Otitis externa

associated with swimming; retained foreign objects

s/s - itching and discharge; tenderness when tragus is manipulated

Causal organisms include Pseudomonas aeruginosa (most common cause), Staph. aureus (2nd most common), E. coli, Proteus vulgaris, coagulase-negative Staph, diphtheroids, Micrococcus spp., and viridans streptococci.

NO routine culture

Tx

Topical ofloxacin, ciprofloxacin, or polymyxin/neomycin

Add topical hydrocortisone (to decrease sweeling and itching)

Add acetic acid and water solution to reacidify the ear

Malignant otitis externa

in fact, osteomyelitis of the skull

is specifically caused by Pseudomonas aeruginosa, and tends to affect elderly diabetics and AIDS patients.

features severe and persistent earache, foul-smelling prurlent otorrhea and sense of fullness with red mass lesion of the external ear canal, which shows granulation tissue on biopsy.

may have conductive hearing defect

Complications:

may invade to temporal bone and skull base --> facial paralysis, vertigo, other cranial nerve abnormalities

also osteomyelitis of the skull base or TM joint can develop and present with pain exacerbated by chewing

Dx

Best initial test : CT or MRI