Necrotizing otitis externa: 19 cases' report

Abstract

Necrotizing otitis externa is an uncommon but severe infectious disease of the external auditory canal. Patients at risk are those immunodepressed or having diabetes. The causal germ is often Pseudomonas aeruginosa. Over a period of 10 years (1997-2006), we treated 19 patients: 94.7% had diabetes (insulin dependent in 6 cases). The causal germ was P. aeruginosa in 59% of cases. The pretherapeutic work-up included a computed tomography and a scintigraphy practiced in order to confirm diagnosis and assess the extension. Medical treatment was based on a parenteral antibiotic therapy using a third-generation cephalosporin and a fluoroquinolones. Local treatment of the auditory canal including cleaning and application of antimicrobial agents was performed in all the cases. Surgical debridement of soft tissue and infected bone was performed in one patient who did not respond to medical management. Repeated scintigraphies with gallium were used to follow the course under treatment in only three cases. We had a 89.4% cure rate with only three cases of recurrence. We reviewed the data in the literature on necrotizing otitis externa and present the important diagnostic, imaging, and therapeutic aspects of the disease.