Otitis Media

How Do We Hear?

The ear consists of three major parts: the outer ear, the middle ear, and the inner ear. The outer ear includes the pinna (the visible part of the ear) and the ear canal. The outer ear extends to the tympanic membrane (eardrum), which separates the outer ear from the middle ear. The middle ear is an air-filled space located behind the eardrum. It contains 3 tiny bones, the malleus, incus, and stapes, which transmit sound from the middle ear to the inner ear. The middle ear is connected to the back of the nose and upper throat by the Eustachian tube. This tube ventilates the ear and equalizes the air pressure in the middle ear to the outside air pressure. The inner ear contains the hearing (cochlea) and balance (labyrinth) organs. The auditory nerve connects the cochlea to the brain.

In a healthy ear, sound waves striking the eardrum send vibrations through the 3 tiny bones in the middle ear. Movement of these bones transmits sound waves across the middle ear to the cochlea of the inner ear. In the cochlea, the sound is transformed into nerve impulses that travel to the brain. In this manner, the sound is perceived.

What is Otitis Media?

Otitis Media is an infection or inflammation of the middle ear that usually follows a buildup of fluid in the middle ear space. This condition occurs when the Eustachian tube becomes inflamed following a cold, sinus or throat infection, allergic reaction, or is blocked by enlarged adenoid tissue. Fluid accumulating in the middle ear cannot drain properly and may become infected. Bacteria are the primary causes of otitis media and are detected in 70% of cases. The most common microorganisms detected are Haemophilus influenzae and Streptococcus pneumonia. Less common bacteria involved are Moraxella catarrhalis and Streptococcus pyogenes. Viruses are not usually a direct cause of otitis media, but play a major role by causing inflammation in the nasal passages and impairing defense systems, such as cilia, in the ear. Respiratory syncytial virus (RSV), Influenza virus, and Rhinovirus are the prime suspects. Although this condition occurs most often in children one to three years of age, older children and adults may develop it as well.

Why is Otitis Media So Common in Children?

There are various reasons why children are more likely to suffer from Otitis Media than adults. First, young children have more trouble fighting infections because their immune systems are still developing.

Another reason is related to a child's Eustachian tube, which is shorter and more horizontal than in adults. This contributes to Otitis Media in the following ways. The Eustachian tube usually opens regularly to ventilate or replenish the air in the middle ear and to equalize its air pressure to that of the environment. However, a blocked Eustachian tube, either due to swelling of its lining or plugged with mucus, cannot open properly to ventilate the middle ear. This in turn impedes the drainage of fluid from the middle ear tissue, which collects in the middle ear. Also, the angle of the Eustachian tube in children makes it easier for bacteria from the nose and throat to enter the middle ear.

Enlarged adenoids represent another factor that makes children more susceptible to Otitis Media. Adenoids are positioned in the back of the upper part of the throat near the Eustachian tubes. When enlarged, they can interfere with the Eustachian tube opening. In addition, adenoids may themselves get infected, thereby spreading infection into the Eustachian tubes.

What are the Risk Factors for Developing Otitis Media?

The greatest risk factor for Otitis Media is Eustachian Tube blockage due to an upper respiratory illness such as common cold, flu, throat, or sinus infection.

Additional risk factors include:
Age: Infants and young children are more prone as discussed earlier. Also, the younger a child is at the time of the first ear infection, the greater the chance he or she will have repeated infections.

Enlarged Adenoids: Contribute to ear infections as discussed earlier.

Bottle-feeding: Babies, who are bottle-fed, especially while they are lying down, are more susceptible to ear infections than breastfed babies. Also, breast milk provides immunity

Colds & Allergies: Often lead to ear infections by causing swelling of the Eustachian tube.

Cigarette smoke: Children inhaling tobacco smoke have a higher risk of developing health problems, including ear infections.

Socioeconomic Status: Children from low socioeconomic groups have a higher incidence than those living in wealthier communities.

Gender: Boys are more apt to have infections than girls.

What are the Effects of Otitis Media?

Otitis Media causes severe earache but may result in serious complications if not treated. An untreated infection can travel from the middle ear to the nearby parts of the head, including the brain. Persistent fluid in the middle ear hampers the movement of the eardrum and the three middle ear bones resulting in mild to moderate hearing loss. Although this hearing loss is usually temporary, untreated otitis media may lead to permanent hearing impairment. Persistent fluid in the middle ear and chronic otitis media can reduce a child's hearing at a time that is critical for speech and language development, leading to speech and language disabilities.

What are the Signs and Symptoms of Otitis Media?

Otitis Media is often difficult to detect because most children affected by this disorder do not yet have sufficient speech and language skills to tell someone what is bothering them.

Common symptoms of Otitis Media include:

• Muffled hearing

• Sensation of ear blockage or pressure

• Ear pain

• Fever

• Ear discharge

Common signs to look for are:

• Unusual irritability

• Difficulty in sleeping

• Tugging, pulling or scratching one or both ears

• Unresponsiveness to quiet sounds

• Inattentiveness

• Misunderstanding directions

• Sitting too close to the television

• Wanting the television or radio louder than usual

• Nausea

• Vomiting

• Dizziness or loss of balance

On the other hand, there may be no symptoms at all. At times, middle ear fluid may be discovered incidentally during a routine check-up.

How does a Child's Physician Diagnose Otitis Media?

Ear infections require immediate attention by a pediatrician, primary care physician, or an otolaryngologist (ear, nose, and throat specialist). In addition, evaluation by an audiologist and a speech-language pathologist is important if a child has repeated episodes of infection and/or chronic fluid in the middle ear otitis media is suspected, the child's ears are examined with an otoscope to check for redness or fluid behind the eardrum.

Pneumatic otoscopy

maybe performed to check for middle ear fluid. During this procedure a puff of air is blown into the ear and movement of the eardrum is observed. An eardrum with fluid behind it does not move as well as an eardrum with air behind it. An audiogram or hearing test is performed to measure the degree of hearing loss.

Tympanometry

measures eardrum motion and the middle ear pressure to determine how well the Eustachian tube is functioning. If a speech delay is suspected, a speech and language evaluation should be considered. An ear swab from the ear discharge may be taken to determine the culture and sensitivity of the infecting microorganism, depending on which the appropriate antibiotic is prescribed.

In certain situations, a CT Scan of the head may be helpful to determine if the infection has spread beyond the middle ear.

What is the Treatment of Otitis Media?

Medical treatment

Prompt treatment of middle ear infections with antibiotics is vital to prevent complications. Amoxicillin or amoxicillin-clavulanate are the recommended antibiotics. Trimethoprim-sulfamethoxazole is useful for people allergic to penicillin. In resistant cases, newer generation cephalosporins are recommended. Oral antibiotics can be given for five to seven days in children over two years old. A full ten-day course of antibiotics, however, should still probably be used for very young children and for those with complications.

Analgesics (pain relievers) may be given to reduce the discomfort. Antihistamines, decongestants, and steroids have not been proven to work in children for the treatment of otitis media.

Surgical treatment

Once the infection clears, fluid may remain in the middle ear. This situation is termed serous otitis media or otitis media with effusion. Middle ear fluid that is not infected may disappear after several weeks; alternatively, it may persist for several months. If the fluid persists for more than three months and is associated with a loss of hearing, the insertion of a tympanostomy tube is suggested.

A procedure called myringotomy is performed where a tiny incision is made in the child's eardrum and fluid in the middle ear is gently sucked out. A small metal or plastic tympanostomy tube is then placed through the eardrum to prevent the myringotomy from closing and to help clear the middle ear fluid. This procedure is done under general anesthesia. Once the fluid is evacuated from the middle ear, the child's hearing often returns to normal. The tubes cannot be seen or felt while in place. Most types of tympanostomy tubes usually stay in place for six to twelve months and fall out spontaneously once the incision heals.

Tympanostomy tubes play an important role in keeping the ear healthy. They help prevent the buildup of middle ear fluid and thus reduce the rate of middle ear infection. They also allow the middle ear pressure to equilibrate with the atmospheric pressure and thus optimize hearing. Some children may need to have the operation repeated if the fluid re-accumulates after the tube comes out. While the tubes are in place, water should be kept out of the ears. It is recommended that a child with tubes wear special ear-plugs while swimming or bathing so that water does not enter the middle ear.

Additional treatment strategies for otitis media

If the child has enlarged or infected adenoids, the otolaryngologist may recommend an adenoidectomy at the same time that the tubes are inserted.

Are there any Preventive Measures for Otitis Media?

Children in group care settings as well as children who are exposed to cigarette smoke are more prone to middle ear infections. Infants who nurse from a bottle also appear to develop otitis media more frequently. Thus, when bottle feeding your child, hold his or her head above the stomach level during feeding. This can help keep the Eustachian tubes from getting blocked. The best hope for avoiding ear infections is the development of vaccines against the bacteria that most often cause otitis media. At present, they are still in the experimental stage.

What are the Possible Complications From Untreated Otitis Media?

While a child is young and at a higher risk for ear infections, it is important to know the symptoms of otitis media and to obtain proper treatment if an infection develops.

Although very rare, complications from untreated middle ear infections can include:

• Labyrinthitis: an infection of the inner ear that causes dizziness and imbalance

• Mastoiditis: an infection of the skull behind the ear

• Meningitis: an infection of the membranes around the brain and spinal cord

• Tympanosclerosis: scarring or thickening of the eardrum

• Facial paralysis

• Permanent hearing loss