Fungal Malignant Otitis Externa with Facial Nerve Palsy: Tissue Biopsy Aids Diagnosis

Fungal malignant otitis externa (FMOE) is a serious and potentially life-threatening condition that is challenging to manage. Diagnosis is often delayed due to the low sensitivity of aural swabs and many antifungal drugs have significant side effects. We present a case of FMOE, where formal tissue sampling revealed the diagnosis and the patient was successfully treated with voriconazole, in addition to an up to date review of the current literature. We would recommend tissue biopsy of the external auditory canal in all patients with suspected FMOE in addition to routine microbiology swabs. 1. Introduction Malignant otitis externa (MOE) remains a relatively uncommon condition but can lead to serious morbidity or mortality as diagnosis is often delayed leading to initially ineffective treatment [1]. The infection begins in the external auditory canal, typically presenting with severe otalgia and purulent otorrhoea; it can rapidly spread via the ear canal soft tissue to the temporal bone resulting in osteomyelitis and subsequent cranial nerve palsies and intracranial infection. The prevalence of bacterial MOE is not accurately documented [2] and it is unknown whether fungal MOE is a repercussion of unsuccessfully treated bacterial otitis externa or if it represents a de novo presentation of fungal disease. The most commonly reported pathogen in malignant otitis externa is Pseudomonas aeruginosa [2]. Aspergillus species and Candida albicans have been implicated in fungal MOE. There are 32 previously reported cases of fungal MOE, usually occurring in patients with some form of immunosuppression—typically diabetes, acquired immunodeficiency, or malignancy. We present a case of fungal malignant otitis externa complicated by a facial nerve palsy that proved very difficult to achieve a formal diagnosis. 2. Case An 83-year-old man with type 2 diabetes presented with right sided otalgia and otorrhoea; examination revealed granulation tissue inferiorly in his ear canal at the Osseochondral junction. A clinical diagnosis of malignant otitis externa was made. Pseudomonas aeruginosa was grown on microbiological culture of the discharge, sensitive to ciprofloxacin. His condition was successfully treated over a period of three months with oral and topical ciprofloxacin and he was discharged from clinic pain-free with an otoscopically normal canal. One year later, he presented with left-sided grade III facial nerve palsy and a painful left ear (note this is the contralateral side to the original presentation). The left ear was initially otoscopically normal. CT and MR