Griffin Craig
Animal Dermatology Clinic, San Diego, California, USA.
Compend Contin Educ Vet. 2009 Nov;31(11):504-12.
Chronic otitis externa is a difficult, frustrating problem. Four etiologic components must be considered: primary and secondary causes and perpetuating and predisposing factors.1 Usually, these cases are complex and involve more than one component. Perpetuating factors are changes in the anatomy and physiology of the ear that occur in response to inflammation in the ear canal and the perpetuating factors already present. They are self-perpetuating, are not disease specific, and include failure of self-cleaning mechanisms and proliferative changes that create folds and stenosis of the lumen of the ear canal. Elimination of perpetuating factors often requires aggressive cleaning of the ear and long-term therapy. It is important to avoid damaging key structures while aggressively cleaning the ear. Therefore, to adequately diagnose and manage perpetuating factors, veterinarians must recognize normal ear anatomy and physiology.
慢性外耳炎是一个棘手且令人沮丧的问题。必须考虑四个病因要素：原发性和继发性病因以及持续性和易患因素。通常，这些病例情况复杂，涉及不止一个要素。持续性因素是耳部解剖结构和生理机能的变化，这些变化是外耳道炎症以及已存在的持续性因素所引发的反应。它们会自我延续，并非特定于某种疾病，包括自我清洁机制失效以及导致耳道管腔出现褶皱和狭窄的增生性变化。消除持续性因素往往需要积极清洁耳部并进行长期治疗。在积极清洁耳部时避免损伤关键结构很重要。因此，为了充分诊断和处理持续性因素，兽医必须了解正常的耳部解剖结构和生理机能。
