Malignant Otitis Externa in an Adult Diabetic Patient Caused by Escherichia coli: a Case Report

Abstract

Abstract Introduction: Malignant otitis externa (MOE) is commonly presented as invasive external otitis resistant to local treatment that classically affects elderly diabetic patients. Case presentation: We presented a 55-year-old man with a history of diabetes mellitus (DM) and ear scratching, initially manifesting with left-sided nocturnal otalgia, purulent otorrhea, and external auditory canal (EAC) edema. A diagnosis of MOE was made based on Levenson's criteria and radiological findings. Antibiotics were given intravenously based on bacterial cultures from ear swabs, with repeated cultures growing Escherichia coli (E. coli). The patient's MOE caused by E. coli improved after two months of ear toilets, DM management, parenteral and local antibiotics, and hyperbaric oxygen therapy (HBOT). We detected that the MOE was caused by self-inflicted local trauma to the EAC on the same side as the dominant hand. Conclusion: The isolation of E. coli from the EAC as the causative organism of MOE with a favorable response to HBOT as an adjunction to antibiotic therapy was previously unreported and could present a novel treatment strategy.