Otitis Externa

Otitis extern a is an acute or chronic inflammation of the skin of the external ear canal and auricle. It occurs most commonly during the summer but can occur at any time of the year.

With treatment, acute otitis externa usually subsides within 7 days; however, it may become chronic and tends to recur. Severe, chronic otitis externa may reflect underlying diabetes mellitus, hypothyroidism, or nephritis.

Other names for this disorder are external otitis and swimmer's ear.

Causes

Several things can make Otitis Externa more likely including the following:

• If you swim or shower a lot, too much water can get into your ears. Water removes the protective ear wax. Then it's easier for germs and fungus to grow.
• Cleaning your ears can remove the protective wax layer and lead to infection.
• If you injure the skin in the ear canal by putting your finger or some object in your ear, an infection can develop in the canal.
• Skin conditions such as psoriasis that occur in other parts of the body can also occur in the ear canal and cause Otitis Externa.

Signs and Symptoms

A review of the patient history usually shows repeated exposure to ear trauma, water, use of earphones, or allergic response to hair spray, dye, or other hair-care products. The patient also may relate a history of mild to severe ear itching or pain (or both) that is aggravated by jaw motion, clenching the teeth, opening the mouth, or chewing.

Inspection may reveal a swollen, inflamed ear canal and an ear discharge that may be foul-smelling. In chronic otitis externa, inspection shows a thick, red epithelium in the ear canal. The patient may complain of increased pain or itching on palpation or manipulation of the pinna or tragus.

Otoscopy reveals a swollen external ear cana: (sometimes to the point of complete closure), periauricular lymphadenopathy (tender nodes in front of the tragus, behind the ear, or in the upper neck) and, occasionally, regional cellulitis.

Fungal otitis externa may be asymptomatic, although A. niger may appear on otoscopy as a black or gray, inkblotlike growth in the ear canal.

Diagnostic tests

Audiometric testing may reveal a partial hearing loss. Microscopic examination or culture and sensitiviy tests can be used to identify the causative organism and determine antibiotic treatment. In fungal otitis externa, removal of the growth reveals thick, red epithelium.

Treatment

Treatment - emphasizing site care and drug therapy - includes:

• cleaning debris from the ear canal with suction and small cotton-tipped applicators under direct visualization through an ear speculum
• instilling antibiotic or anti-inflammatory drops-a combination of polymyxin B, neomycin, and hydrocortisone (Cortisporin Otic solution) to manage gram-negative and gram-positive organisms and to decrease inflammation
• inserting an ear wick or a piece of medicine-soaked cotton into the ear (when the canal is moderately or severely swollen) for 24 to 48 hours.
• administering analgesics as appropriate
• administering systemic antibiotics to combat systemic signs such as fever. Corticosteroids may be used with antibiotic drops.

Surgery may be needed to excise and drain an abscess.

For the patient with a fungal infection, treatment includes:

• cleaning the ear carefully
• applying a keratolytic or 2% salicylic acid in cream containing nystatin for candidal organisms
• instilling slightly acidic eardrops to create an unfavorable environment in the ear canal for most fungi as well as Pseudomonas.

In chronic otitis externa, treatment involves:

• cleaning the ear and removing debris
• instilling antibiotic eardrops or applying antibiotic ointment or cream (neomycin, bacitracin, or polymyxin B, possibly combined with hydrocortisone). An ointment containing phenol, salicylic acid, precipitated sulfur, and petroleum jelly, which produces exfoliative and antipruritic effects, also may be used.

For mild chronic otitis externa, treatment includes:

• instilling antibiotic eardrops once or twice weekly
• wearing specially fitted earplugs while showering, shampooing, or swimming.

Prevention

The following steps will help you avoid otitis externa:

• Try to prevent water, shampoo or other products getting in your ears when you are showering or bathing. Putting a piece of cotton wool covered in petroleum jelly into the outer ear can help.
• Don't push the corners of your towel into the ears to dry them after washing and swimming. Let the ears dry naturally. If you swim regularly, you may want to think about using a swimming cap that covers the ears, or wearing ear plugs.
• Don't use cotton buds to clean the ear canal. Wax works its way out naturally, and cotton buds should only be used to sweep around the outer ear.