Given these clinical findings, promptly order laboratory studies and imaging to confirm the diagnosis. The erythrocyte sedimentation rate and C-reactive protein level are typically elevated, and either can be used as a marker to follow treatment. Computed tomography (CT) helps to determine the location and extent of disease and is recommended as the initial diagnostic imaging modality for patients with suspected malignant otitis externa.12
Magnetic resonance imaging helps define soft-tissue changes, dural enhancement, and involvement of medullary bone, making this the preferred modality to monitor therapeutic response.12 Technetium bone scanning can also be used for the initial diagnosis (particularly if CT findings are normal and clinical suspicion is high) and for follow-up with treatment.
How to treat. Management involves a team approach with otolaryngology, radiology, neurology, endocrinology, and infectious disease specialists. Long term (6-8 weeks) antipseudomonal antibiotic treatment is typical.
Let culture results guide the choice of antibiotic. Fluoroquinolone therapy, usually ciprofloxacin, is used most often.12 Surgical intervention may be required for local debridement and drainage of abscesses. Close follow-up is necessary due to reports of recurrence up to 1 year after treatment. If left untreated, necrotizing otitis externa can lead to osteomyelitis, meningitis, septic thrombosis, cerebral abscess, and death.11
The relatively small diameter of the external auditory canal increases the risk for impaction of cerumen and foreign bodies. Cerumen impaction, in particular, is a common primary care complaint. Cerumen forms when glandular secretions from the outer two-thirds of the ear canal mix with exfoliated skin. It functions as a lubricant for the ear canal and as a barrier against infection, water accumulation, and foreign bodies.13
Continue to: What you'll see