3.02 Otitis Externa (Swimmer's Ear)
Presentation
The patient complains of ear pain, always uncomfortable and
sometimes unbearable, often accompanied by drainage and a blocked
sensation, sometimes by fever. When the condition is mild or chronic
there may be itching rather than pain. Pulling on the auricle or pushing
on the tragus of the ear classicly causes increased pain. The tissue
lining the canal may be swollen and in severe cases the swelling can
extend the the soft tissue surrounding the ear. Tender erythematous
swelling or an underlying furuncle may be present, and it may be
pointing or draining. The canal may be erythematous and dry or it may
be covered with fuzzy cotton-like grayish or black fungal plaques. Most often, the
canal lining is moist, covered with purulent drainage and debris, and
cerumen is characteristically absent. The canal may be so swollen that
it is difficult or impossible to view the tympanic membrane, which
when seen often looks dull.
What to do:
- Suction out the debris and drainage present in the canal. Irrigation
can be most effective in cleaning out the canal. Inspect for the presence
of any foreign body.
- Incise and drain any furuncle that is pointing or fluctuant.
- If the ear canal is too narrow for medication to flow freely, insert a
wick. Best is the Pope ear wick (Merocel), about 1 by 10 mm of
compressed cellulose, which is thin enough to slip into bn occluded
canal, but expands when wet. If not available, try using alligator forceps
to insert quarter-inch gauze (but this is more painful). After a wick is
inserted, water must be kept out of the ear, and the patient must be
instructed to use soft wax ear plugs while showering.
- Prescribe a topical steroid solution for instillation down the wick (Otic
Tridesilon Solution, Vosol HC, Acetasol HC, Corticosporin Solution or
Suspension), every six to eight hours for the next 7-14 days. (Clear
solutions are usually used, because they do not obscure follow up
examination, but if there might be a perforation of the tympanic
membrane, use a less-irritating suspension. Ophthalmic gentamycin
solution is a good choice for pseudomonas. The antifungal cresyl
acetate solution (Cresylate) may be used for a purely fungal infection.)
- With moderate to severe pain and slft tissue swelling, or other signs
of cellulitis, prescribe an appropriate analgesic (e.g., acetaminophen,
ibuprofen, naproxen, hydrocodone or oxycodone) and an antibiotic (e.g.,
trimethaprim plus sulfamethoxyzole, ciprofloxacin, dicloxicillin or
cefadroxil) and have the patient use warm, moist compresses to help
relieve any pain or swelling
- Provide follow up in one to two days for removal of the wick and
remaining debris from the ear canal.
- Have the patient use a prophylactic 2% acetic acid solution (e.g., Otic
Domeboro Solution or half-strength vinegar) after swimming or bathing
when the initial therapy has been completed.
What not to do:
- Do not use oral antibiotics for simple otitis externa without evidence
of cellulitis or concurrent otitis media.
- Do not use topical antibiotics for prophylaxis. Long- term use of any
topical antibiotics can lead to a fungal superinfection.
- Do not instill medication without first cleansing the ear canal, unless
restricted because of pain.
- Do not expect medicine to enter a swollen-shut canal without a wick.
- Do not use ear drops containing neomycin, which sometimes causes
allergic dermatitis.
Discussion
Otitis externa has a seasonal occurrence, being more frequently
encountered in the summer months, when the climate and contaminated
water will most likely precipitate a fungal or Pseudomonas aeruginosa
bacterial infection. Various dermatoses, diabetes, aggressive ear cleaning
with cotton-tipped applicators, previous external ear infections and
furunculosis also predispose patients to developing otitis externa.
The healthy ear canal is coated with cerumen and sloughed
epithelium. Cerumen is warer-repellant and acidic, and contains a
number of antimicrobial substances. Repeated washing or cleaning can
remove this defensive coating. Moisture retained in the ear canal is
readily absorbed by the stratum corneum. The skin becomes macerated
and edematous and the accumulation of debris may block gland ducts,
preventing further production of the protective cerumen. Finally,
endogenous or exogenous organizms invade the damaged canal
epithelium and cause the infection.
Malignant or necrotizing external otitis is a life-threatening
condition that occurs primarily in elderly diabetic patients as well as
any immunocompromised individual. The pathognomonic sign of
malignant external otitis is the presence of active granulation tissue in
the ear canal. Early consultation should be obtained if there is any
suspicion of this condition in a susceptable patient with a draining ear.
The ear is innervated by the fifth, seventh, ninth and tenth
cranial nerves and the second and third cervical nerves. Because of this
rich nerve supply, the skin is extremely sensitive. Otalgia may arise
directly from the seventh cranial nerve (geniculate ganglion), ninth
cranial nerve (tympanic branch), the external ear, the mastoid air cells,
the mouth, teeth, or esophagus. Ear pain can result from sinusitis,
trigeminal neuralgia and temperomandibular joint dysfunction opr be
referred from disorders of the pharynx and larynx. A mild pain referred
to the ear may be felt as itching, cause the patient to scratch the ear
canal, and present as an external otitis. When the source of ear pain is
not readily apparent, the patient should be referred for a more complete
otolaryngologic investigation.
Table of Contents
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Craig Feied, MD
Mark Smith, MD
Jon Handler, MD
Michael Gillam, MD
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