Malignant Otitis Externa-A Review

Objective: To review the literature about Malignant Otitis Externa. Methodology: A comprehensive review of existing knowledge that is available in literature has been summarised in this article. Results: There is a rising incidence of Malignant Otitis Externa in the developing countries, predominantly seen in elderly diabetics. The common organism isolated is Pseudomonas aeruginosa though other microbials have been described as a causative agent. Radioimaging such as Technitium 99m MDP Scintigraphy, Gallium 67 Single Photon Emission CT and Tc99m Sulesomab scan has been recently used to asses and monitor therapy. The treatment protocol involves initial management with intravenous antimicrobials, regular aural toileting with adjunctive Hyperbaric Oxygen therapy. Unresponsive patients require either a trial with antifungals or a tissue diagnosis to rule out other differentials. Surgery is no longer found to be a first line treatment of MOE. Conclusion: Malignant Otitis Externa is a highly fatal, necrotizing condition of the external auditory canal and temporal bone which is seen in elderly immunocompromised individuals. It is a highly aggressive skull base infection that is associated with high morbidity/mortality and cranial nerve complications. Although a variety of organisms such as Proteus mirabilis, Staphylococci, Klebsiella species and Aspergillus fumigatus have been implicated in the pathogenesis of MOE, Pseudomonas aeruginosa has been a predominant organism closely associated with MOE. With the advent of present day radiological imaging and effective antimicrobials coupled with a high index of suspicion, the mortality rate has been reduced from an alarming 50% to 20% over the past few decades.