water-resistant, acidic, antibacterial substance that prevents maceration Swimmers ear develops when water in the ear disrupts the protective cerumen layer Disruption of the cerumen layer may occur in attempts to remove water in the canal or to relieve pruritus Insertion of cotton swabs or other objects may cause injury, creating portals of entry for bacteria in the external ear Ear pain and sometimes visible ear discharge are the usual symptoms of otitis externa Examination reveals an erythematous, swollen external canal filled with debris or purulence Traction on the auricle causes pain with otitis externa, a finding that can help distinguish it from otitis media with perforation Gentle removal of debris, instillation of topical antibiotics, and systemic analgesia are the usual treatment When swelling is so severe that topical antibiotics may not reach the more proximal portion of the canal, a wick may be inserted to facilitate antibiotic entry Systemic antibiotics are indicated if there is extensive cellulitis spreading beyond the external canal Otitis externa is usually polymicrobial, but S aureus and P aeruginosa are important pathogens to cover, and polymyxin/neomycin or fluoroquinolone otic drops are the preferred treatment Otitis externa with P aeruginosa can be fulminant and necrotizing Recalcitrant cases of otitis externa, especially if pruritus is a prominent symptom, may require evaluation for fungal disease (otomycoses) or deeper infection FIGURE 58.1 Ear pain algorithm AOM, acute otitis media; CNS, central nervous system; TMJ, temporomandibular joint; OME, otitis media with effusion ACUTE OTITIS MEDIA