January 20, 2007

External Ear Disorders


The outer ear consists of the external part of the ear (pinna or auricle) and the ear canal (external auditory meatus. Disorders of the outer ear include blockages, infections (external otitis and perichondritis), eczema, and tumors. The outer ear is also prone to certain types of injury. a

Earwax (cerumen) may block the ear canal. Even large amounts of wax often produce no symptoms. Symptoms can range from itching to a loss of hearing. A doctor may remove the earwax by gently flushing out the ear canal with warm water (irrigation). However, if a person has had a perforated eardrum, irrigation is not used because water can enter the middle ear if the perforation is still present. Similarly, irrigation is not used if there is any discharge from the ear, because the discharge may be coming from a perforated eardrum. In these situations, a doctor may remove earwax with a blunt instrument, an instrument with a loop at the end, or a vacuum device.

Earwax solvents help soften wax, but they usually must be followed by irrigation, because the solvent rarely dissolves all of the wax. People should not attempt earwax removal at home with cotton swabs, bobby pins, pencils, or any other implements. Such attempts usually just pack the wax in more and can damage the eardrum. Soap and water on a washcloth provide adequate external ear hygiene

Other blockages can occur when people, particularly children, put foreign objects, such as beads, erasers, and beans, into the ear canal. Usually, a doctor removes such objects with a blunt hook or small vacuum device. Sometimes metal and glass beads can be flushed out by irrigation, but water causes some objects, such as beans, to swell, complicating removal. Objects that are deep in the canal are more difficult to remove because of the risk of injury to the eardrum. A general anesthetic is used when a child does not cooperate or when removal is particularly difficult.

Insects, particularly cockroaches, may also block the ear canal. To kill the insect, a doctor fills the canal with mineral oil or a numbing agent. This measure also provides immediate pain relief and enables the doctor to remove the insect.

External Otitis
External otitis is infection of the ear canal.

External otitis may affect the entire canal, as in generalized external otitis, or just one small area, as in a boil (furuncle) or pimple.

A variety of bacteria or, rarely, fungi can cause generalized external otitis. Certain people, including those who have allergies, psoriasis, eczema, or scalp dermatitis, are particularly prone to external otitis. Injuring the ear canal while cleaning it or getting water or irritants such as hair spray or hair dye in the canal often leads to external otitis. External otitis is particularly common after swimming in fresh water pools, in which case it is sometimes called swimmer's ear. Earplugs and hearing aids make external otitis more likely, particularly if these devices are not properly cleaned.

Symptoms and Diagnosis
Symptoms of generalized external otitis are itching and pain. Sometimes an unpleasant-smelling white or yellow discharge drains from the ear. The ear canal may have no swelling, slight swelling, or in severe cases be swollen completely closed. If the ear canal swells or fills with pus and debris, hearing is impaired. Usually, the canal is tender and hurts if the external ear (pinna) is pulled or if pressure is placed on the fold of skin in front of the ear canal. To a doctor looking into the ear canal through an otoscope (a device for viewing the canal and eardrum), the skin of the canal appears red and swollen and may be littered with pus and debris.

Boils cause severe pain. When they rupture, a small amount of blood and pus may leak from the ear.

Prevention and Treatment

Swimmer's ear may be prevented by putting drops of a solution containing half rubbing alcohol and half vinegar in the ear before and after swimming. The person should avoid swimming in polluted water, using hair spray, and spending much time in warm, humid climates.

Attempting to clean the canal with cotton swabs interrupts the normal, self-cleaning mechanism and can push debris toward the eardrum, where it accumulates. Also, these actions may cause minor damage that predisposes to external otitis.

To treat generalized external otitis from any cause, a doctor first removes the infected debris from the canal with suction or dry cotton wipes. After the ear canal is cleared, hearing often returns to normal. Usually, a person is given antibiotic ear drops to use several times a day for up to a week. Some ear drops also contain a corticosteroid to reduce swelling and analgesics to reduce pain. Often, external otitis is successfully treated with ear drops containing vinegar.
Bacteria do not grow as well once the normal acidity of the ear canal is restored. If the ear canal is very swollen, a doctor inserts a small wick in the canal to allow the drops to penetrate.

Analgesics such as acetaminophen codeine may help reduce pain for the first 24 to 48 hours, until the inflammation begins to subside. An infection that has spread beyond the ear canal cellulitis may be treated with an antibiotic given by mouth.

Treatment of boils depends on how advanced the infection is. In an early stage of infection, a heating pad can be applied for a short time and analgesics can be given to help relieve pain; the heat may also help speed healing. A boil that has come to a head is cut open to drain the pus. An antibiotic is then applied directly to the area or given by mouth.

A number of different injuries can affect the outer ear. A blunt blow to the external ear can cause bruising between the cartilage and the layer of connective tissue around it (perichondrium). When blood collects in this area, the external ear becomes swollen and purple. The collected blood (hematoma) can cut off the blood supply to the cartilage, allowing that portion of the cartilage to die, leading in time to a deformed ear. This deformity, called a cauliflower ear, is common among wrestlers, boxers, and rugby players.

A doctor cuts open the hematoma and removes the blood with suction. After the hematoma is empty, the doctor applies a compression dressing, which is left on for 3 to 7 days to keep the hematoma from coming back. The dressing keeps the skin and perichondrium in their normal positions, allowing blood to reach the cartilage again.

If a cut (laceration) goes all the way through the ear, the area is cleansed thoroughly and the skin is sewn back together and a dressing is applied to protect the area and allow the cartilage to heal. The cartilage is not sewn.

A forceful blow to the jaw may fracture the bones surrounding the ear canal and distort the canal's shape, often narrowing it. The shape can be corrected surgically.

Perichondritis is infection of the cartilage of the external ear.

Injury, burns, insect bites, ear piercing, or a boil on the ear may cause perichondritis. The infection also tends to occur in people whose immune system is weakened and in people who have diabetes. The first symptoms are redness, pain, and swelling of the ear. The person may have a fever. Pus accumulates between the cartilage and the layer of connective tissue around it (perichondrium). Sometimes the pus cuts off the blood supply to the cartilage, destroying it and leading eventually to a deformed ear. Although destructive and long-lasting, perichondritis tends to produce only mild discomfort.

A doctor makes an incision to drain the pus, allowing blood to reach the cartilage again. Antibiotics are given by mouth for milder infections and intravenously for severe infections. The choice of antibiotic depends on how severe the infection is and which bacteria are causing it.

Tumors of the ear may be noncancerous (benign) or cancerous (malignant). Most ear tumors are found when a person sees them, or when a doctor looks in the ear because the person notices his hearing seems decreased.

Noncancerous tumors may develop in the ear canal, blocking it and causing hearing loss and a buildup of earwax. Such tumors include small sacs filled with skin secretions (sebaceous cysts), osteomas (bone tumors), and growths of excess scar tissue after an injury (keloids). The most effective treatment is surgical removal of the tumor. After treatment, hearing usually returns to normal.

Basal cell and squamous cell cancers are common skin cancers that often develop on the external ear after repeated and prolonged exposure to the sun. When these cancers first appear, they can be successfully treated by removing them surgically or by applying radiation therapy. More advanced cancers may require surgical removal of a larger area of the external ear.

Ceruminoma (cancer of the cells that produce earwax) develops in the outer third of the ear canal and can spread. Ceruminomas have nothing to do with earwax buildup. Treatment consists of removing the cancer and the surrounding tissue surgically

Adapted from: Merck & Co., Inc