Infection: Ear Infection

Definition
Description
Demographics
Causes and Symptoms
Diagnosis
Treatment
Prognosis
Prevention
The Future
For more information

Definition

Ear infections are caused by either a bacterial or fungal infection of the outer ear or a viral or bacterial infection of the middle ear. The outer ear is the visible part of the ear plus the ear canal, a small passage that conducts sound waves from the outside to the middle ear.

The middle ear is a group of structures that include the eardrum and three small bones called ossicles that convey sound energy from the ear canal to the structures of the inner ear. The middle ear is connected to the upper throat by a passageway called the Eustachian tube, which has two major functions: to equalize air pressure between the middle ear and the air outside the body and to drain fluid or mucus from the middle ear into the throat.

Description

Infection of the outer ear, or otitis externa, is a skin infection caused by bacteria or fungi that get into the skin of the ear canal through a scratch or other small break in the skin. The skin lining the ear canal is very thin and easily damaged. If a person goes swimming, takes a shower, or is

exposed to hot, humid weather, bacteria or fungi in the ear canal can rapidly multiply and cause an inflammation of the skin. Because the skin of the ear canal is closely attached to the underlying bone, the inflammation can cause severe pain and swelling that may be sudden. The swelling of the skin of the canal may lead to temporary hearing loss.

Infection of the middle ear, or otitis media, is often a complication of the common cold. It begins when cold viruses (or sometimes bacteria) enter the Eustachian tube from the upper throat and produce inflammation and swelling in the tube. Fluid builds up behind the eardrum when the Eustachian tubes are blocked by swelling; this is called an effusion. The Eustachian tubes can also be blocked by swollen adenoids, pieces of tissue that are part of the immune system and lie at the very back of the nasal passages. If the adenoids become infected, they can swell and block the Eustachian tubes.

Doctors usually distinguish between otitis media with effusion (OME) and acute otitis media. In OME, the fluid that builds up behind the eardrum is not itself infected; in acute otitis media, the collection of fluid itself has become infected by bacteria. The difference is important because it affects the treatment of the earache.

Demographics

Infection of the outer ear is common. In the United States, it is more common in the summer months and in the warmer and more humid parts

of the country and is more likely to affect adolescents and young adults than very young children.

Infection of the middle ear, however, is much more common in young children than in older children or adults. There are two reasons for this. First, the immune systems of young children are less well developed than those of older children; second, the Eustachian tubes in young children enter the upper throat at a lower angle than in older humans. This difference makes it easier for disease organisms to stay in the tubes and cause inflammation and swelling rather than being carried downward into the throat.

Infections of the middle ear are very common in children between six months and three years of age. According to the National Institutes of Health (NIH), 50 percent of all children in the United States have at least one episode of otitis media by the time they are a year old, and 80 percent have an episode by three years of age. The costs of treating these infections and their complications come to $4 billion each year.

Otitis media is more common in the fall and winter months in the United States. It is somewhat more common in boys than in girls and is more common in Native Americans than in children of other racial groups. The reasons for these differences are not known.

Factors that increase a child's risk of middle ear infections include:

• Heredity. Repeated infections of the middle ear are known to run in some families, although no specific genes have been linked to otitis media.
• Having a cleft palate.
• Day care. Children in day care settings are exposed to common colds and other upper respiratory infections that can lead to otitis media.
• Exposure to tobacco smoke or air pollution.
• Feeding position. Babies who are fed from a bottle while lying down are at greater risk of ear infections than those who are held upright.
• Family history of frequent ear infections.
• Use of a pacifier.
• History of allergies.

Causes and Symptoms

Ear infections are caused by disease organisms causing tissue inflammation and fluid buildup in the skin of the outer ear or the structures of the middle ear.

The symptoms of otitis externa may include:

• Sudden onset of pain
• Intense pain when the outer ear is pulled or moved
• Itching
• Swelling of the outer ear or nearby lymph nodes in the neck
• Feeling of fullness in the ear
• Temporary loss of hearing or feeling that sounds are muffled
• Pus draining from the ear
• Red or flaky skin on the outside of the ear

The symptoms of otitis media may include:

• Intense crying in very young children
• Tugging or pulling at the ear
• Fever
• Irritability and headaches
• Trouble sleeping or poor feeding
• Nausea and vomiting (in small infants)
• Hearing loss
• Ringing or buzzing sounds in the ear
• Fluid draining from the ear (This symptom usually indicates that the eardrum has ruptured.)

If the child has otitis media with effusion, there may be a slight hearing loss or no symptoms at all.

Diagnosis

The diagnosis of an ear infection is based on a combination of the patient's age, history, and a physical examination in the doctor's office. Otitis externa can usually be diagnosed by simple movement of the outer ear, which will typically produce intense pain. When the doctor looks into the ear with an otoscope, the ear canal will look red and swollen, and there may be pus present. The doctor may take a sample of the pus or fluid and send it to a laboratory for culture.

In the case of otitis media, the doctor will use a pneumatic otoscope to examine the child's ear. This specialized otoscope allows the doctor to puff a small amount of air into the middle ear to see whether there is fluid behind the eardrum. If fluid is present, the eardrum will not move.

Another test known as tympanometry may also be done to measure the movement of the eardrum. In tympanometry, a small plug is inserted into the outer ear and air is blown into the ear canal to evaluate the movement of the eardrum.

If there is evidence of hearing loss, the child may be referred to an audiologist for hearing tests.

Treatment

Treatment of an infection of the outer ear may involve one or more of the following:

• Cleaning the outer ear with a cotton swab or suction device to remove flaky skin and pus or other fluid.
• Antibiotic ear drops to fight infection. If the ear canal is swollen shut, the doctor may insert a wick that will allow the drops to penetrate the full length of the ear canal.
• Aspirin or ibuprofen to relieve pain and reduce inflammation.
• Ear drops containing a steroid medication to reduce itching and tissue swelling.

The patient will be told to avoid swimming or scuba diving until the infection is cleared and to keep water out of the ears while bathing or showering.

Treatment of otitis media depends in part on whether the patient has otitis media with effusion (OME) or a bacterial infection. If the swelling of the Eustachian tube and the fluid buildup are caused by a virus, antibiotics will not help. About 80 percent of children with otitis media do not have a bacterial infection and will recover without antibiotics.

The American Academy of Pediatrics (AAP) recommends a wait-and-see approach for the first two to three days to see whether the infection will improve without antibiotics. Parents can give the child nonaspirin pain relievers to relieve fever, apply warm washcloths to the outer ear, or use anesthetic ear drops for pain. Antibiotics are usually prescribed, however, for babies younger than six months; older children who have had two or more ear infections within a month; children in severe pain; or children with a fever of 102°F (38.9°C) or higher.

The doctor may recommend surgical treatment if the child has recurrent infections of the middle ear or if the infections are not cleared

by antibiotics. In this type of surgery, a small drainage tube is inserted through the eardrum to drain fluid and to equalize the pressure between the middle ear and outer ear. The tubes usually fall out on their own as the child grows. If the child's Eustachian tubes are blocked by swollen adenoids, the doctor may recommend surgical removal of the adenoids.

Prognosis

Infections of the outer ear usually clear up completely in about a week without long-term complications. In some cases, however, people develop a chronic infection of the outer ear that extends to inflammation of the surrounding skin. A few people, most often those with diabetes or a weakened immune system, may develop a severe infection of the bone and cartilage near the outer ear that can cause severe pain and spread to the brain. This rare but potentially life-threatening complication requires treatment with intravenous antibiotics and sometimes surgery.

Most cases of otitis media improve within two to three days and clear up completely in a week or two without complications. If fluid remains behind the eardrum for long periods of time, however, it may eventually cause hearing loss. Another possible complication of recurrent or untreated otitis media is the spread of infection into air cells called mastoids in the bones around the base of the skull, a condition known as mastoiditis.

Prevention

Infections of the outer ear can be prevented by using ear plugs when swimming, avoiding swimming in polluted water, drying the ears after swimming or showering, and avoiding the use of foreign objects to clean wax out of the ears. It is very easy to damage the skin of the ear canal in this way.

Infections of the middle ear can be prevented by keeping a child away from children with colds or upper respiratory infections; by not exposing the child to tobacco smoke; by feeding the child in an upright position; and by breastfeeding the child for the first six months of life. Some doctors also recommend giving the child Prevnar, a vaccine that protects against pneumonia and appears to reduce the risk of otitis media as well.

The Future

Ear infections are likely to continue being common health problems in children and adolescents. Researchers are comparing the effectiveness of tube placement versus removal of the adenoids in treating otitis media. They are also studying the effectiveness of the pneumonia vaccine in preventing infections of the middle ear.

SEE ALSO Cleft lip and palate; Common cold; Smoking

WORDS TO KNOW

Effusion: The medical term for an abnormal collection of fluid in a body cavity.

Eustachian tube: The passageway that connects the middle ear with the upper throat.

Otitis: The medical term for inflammation of the ear.

Otoscope: An instrument with a light and magnifying lens that allows a doctor to examine the eardrum and ear canal.

For more information

BOOKS

Friedman, Ellen M., and James P. Barassi. My Ear Hurts!: A Complete Guide to Understanding and Treating Your Child's Ear Infections. New York: Simon and Schuster, 2001.

Weisman, Roanne, and John D. Mark. Your Sick Child: Fever, Allergies, Ear Infections, Colds, and More. Deerfield Beach, FL: Health Communications, 2006.

PERIODICALS

Tarkan, Laurie. “Ear Infections Too Often Misdiagnosed, Then Overtreated.” New York Times, January 22, 2008. Available online at http://health.nytimes.com/ref/health/healthguide/esn-earinfections-ess.html (accessed July 18, 2008).

WEB SITES

American Academy of Family Physicians (AAFP). Earaches in Children. Available online at http://familydoctor.org/online/famdocen/home/children/parents/common/ent/055.html (updated February 2008; accessed July 19, 2008).

American Academy of Otolaryngology—Head and Neck Surgery. Ear Infections and Earache. Available online at http://www.entnet.org/HealthInformation/earInfections.cfm (updated January 2008; accessed July 19, 2008).

KidsHealth. Swimmer's Ear. Available online at http://kidshealth.org/kid/ill_injure/aches/swimmers_ear.html (updated May 2008; accessed July 19, 2008).

National Institute on Deafness and Communication Disorders (NIDCD). Otitis Media (Ear Infection). Available online at http://www.nidcd.nih.gov/health/hearing/otitism.asp (updated July 2002; accessed July 19, 2008).

National Library of Medicine (NLM). Otitis Media. Available online at http://www.nlm.nih.gov/medlineplus/tutorials/otitismedia/htm/index.htm (accessed July 19, 2008). This is an online tutorial with voiceover with options of a self-playing version, a text version, or an interactive version with questions.