Malignant otitis externa (MOE) is a fatal disease, in which inflammation spreads from the external auditory canal to the skull base, resulting in skull base osteomyelitis. We report an atypical case of MOE without otalgia.
The patient, a 76-year-old man with a history of diabetes mellitus developed left otorrhea, and 3 months later, he presented with facial paralysis and dysphagia. He was referred to our department due to intractable otitis externa. The left external auditory canal was filled with white otorrhea fluid and was circumferentially swollen with granulation tissue. Pseudomonas aeruginosa was cultured from the otorrhea fluid. Examination revealed left facial and glossopharyngeal nerve paralyses. Computed tomography (CT) showed soft tissue involvement with bony destruction in the left external auditory canal and surrounding tympanic cavity. Despite these severe inflammatory lesions, the patient had no otalgia. Left tympanomastoidectomy was performed to rule out malignancy. Histopathology revealed no malignancy, but inflammatory cell infiltration. Postoperative magnetic resonance imaging (MRI) showed inflammation extending to the left skull base. Therefore, the patient was diagnosed as having MOE and was started on treatment with ofloxacin ear drops, intravenous levofloxacin 500 mg/day, and ceftazidime 6 g/day. Since the inflammatory findings were trending towards improvement, the intravenous antibiotics were discontinued after 6 weeks. Thereafter, the patient received oral levofloxacin for about 2 years. The patient has been under follow-up until date, without any evidence of relapse. However, the left facial and glossopharyngeal paralyses have still not fully recovered.
MOE is occasionally difficult to differentiate from simple otitis externa. It is important to recognize the possibility of atypical MOE without otalgia and to diagnose and treat this condition before any cranial nerve palsies become manifest.
