严重疼痛表现的犬耳软骨炎的诊断和临床管理方案

王帆

Diagnosis and clinical management of auricular chondritis in a dog presenting for evaluation of severe pain

严重疼痛表现的犬耳软骨炎的诊断和临床管理方案

James O. Noxon*, Darren J. Berger* , Mark A. Ackermann†, Jennifer R. Petersen* and Jodi D. Smith‡

翻译：王帆

摘要

背景 – 目前尚不清楚犬耳软骨炎的病因以及合理治疗方法。本报告描述了耳软骨炎患犬的独特表现和有效治疗方案。

Background – The aetiology and appropriate treatment for auricular chondritis in the dog are currently unclear. This report describes a unique presentation and successful treatment of a dog with auricular chondritis.

临床总结 – 一只12岁的已绝育雌性拉布拉多猎犬，因严重疼痛就诊，认为是神经源性。疼痛位于右侧耳廓，打孔采样并评价了两个皮肤活检样本，显示淋巴浆细胞性至脓性肉芽肿性炎症，累及耳软骨，无感染因素。全身口服泼尼松，临床症状在开始治疗后4周内缓解。停止治疗后6个月内犬持续无临床症状表现，之后因其他原因被安乐死。

Clinical summary – A 12-year-old, female spayed, Labrador retriever dog was presented for severe pain thought to be neurological in origin. The pain was located to the right pinna and two punch biopsies were acquired and evaluated, revealing lymphoplasmacytic to pyogranulomatous inflammation involving the auricular cartilage with no infectious agents. Treatment with systemic oral prednisone resulted in resolution of clinical signs within four weeks of initiation of treatment. The dog remained free of clinical signs for six months following discontinuation of treatment before being euthanized for an unrelated reason.

结论 – 需要进一步评价犬耳软骨炎，但疼痛可能是一个明显的表现；全身泼尼松单药治疗可快速和完全消退临床症状。

Conclusions – Further evaluation of canine auricular chondritis is needed, yet pain may be a prominent finding; monotherapy with systemic prednisone may provide quick and complete resolution of clinical sysmptoms.

Case report

病例报告

Auricular chondritis is a rare condition reported in animal species. The aetiology and treatments for this condition in dogs are not clear owing to a lack of published reports in the veterinary literature outside abstracted works.

在动物身上耳软骨炎是一种罕见的疾病情况。由于缺乏在兽医文献中发表的报告，犬这种疾病的病因学和治疗尚不清楚。

A 12-year-old, female spayed, Labrador retriever dog was referred for evaluation of severe pain over the right side of the head and neck, suspected to be neurological in origin. Onset of progressive generalized pain and discomfort affecting the cervical and cranial regions were noted two months previously. No history of trauma was reported; clinical signs of right-sided Horner’s syndrome were observed several months before presentation. Treatment before presentation included use of tramadol. The patient had no history of cutaneous disease and a complete blood cell count, serum chemistries, urinalysis and total thyroxine assessment performed before presentation were within reference intervals.

一只12岁，与绝育雌性拉布拉多猎犬，由于头部和颈部右侧严重疼痛，怀疑是神经源性而被转诊。在两个月前出现，渐进性全身性疼痛和颈部和头部不适。无外伤病史，在症状出现前几个月，观察到右侧霍纳氏综合征的临床症状。症状出现前治疗包括使用曲马多。患者无皮肤疾病史，在发病前进行的全血细胞计数、血清化学、尿检和总甲状腺素水平均在参考范围内。

Physical examination revealed hind limb weakness and muscle atrophy in both rear legs with elicitation of pain on manipulation of the lumbosacral spine and coxofemoral joints. Miosis, enopthalmia and ptosis of the right eye were present and consistent with prior reported clinical signs. A mild right head tilt with lower carriage of the right pinna were appreciated. The right pinna (Figure 1) was moderately erythematous, swollen and extremely sensitive, with the patient reacting aggressively upon manipulation, precluding thorough and comprehensive neurological and otological examinations.

体格检查显示后肢无力和双下肢肌肉萎缩，并在初诊腰荐椎和胯髋关节时引起疼痛。右眼畸形、眼内丘脑和上睑下垂的出现与先前报告的临床症状一致。头轻微向右侧倾斜，右耳廓向下倾斜。右耳廓(图1)有中度红斑、肿胀和极度敏感，操作时患犬反应强烈，无法进行彻底、全面的神经和耳部检查。

Differential diagnoses included otitis media/interna, trauma, neuritis/neuropathy, meningitis, intervertebral disk disease, arthritis, vasculitis, primary pinnal disease and neoplasia. General anaesthesia was induced in order to perform otoscopic examination, computerized tomography (CT) and pinnal biopsy. Otoscopic examination of both external ears showed canals of normal appearance with intact translucent tympanic membranes. The CT scan of the patient’s skull and proximal cervical region revealed pronounced thickening of the right pinna (Figure 2), no other musculoskeletal or soft tissue abnormalities, no evidence of nerve entrapment, no brain or proximal cervical spinal cord lesions, and clear, air-filled bullae. Two biopsy samples from the right concave scapha were acquired using a 6 mm biopsy punch and closed with simple interrupted sutures. Oral tramadol (Mylan Pharmaceuticals Inc.; Morgantown, WV, USA) was prescribed at 3 mg/kg three times daily for pain management.

鉴别诊断包括中耳炎/中耳炎、外伤、神经炎/神经疾病、脑膜炎、椎间盘疾病、关节炎、血管炎、原发性耳廓疾病和肿瘤。全身麻醉后进行耳镜检查、计算机断层扫描(CT)及耳廓活检采样。耳镜检查显示耳道外观正常，鼓膜完整透明。患病动物头部和颈椎前端CT扫描显示右侧耳廓明显增厚(图2)，无其他肌肉骨骼或软组织异常，无神经压迫，无脑或颈椎脊髓前端病变，鼓室大疱干净且充满气体的。使用6毫米皮肤活检打孔器从右侧耳廓凹面采集两个活检样本，并进行简单结节缝合。口服曲马多每天3次，每次3毫克/公斤，用于疼痛管理。

Histopathological findings revealed marked lymphoplasmacytic and pyogranulomatous inflammation with multinucleated histiocytic cells adjacent to and around necrotic cartilage (Figure 3). Additional histochemical staining (Gram stain, Gomori’s methenamine stain, Acidfast stain) was negative for infectious agents. These findings were consistent with auricular chondritis and the patient was prescribed oral prednisone (Cadista Pharmaceuticals, Inc.; Salisbury, MD, USA) at a dose of 2.2 mg/ kg once daily. Follow-up at two weeks revealed that the dog was in significantly less pain and the head tilt was no longer evident. After an additional two weeks, pinnal pain and swelling were resolved completely. A neurological consultation revealed persistent right-sided miosis, enopthalmia and ptosis with no other neurological deficits, and the patient was diagnosed with idiopathic Horner’s syndrome. Prednisone dosing was reduced to alternate days and slowly tapered until being discontinued after 14 weeks of treatment. The dog remained asymptomatic for an additional six months until euthanasia at the owners’ primary veterinarian’s office for unrelated problems.

组织病理学检查显示坏死软骨附近和周围明显出现伴有多核组织细胞的淋巴浆细胞性和脓性肉芽肿性炎症反应(图3)。对感染性病原另做组织化学染色(革兰氏染色、六胺银染色、耐酸染色)呈阴性。这些结果与耳软骨炎一致，病患进行口服泼尼松治疗，每日一次，每次剂量为2.2 mg/ kg。两周后复诊，患犬疼痛明显减轻，头部倾斜不再明显。再过两周，耳廓疼痛和肿胀完全消失。进行神经学会诊显示持续性右侧瞳孔缩小、眼部炎症和眼睑下垂，没有其他神经功能损伤，病患被诊断为特发性霍纳氏综合征。泼尼松的剂量减少为隔天一次，并逐渐减量，直到14周治疗后停药。在接下来的六个月里，这只犬一直没有症状，直到因其他问题在主人的首诊动物医院接受安乐死。

Reports of canine auricular chondritis are limited, with papules, nodules, erythema and swelling affecting the pinna being described previously. Pain has not been a consistent finding in canine cases, yet is frequently observed in cats. Benign neglect and surgical excision have been suggested as treatment options for dogs, with systemic glucocorticoids being considered ineffective in cats.

有关犬耳软骨炎的报告是有限的，以前的患病耳廓病变描述有丘疹、结节、红斑和肿胀。在犬病例中并不总表现疼痛，但在猫中经常观察到。忽略不治疗和手术切除被认为是犬治疗选择，而全身糖皮质激素被认为对猫无效。

This case presented for intense pain, which along with the Horner’s syndrome and rear leg weakness, initially led to suspicion of neurological disease. Although primary neurological disease was eliminated, we cannot say with certainty that rear leg weakness did not contribute to a traumatic event that affected the pinna. However, owing to the lack of acute clinical signs and absence of trauma reported, this potential aetiology is considered unlikey. Histopathological findings were consistent with auricular chondritis, with no infectious agents detected. Although cultures were not performed and infectious disease cannot be eliminated completely, it is considered unlikely given the response to immunosuppressive therapy. Likewise, because immunofluorescence staining was not performed, autoantibodies directed against the cartilage remains a possibility given previous reports and response to therapy, yet this is considered unlikely in this case as a consequence of the unilateral presentation.

本病例表现为剧烈疼痛，同时伴有霍纳氏综合征和后腿无力，最初怀疑为神经系统疾病。虽然原发性神经系统疾病已被排除，但我们不能肯定地说，后腿无力是与患病耳廓有关的创伤性事件。然而，由于缺乏急性临床症状和没有外伤报告，我们认为不可能是这种潜在病因。组织病理学检查结果与耳软骨炎一致，没有发现感染性病原。虽然没有进行细菌培养，不能完全排除感染性疾病，但考虑到使用免疫抑制治疗的效果，认为没有感染可能。同样，由于未进行免疫荧光染色，根据以前报道和治疗效果，针对软骨的自身抗体仍然是可能的，但由于是单侧表现，这种情况被认为是不可能的。

This report suggests that pain may be a prominant finding in canine auricular chondritis similar to the finding in cats. In addition, monotherapy with systemic prednisone led to quick and complete resolution of clinical signs, suggesting that steroids may be a reasonable therapeutic option. Further evaluation of canine auricular chondritis is needed, including evaluation with immunofluorescence to investigate the primary aetiology.

该报告表明，疼痛可能是犬耳软骨炎的明显表现，这种表现与猫相似。此外，全身性使用泼尼松单一治疗可使临床症状迅速缓解并完全消失，提示类固醇可能是一种合理有效治疗选择。有必要对犬耳软骨炎进行进一步评估，包括免疫荧光评估，以调查原发病因。

Figure 1. Photograph showing a Labrador retriever dog’s thickened, erythematous right pinna.

图1：一只拉布拉多猎犬的增厚的、发红的右耳廓照片。

Figure 2. Transverse image from a computerized tomography scan revealing thickened right pinna without other soft tissue or bone abnormalities in a Labrador retriever dog.

图2：一只拉布拉多猎犬的CT扫描的横断面影像，显示右耳廓增厚，未见其他软组织或骨组织异常。

Figure 3. A photomicrograph of the histopathological findings from a Labrador retriever dog with auricular chondritis. Necrosis of the auricular cartilage, lymphoplasmacytic inflammation and multinucleated histiocytic cells are present. Haematoxylin and eosin, x200.

图3：一只患耳软骨炎的拉布拉多猎犬的组织病理学显微照片。可见坏死的耳软骨、淋巴浆细胞性炎症反应和出现多核组织细胞。HE染色200倍放大。

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