…”

Section: External Otitis Modelmentioning

confidence: 81%

“…Sections of 4 µm in thickness were cut, stained with hematoxylin and eosin, and evaluated in a random order by a pathologist blinded to the groups using an Olympus BX53 microscope ((ZA 3262, U-OCMC, 24 mm diameter, 10/100X); the modified Emgard et al [9,10] classification was used. The thicknesses of the stroma, keratin layer, and epithelium in the EAC were measured using an occulometer.…”

Section: Pathologic Evaluationmentioning

confidence: 99%

The Role of Topical Thymoquinone in the Treatment of Acute Otitis Externa; an Experimental Study in Rats

et al. 2018

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OBJECTIVE:The aim of this experimental study was to compare the dose-related effect of topical thymoquinone (TQ) with other topical agents used in the management of acute otitis externa (AOE) in a rat model. MATERIALS and METHODS:Forty-eight male Wistar albino rats were divided into six groups each with eight rats per group. Group I was the control group with no external otitis, whereas external otitis were created in the other five groups (study groups). Dexamethasone, 0.1% TQ, 0.4% TQ, ciprofloxacin, and 0.9% saline (NaCl) drops was applied once daily in Groups II-VI, respectively. The treatment was administered regularly for 10 days. Pathologic and microbiologic evaluation were performed. Pathologically, the thicknesses of the stroma and the epithelium in the external auditory canal (EAC) were measured using an occulometer. Edema in the stroma, density of inflammatory cells and blood vessels, presence of fibroblasts, and changes in collagen fibers in the EAC were evaluated in five different areas to obtain the area of highest concentration and classified into four grades (0=no change, 1=mild, 2=moderate, 3=severe). RESULTS:The higher concentration of TQ (0.4%) was more effective than dexamethasone and 0.1% TQ with respect to antibacterial and the anti-inflammatory properties. CONCLUSION:TQ, particularly at a concentration of 0.4%, may be considered for topical application alone in the treatment of AOE, without any requirement for a combined treatment.

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The use of trichloroacetic acid in the treatment of acute external otitis

Kantas

Balatsouras

Vafiadis

et al. 2006

Eur Arch Otorhinolaryngol

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The purpose of this study was to evaluate the effectiveness of 5% trichloroacetic acid (TCA) in the treatment of acute external otitis (AEO) in comparison with a standard clinical treatment. All patients who consecutively presented in our emergencies with AEO during the summer months of the previous year were included in the study. They were randomly divided into two groups: the study group included 117 patients treated with TCA and the control group included 98 patients treated with ear drops containing antibiotic and corticosteroid. Occasionally, an antibiotic was administered orally for 7 days, in severe cases of AEO. All patients were evaluated on days 1, 3, 5, 7 and 10, whereas another review appointment was given 20 days later. Outcome measures included evaluation of efficacy using a six-step infection score and tolerability by visual analogue scale. Additionally, adverse reactions, complications and recurrencies were recorded. Treatment was successful for all patients of the study group, whereas 8 failures were found in the control group. The infection score improved faster in the study group than in the control group, resulting in an earlier clinical cure (mean 4.1 and 8.6 days, respectively). Tolerability was significantly better in the study group, on all points of evaluation. Complications and adverse reactions were minimal on both groups. Our results show that TCA is a very effective and nontoxic agent for the treatment of AEO. Rapid pain relief and prevention of recurrencies are its main advantages.

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An animal model for external otitis

Cited by 10 publications

References 13 publications

A topical steroid without an antibiotic cures external otitis efficiently: a study in an animal model

A topical steroid without an antibiotic cures external otitis efficiently: a study in an animal model

The Role of Topical Thymoquinone in the Treatment of Acute Otitis Externa; an Experimental Study in Rats

The use of trichloroacetic acid in the treatment of acute external otitis

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