Pearl of the Day: Otitis Externa

Otitis Externa (OE) Etiology - Pseudomonas aeruginosa, Staphylococcus aureus - occurs with conditions that alter the normal external ear canal flora (e.g., exposure to moisture, direct trauma to ear)

Signs/Symptoms - early stages:  ear fullness, itching - erythematous ear canal, tender pinna and tragus - pain exacerbated by manipulation of auricle or range of motion of TMJ - usually normal tympanic membrane

Diagnostic Criteria - rapid onset within 48 hours in the past 3 weeks of at least one primary symptom (otalgia, itching, fullness) AND - one primary sign (tenderness of tragus/pinna or diffuse ear canal edema/erythema)

Treatment - attempt to remove debris to increase efficacy of topical medication - steroid-antibiotic combination drops (e.g., ciprofloxacin with dexamethasone) - for mild OE (without TM perforation), may use acidifying therapy (e.g., boric acid, acetic acid) - cotton wick can be placed to get drops deeper toward tympanic membrane

Cotton Wick - can be made from narrow gauze (0.25 inch packing) or from hard sponge material that expands (e.g., Merocel) - medication is placed onto external end of ear wick, which is then pulled into the ear canal - antibiotic drops should be placed 2 - 4 times daily - may fall out as edema decreases - should be removed after 2 - 3 days

Surgical Debridement and Drainage - reserved for necrotizing OE, complications of OE, significant amount of discharge, fungal infections - failure of prolonged antibiotic therapy

Systemic Antibiotics - only for extension of disease outside of ear canal and/or host is immunocompromised - if started, should consider cultures of ear canal

Complications - external canal stenosis - requires debridement - abscess formation (usually with S. aureus infections) - requires I&D by ENT - malignant OE/necrotizing OE from P. aeruginosa caused by local invasion into skull and underlying structures

Discharge Instructions - keep ear canal dry - place earplug or cotton ball coated with petroleum jelly in ear canal when bathing/showering - may resume aquatic activities once infection is treated (usually 4 - 5 days)

Resources Peer IX Tintinalli's Emergency Medicine, 8th Edition