Otitis externa, also known as swimmer's ear, is an infection of the outer ear canal caused by bacteria or fungi. Symptoms include ear pain, drainage from the ear, and sometimes fever. On examination, the ear canal appears swollen, red, and full of debris or drainage. Treatment involves cleaning the ear canal, inserting a wick to allow topical medications to penetrate, prescribing topical steroids and antibiotics, and following up within a few days to remove the wick and remaining debris. Proper treatment helps relieve symptoms while avoiding unnecessary oral antibiotics or long term topical antibiotics that could lead to fungal superinfections.

1. 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.

2. 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.