Rubin Grandis Jennifer, Branstetter Barton F, Yu Victor L
Department of Otolaryngology, University of Pittsburgh School of Medicine, PA, USA.
Lancet Infect Dis. 2004 Jan;4(1):34-9. doi: 10.1016/s1473-3099(03)00858-2.
Malignant (necrotising) external otitis is an invasive infection of the external auditory canal. Although elderly patients with diabetes remain the population most commonly affected, immunosuppressed individuals (eg, from HIV infection, chemotherapy, etc) are also susceptible to malignant external otitis. Pseudomonas aeruginosa is isolated from the aural drainage in more than 90% of cases. The pathophysiology is incompletely understood although aural water exposure (eg, irrigation for cerumen impaction) has been reported as a potential iatrogenic factor. The typical patient presents with exquisitely painful otorrhoea. If untreated, cranial neuropathies (most commonly of the facial nerve) can develop due to subtemporal extension of the infection. The diagnosis of malignant external otitis is based on a combination of clinical findings, an increased erythrocyte sedimentation rate, and radiographic evidence of soft tissue with or without bone erosion in the external canal and infratemporal fossa. Treatment consists of prolonged administration (6-8 weeks) of an antipseudomonal agent (typically an orally administered quinolone). With the introduction and widespread use of both oral and topical quinolones, there are reports of less severe presentation of malignant external otitis and even the emergence of ciprofloxacin resistance. Reservation of systemic quinolones for the treatment of invasive ear infections is recommended.
恶性（坏死性）外耳道炎是外耳道的一种侵袭性感染。虽然糖尿病老年患者仍是最常受影响的人群，但免疫抑制个体（如因感染艾滋病毒、接受化疗等）也易患恶性外耳道炎。超过90%的病例中耳道引流物分离出铜绿假单胞菌。尽管耳部接触水（如因耵聍嵌塞进行冲洗）已被报道为一种潜在的医源性因素，但病理生理学仍未完全明确。典型患者表现为耳痛剧烈且有耳漏。若不治疗，感染可经颞下扩展导致颅神经病变（最常见为面神经病变）。恶性外耳道炎的诊断基于临床症状、红细胞沉降率升高以及外耳道和颞下窝软组织有或无骨质侵蚀的影像学证据。治疗包括长期（6 - 8周）使用抗假单胞菌药物（通常为口服喹诺酮类）。随着口服和局部用喹诺酮类药物的引入和广泛使用，有报道称恶性外耳道炎的表现较轻，甚至出现了环丙沙星耐药性。建议保留全身用喹诺酮类药物用于治疗侵袭性耳部感染。
