February 7, 2011 by dailybolusoflr
Otitis externa is an infection of the external auditory canal (EAC). This infection is most commonly noted in patients who have chronic exposure to water (such as swimmers) and the more severe form, malignant otitis externa, in immunocompromised patients such as those with diabetes.
Patients usually complain of ear pain, itching, drainage and can note a feeling of fullness in the ear or decreased hearing.
The classic finding noted in patients which is said to be diagnostic is pain when traction is applied to the external ear. Other physical exam findings are drainage/debris in the external canal, edema of the canal and in severe cases, complete obliteration of the external canal due to edema/debris. Otitis externa is differentiated from perforated otitis media in that in a patient with performated OM, the external canal is not painful or swollen.
Patients with malignant otitis externa may develop cellulitis extending from the area, necrosis of local tissues, and evidence of local extension as evidenced by cranial nerve involvement.
Treatment involves local debridement (as needed) and topical antibiotics. Ciprofloxacin 0.3%/dexamethasone 0.1% otic suspension or neomycin-polymyxin B-hydrocortisone are appropriate choices. For canals that are completely occluded with edema, a wick may be placed to facilitate delivery of the drops to the affected tissue.
Linda Regan, MD FACEP
Program Director, Emergency Medicine Residency
Johns Hopkins Medical Institutions