Necrotizing otitis externa caused by Staphylococcus epidermidis

Abstract

We present a case of malignant necrotizing otitis externa (MNOE) caused by Staphylococcus epidermidis, which is usually a non-pathogenic microorganism. The patient is an otherwise healthy, nondiabetic 58-year-old white man. Contributory history began in 1994 after surgery for bilateral exostoses of the external auditory canals. Between April 1994 and May 1998 persistent otalgia occurred, with progressive mixed hearing losses, purulent discharge from both ears, spontaneous perforations of the tympanic membranes and ulceration of canal wall skin. From the beginning, Staph. epidermidis was isolated in all but one culture, but was not recognized as the pathological agent because of the presence of other more frequently involved bacteria and fungi. After multiple intravenous and oral antibiotics and antifungal treatments failed, further management involved frequent debridement of both external auditory canals and tympanic membranes, right tympanoplasty, bilateral mastoidectomy, revision tympanomastoidectomies and left modified radical mastoidectomy. Antistaphylococcal therapy including ceftazidime, vancomycin, teicoplanin, clindamycin and rifampicin was tried. Following the modified radical radical mastoidectomy, normalization of the status of his ears took approximately 2 months and has since remained stable to date. His left ear is deaf because of vancomycin administration, while magnetic resonance imaging and gallium scintigraphy have shown persistent inflammation of the skull base.