Challenges in Otitis

Abstract

Amanda Burrows (Australia) opened the meeting and commented that she was delighted to have so many experts in otitis present for this workshop. She began with a short summary, introducing the different speakers and their topics for the afternoon. Developing an objective clinical score for canine otitis externa (T. Nuttall) Tim Nuttall (UK) outlined a pilot study for the development of a scoring system for the clinical signs of otitis. He explained that a consistent clinical scoring scheme would enable comparison between different studies conducted by different investigators. Two clinical presentations of otitis were evaluated: an erythro-ceruminous form and a suppurative form of otitis externa. Scoring systems that had already been utilized in varying studies or in clinical trials were used and compared: for each ear and for the horizontal and vertical ear canal. The parameters of erythema, oedema, swelling, erosion/ulceration, exu-dation, pain, odour, tympanic membrane condition, secondary infections and treatment outcome were evaluated. The study compared different scoring systems including numeric scoring schemes, in which each parameter was assigned a score of 0 to 2, 0 to 3 or 0 to 5; a visual analog scale, an owner pruritus score and an owner pain score. Two centres were involved (located in France and the UK) and 40 ears from 20 healthy dogs and 90 ears from 50 dogs with otitis were analysed. The 0 to 3 scoring system was the most reliable with regard to the parameters erythema, oedema/swelling, erosion/ulceration and exudation. Other parameters, including pain and pruritus, did not correlate with the clinical scores. A maximum total score of 12 for each ear could be achieved using this system. A score of >4 differentiated affected ears from healthy ears (70% sensitivity and 100% specificity) and a score of £3 was 99% sensitive for clinical resolution. Tim Nuttall suggested that the presence, but not the number of neutrophils and microorganisms was found to be additionally useful. He proposed that the next step with the development of this otitis externa scoring system would be the assessment of intra-and inter-observer reliability.