Mauldin Elizabeth A, Ness Timothy A, Goldschmidt Michael H
Department of Clinical Studies, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6051, USA.
Vet Dermatol. 2007 Oct;18(5):370-7. doi: 10.1111/j.1365-3164.2007.00614.x.
Proliferative and necrotizing feline otitis externa is a rare disorder of unknown aetiology. This condition was diagnosed by skin biopsy in three adult domestic shorthair cats (3-5 years old) and one kitten (6 months old). The affected cats had large tan to dark brown-black coalescing plaques covering the concave surface of the pinnae and external ear canals. Friable material from the plaques and a thick exudate occluded the ear canals. The cats had a secondary bacterial and/or yeast otitis. Prior to the histopathological diagnosis, all cats received numerous otic preparations as well as oral antibiotics and corticosteroids without resolution. Histologically, all cases had strikingly similar changes; acanthosis with pronounced hair follicle outer root sheath hyperplasia and neutrophilic luminal folliculitis, follicular keratosis and individually necrotic keratinocytes in the outer root sheath of hair follicles. One case was documented via skin biopsy to have persisted for 4 years. The adult cats were treated with topical 0.1% tacrolimus and all showed marked improvement although one cat was lost to follow up. The lesions completely resolved with topical tacrolimus alone in one cat and topical tacrolimus in addition to oral prednisolone in another cat.
增殖性和坏死性猫外耳炎是一种病因不明的罕见疾病。通过皮肤活检对3只成年家猫（3 - 5岁）和1只小猫（6个月大）诊断出这种疾病。患病猫的耳廓凹面和外耳道有大片棕褐色至深棕黑色融合性斑块。斑块处易碎物质和浓稠渗出物堵塞了耳道。这些猫继发了细菌性和/或酵母菌性耳炎。在组织病理学诊断之前，所有猫都接受了多种耳部制剂以及口服抗生素和皮质类固醇治疗，但均未见好转。组织学上，所有病例都有显著相似的变化；棘层肥厚伴明显的毛囊外根鞘增生和中性粒细胞性管腔内毛囊炎、毛囊角化病以及毛囊外根鞘中单个坏死的角质形成细胞。有一例经皮肤活检记录病程持续了4年。成年猫用0.1%他克莫司局部治疗，所有猫均有明显改善，不过有一只猫失访。一只猫仅用局部他克莫司治疗后病变完全消退，另一只猫除局部他克莫司外还加用了口服泼尼松龙后病变也完全消退。
