Infectious Disease Compendium

Otitis externa

Diagnosis

Infection of the ear canal.

Epidemiologic Risks

Swimming, diabetes.

Microbiology

Acute localized otitis externa: S. aureus or group A Streptococcus.

Acute diffuse otitis externa (aka swimmer's ear): gram-negative bacilli, usually P. aerugenosa.

Invasive ("malignant") otitis externa: a necrotizing infection due to P. aerugenosa; it tends to invade into the brain and other structures around the middle ear. It is way bad.

Fungal otitis: Aspergillus spp.

Atypical mycobacteria are not uncommon, presenting with refractory otorrhea and lots of granulation tissue and are best treated with surgery (PubMed).

Empiric Therapy

It depends on the organism.

Swimmer Ear: Clean with hypertonic saline (3%) and cleansing with mixtures of alcohol (70% to 95%) and acetic acid. 10 days of a quinolone otic solution OR dicloxacillin-dexamethasone tic OR ear drops OR neomycin alone OR with polymyositis with hydro-cortisone. Oral therapy adds nothing to topical (PubMed).

Malignant Otitis Externa: DEBRIDE (Dee-breed. Dee bride is the one in Dee white dress). Note the capital letters, they are there for EMPHASIS. PLUS ear drops with antipseudomonal antibiotics PLUS iv therapy with a combination of ceftazidime OR cefepime OR piperacillin OR carbapenem for 4 to 6 weeks.

Oral ciprofloxacin if early and mild. Me? I would always go with the IV.

Last Update: 11/29/18.