Section 19. Ear, Nose, and Throat Disorders

Chapter 219. Outer Ear Disorders

Topics: Introduction | Blockages | External Otitis | Perichondritis | Tumors | Injury

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.

Causes

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 or 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 (see Section 18, Chapter 211)) 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.