Jan. 4, 2006

Brian N. Corwell, M.D. and Brian Boyls-White, BS, ATC
University of Maryland Sports Medicine

Otitis externa, also called swimmer's ear, is an inflammatory condition of the outer surface of the tympanic membrane, external ear canal, or auricle. This condition is usually associated with recent swimming. Otitis externa has multiple causes, including traumatic or infectious, inflammatory, or dermal disease. This review will focus on the most common cause affecting swimmers: infectious otitis externa secondary to bacterial infection. The most common cause of otitis externa is excessive moisture, which removes cerumen(ear wax) and decreases the acidity of the external ear canal, creating a growing environment for bacteria. Local trauma, mechanical removal of cerumen, and insertion of foreign objects into the ear can cause otitis externa. Avoidance of these precipitants is the cornerstone of effective treatment in all patients, especially the competitive swimmer. Otitis externa can be very painful and disabling to an athlete. The diagnosis of otitis externa is clinical, underscoring the importance of the history and physical exam. Treatment involves cleaning, antibiotics and pain control. Most athletes will be able to return to play in approximately 3 days.

Anatomy and Physiology
The ear canal is lined with special cells and glands that provide a natural protective barrier against infection. Cerumen repels water and inhibits bacterial growth. Bacteria can be introduced when this protective layer is disrupted such as by increased temperature, humidity, breakdown of the canal wall lining following prolonged exposure to moisture and by local trauma (e.g., overzealous use of cotton swabs). Minimal inflammation can cause significant pain.

History
Athletes with otitis externa (OE) are most likely to present for medical care with two characteristic complaints: Otalgia, or ear pain, and Otorrhea, discharge in or emanating from the ear canal. The otalgia can range from mild itching to pain exacerbated by ear motion/chewing to severe pain at rest. The initial symptom of pruritus may have caused the patient to scratch their ear a few days before the onset of pain and drainage. Other symptoms such as a sense of ear fullness and decreased or loss of hearing may result from complete auditory canal occlusion secondary to inflammation and discharge/debris. Pain can be very severe and disabling in advanced cases. Over a third of patients with OE interrupt their daily activities for a median of 4 days, with 21 percent requiring bed rest.

Physical Exam
Depending on the severity of the OE, the ear canal may appear red and swollen, with traction on the ear lobe causing severe pain. Discharge often has a characteristic cheesy white, green/gray, or watery appearance but the color can be variable. If the ear drum can be visualized, it is often thickened, erythematous and may be covered with the flat vesicles of the canal lining. There should be no evidence of middle ear fluid and the drum should be mobile with pneumatic insufflation, differentiating OE from otitis media. In severe disease the ear canal may be completely occluded with accompanying surrounding auricular erythema.

Differential Diagnosis
The most important clinical distinction is differentiating otitis externa from otitis media (middle ear infection). This is important as the two entities have completely different treatments. The distinction may be complicated by the presence of EAC fluid originating from a perforated ear drum caused by otitis media. Visualization of the drum is necessary to exclude otitis media but this can be made difficult when the EAC is filled with discharge from moderate to severe OE. Other conditions to be considered which may present in a similar manner include wisdom tooth eruption.

Treatment
Treatment of otitis externa has three main components: ear canal hygiene, bacterial elimination and analgesia.

Canal hygiene involves thorough yet atraumatic cleaning of the discharge and debris in the EAC. Canal debris and discharge interfere with management and treatment in three ways. First, it continues to maintain the moist canal environment. Secondly, it interferes with visualization of the ear drum. Finally, it serves as a mechanical obstruction for the delivery of topical antibiotics. Three common techniques, though quite useful for cerumen disimpaction, should never be employed. As the canal epithelium is at greater risk of direct injury from local trauma, removal should not be performed with a curette. Also, unless one is certain that the TM is intact, flushing of the canal should never be attempted. Doing so may cause damage to the ossicles and vestibular apparatus leading to hearing loss, dizziness and vertigo. Finally, lavage with hydrogen peroxide may be irritating to the inflamed tissue and inadequately kills the underlying bacteria.

Instead, cleansing is best performed by two techniques. If the equipment is available, suctioning under direct visualization is best. Alternatively, gentle "dry-mopping" of secretions with a cotton swab or a small tuft of cotton attached to a wire applicator under direct visualization may be attempted. Sometimes, thorough cleansing of debris that may be dried and crusted can prove too difficult. Also, cleaning may be extremely painful to the patient. In these cases, the discharge should be left in place. In cases of severe swelling, a cylindrical cotton, sponge or hydroxycellulose wick should be gently inserted approximately 10mm into the swollen, debris-filled canal. The purpose of the wick is to facilitate drainage, reduce edema and serve as a conduit for application of topical antibiotics. The patient may apply the topical antibiotic to the absorbent wick, thereby transporting medication to the part of the canal that lies distal to the obstruction. The wick can usually be removed after 48 to 72 hours. Often times, the wick spontaneously falls out as inflammation resolves.

Once canal hygiene has been accomplished, bacterial elimination is the next consideration. Though simple acidification of the canal with 2% acetic acid solution can be effective treatment, it has a lower cure rate and a longer duration of symptoms. The need for rapid resolution of symptoms, the higher potential of sooner re-exposure to moisture and water, the potential irritation to already inflamed tissue and issues of return to play in the competitive athlete all argue for stronger first-line treatment. There are many available effective topical antibiotic solutions for the treatment of OE. Only the two most commonly used treatments will be discussed.

Neomycin-polymixin B/hydrocortisone (Cortisporin Otic) has been used extensively for years with good results but has been associated with both hypersensitivity reactions and ototoxicity. This data is based on very few human cases and comes largely from animal studies. Despite this association, Cortisporin is used by 95% of otolaryngologists. This medication comes in two forms, a suspension and a solution. The suspension has less chance of middle ear penetration and resultant ototoxicity and therefore should be used in cases of unconfirmed or suspected TM perforation.

In contrast, topical fluoroquinolones (ciprofloxacin and ofloxacin) have decreased risk of these side effects, are equally effective, and likely have greater compliance as they require less frequent application. They are, however, approximately double the cost. Of these two agents, Ofloxacin otic should be used in cases of known or suspected TM rupture. Otherwise, ciprofloxacin should be used preferentially as it contains hydrocortisone (as does Cortisporin Otic), a topical steroid. Studies show that clinical symptoms of OE resolve sooner with addition of a topical steroid-containing agent.

Treatment should continue for approximately 5 to 7 days or for at least two days beyond symptom resolution. Severe infections may require 10-14 days of treatment. Warming the bottle of drops in the hands before instillation minimizes discomfort and dizziness. Four drops of Cortisporin Otic are placed in the affected ear 4 times daily. Five drops of the topical fluoroquinolones are instilled every 12 hours. Medication should be instilled into an upright-facing ear (i.e. patient on his/her side) with this position held for 3-5 minutes. If tolerated by the patient, absorption and delivery can be facilitated by slight posterior and superior traction on the ear during antibiotic delivery. Over-treatment may lead to dermatitis or fungal colonization. Therefore, as a precaution, prescription topical antibiotics should be nonrefillable and only an amount sufficient for a single course of treatment should be dispensed (10mL). Oral antibiotics are unnecessary in most cases of OE and are reserved for patients with invasive infection such as with a fever (Temp >101), local cellulitis, or in those who are at risk of further complications (immunocompromised, diabetics, those taking systemic steroids). When unable to fully exclude otitis media on the basis of history and physical exam, treatment for OE and otitis media can be administered concomitantly. Because of the incidence of external otitis in patients with diabetes, a blood glucose level should be obtained in all patients with severe otitis externa. Analgesia is the final important component of therapy. The pain associated with the acute infection may be so severe that systemic analgesics are necessary. Some combination of a nonsteroidal anti-inflammatory drug (NSAID) and a narcotic should be prescribed depending on the severity of the infection.

The significance of proper patient disposition and follow-up cannot be overemphasized. Patients with severe OE, those requiring wick placement or those with obstructed canals preventing visualization of the TM should be re-evaluated in 24 hours, with continued follow-up every 1 to 2 days until clinical improvement is noted. This is also an opportune time to perform a more thorough otoscopic examination if unable to do so initially. Patients should be made cognizant of the reasons to seek further care, such as fever, headache, hearing loss or worsening pain. As most patients improve greatly within the first 48-72 hours following treatment initiation, failure to do so should call the diagnosis into question and prompt reevaluation.

Prevention
Because of the high rate of recurrence in patients who participate in water sports on a regular bases, prevention is imperative and should be emphasized by the athletic trainer and physician. Potential local trauma may be caused to the skin of the canal by overzealous cleaning and should therefore be avoided. Also, frequent washing of the ear canal with soap makes the canal less acidic and therefore more prone to infection. Patients who produce excessive cerumen and require an alternative to local cleaning may benefit from a ceruminolytic agent such as Cerumenex. If local trauma has occurred in predisposed individuals, one may consider use of an acidifying agent with hydrocortisone for prophylaxis. After swimming, the canal can be dried using a hair dryer on the lowest heat setting. Immediately after swimming, some authors recommend application of drops containing equal parts rubbing alcohol (isopropyl), to dry the canal, and vinegar, to lower the pH of the canal. Several prepared formulations exist in most pharmacies, such as a solution containing 2% acetic acid mixed with 85% isopropyl alcohol. In addition, swimmers may benefit from barrier protection. The benefit of impermeable earplugs is controversial. While properly fitted plugs will keep the canal dry, they may also cause cerumen impaction and act as a local irritant. They have even been shown to predispose the athlete to otitis externa. A tight fitting bathing cap may offer better protection.

Complications
Although uncommon in the young, healthy athlete, malignant otitis externa must always be considered in any patient with very severe OE, pain out of proportion to exam findings or OE recalcitrant to treatment. Malignant otitis externa is a life threatening extension of external otitis into the ear cartilage and adjacent mastoid or temporal bone with an associated mortality as high as 53%. There may be associated headache, cranial nerve palsy and other systemic manifestations of infection. It occurs most commonly in the elderly patient with diabetes mellitus and the immunocompromised. Further, an otolaryngologist should always be involved early in the patient's course as surgical debridement is occasionally necessary. If this diagnosis is being considered, the patient should be sent to the local emergency department for antibiotics, a computed tomographic (CT) scan and likely hospitalization.

Return to play
There are no established NCAA return to play guidelines. Non-competitive individuals should refrain from swimming for 1 week. Competitive swimmers can return after 2 to 3 days of treatment and full resolution of pain.