History
See the list below:
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Diabetes (90%) or immunosuppression (illness or treatment related)
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Severe, unrelenting, deep-seated otalgia
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Temporal headaches
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Purulent otorrhea
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Possibly dysphagia, hoarseness, and/or facial nerve dysfunction
Physical
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Inflammatory changes are observed in the external auditory canal and the periauricular soft tissue.
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The pain is out of proportion to the physical examination findings.
Marked tenderness is present in the soft tissue between the mandibular ramus and mastoid tip.
Granulation tissue is present at the floor of the osseocartilaginous junction. This finding is virtually pathognomonic of malignant external otitis (MEO). Otoscopic examination may also reveal exposed bone.
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The cranial nerves (V-XII) should be examined.
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Mental status examination should be performed. Deterioration of the mental status may indicate intracranial complication.
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The tympanic membrane is usually intact.
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Fever is uncommon.
Causes
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Diabetes (90% of patients)
Diabetes is the most significant risk factor for developing malignant external otitis (MEO).
Small-vessel vasculopathy and immune dysfunction associated with diabetes are primarily responsible for this predisposition.
The cerumen of patients with diabetes has a higher pH and reduced concentration of lysozyme, which may impair local antibacterial activity.
No difference in predisposition is found between diabetes types I and II.
The predisposition is not necessarily related to the severity of glucose intolerance or periods of hyperglycemia.
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Immunodeficiencies, such as lymphoproliferative disorders or medication-related immunosuppression
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AIDS
Malignant external otitis (MEO) associated with AIDS may have a different pathophysiology than classic malignant external otitis (MEO).
Patients present with similar symptoms but are generally younger and do not have diabetes.
Granulation tissue may be absent in the external auditory canal.
Pseudomonas is not necessarily the dominant causative organism.
Patients with AIDS generally have a poorer outcome than patients with diabetes.
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Aural irrigation: As many as 50% of cases of malignant external otitis (MEO) have been reported to be preceded by traumatic aural irrigation in patients with diabetes.
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Anatomy of the ear.
