Otitis media with effusion

Definition
Otitis media with effusion (OME) is an inflammatory condition of the middle ear with fluid accumulation. It usually develops after an episode of acute otitis media (ear infection). Sometimes, the fluid accumulation in the middle ear can cause hearing loss. OME affects children more often than adults. It often clears up on its own, but different treatment options are available.

Causes/associated factors
The middle ear includes the eardrum and the space behind it, which is usually filled with air. When acute otitis media occurs, pus from the infection fills this space in the middle ear. After the infection clears up, pus or fluid may still remain. This is called an effusion. For most children who have effusion, it will clear up on its own within three months. But for some, the fluid may remain for a long time and affect their hearing.



Effusion may occur from chronic obstructive problems of the eustachian tube. Infants and young children have short, narrow eustachian tubes that tend to plug more easily during colds than in older children and adults. Children also have larger adenoids (lymph node tissues in the back of the throat, close to the eustachian tubes, that help filter infections from the body). Large or infected adenoids can interfere with the natural ventilation provided by the eustachian tubes, creating a suitable environment for infection.


Transmission
Otitis media (with or without effusion) is not contagious, but the preceding respiratory infections usually are. As an adult, your body can often fight these infections and prevent otitis media. As a child or an older person with lowered resistance, however, direct contact with infected respiratory secretions or inhaling infected respiratory droplets coughed or sneezed into the air can easily lead to a respiratory infection that may become an ear infection. Knowing when someone with a respiratory infection is contagious can be difficult. It depends on what type of organism is causing the illness and whether it's viral or bacterial. A good rule of thumb is to consider someone contagious for a few days before and after the onset of symptoms and any time a fever is still present.

Signs/symptoms
OME often has no symptoms, but there may be a sensation of a plugged ear, a ringing or other unusual sound in the ear, vertigo (dizziness) or mild to moderate hearing loss. In children who cannot verbalize these symptoms, be on the lookout for signs of decreased hearing, such as not responding to quiet sounds or sitting too close to the television.

Diagnosis
The doctor can evaluate the middle ear using a few different ways:
A simple otoscope lets the doctor look inside the ear and evaluate the condition of the eardrum. A retracted (bending backward) or convex (curved) eardrum is often seen with effusion. Sometimes, air fluid levels or air bubbles can be seen.

A pneumatic otoscope allows the doctor to determine how well the eardrum is able to move. This tool allows a small puff of air to be delivered onto the eardrum itself, causing it to move. With fluid in the middle ear, movement of the eardrum is impaired.

A tympanometer helps the doctor evaluate air pressure in the ear by using a special electronic ear device that's similar to a pneumatic otoscope. Air pressure readings are printed on a graph and are calculated to determine how well the eardrum moves. With an effusion, air pressure findings and eardrum movement ability are usually abnormal.
If you or your child have frequent ear infections, you may be referred to an otolaryngologist (an ear, nose and throat specialist) or an audiologist (a medical professional who specializes in evaluating hearing status).


Treatment
Watchful waiting
Since the majority of all effusions clear up on their own within three to four months, the middle ear fluid should be reassessed. If the effusion remains after three to four months, a change in treatment is often necessary. An evaluation by an otolaryngologist may be needed, especially if hearing loss is suspected or diagnosed.

Studies have shown that antihistamines and decongestants do not help clear OME.

Benefits: Watchful waiting postpones or avoids more invasive, potentially costly and unnecessary interventions.

Risks: Serial checkups may be necessary during the observation period to monitor for new infections or the development of significant hearing loss.

Tympanostomy
The Agency for Healthcare Research and Quality recommends the placement of ventilating tubes when OME has persisted for four months along with associated hearing impairment in both ears of 20 decibels or more. This procedure is termed tympanostomy or myringotomy with tube placement. First, a small cut is made in the eardrum to remove the fluid in the middle ear. Then a small tube is inserted into the eardrum to ventilate the middle ear and restore hearing. The tubes are left in place until they fall out on their own, usually in about six to 12 months,

Benefits: Middle ear fluid is removed and hearing is restored immediately.

Risks: The procedure is done under general anesthesia, which comes with rare risks of neurological impairment and death. A persistent perforation of the eardrum may result after the tubes are removed. Repeat surgeries may be needed to replace the tubes. Other risks include hearing loss from scar tissue, eardrum atrophy, cholesteatoma (a skin growth in the middle ear) and a condition called tympanosclerosis (hardening in the eardrum). Also recent studies have demonstrated that ear tubes may have no clear, long-term benefit over watchful waiting.

Removal of adenoids
Sometimes, adenoids are surgically removed in a procedure called adenoidectomy to prevent repeated episodes of otitis media, typically after age 2. This procedure may be done at the same time as a tympanostomy or myringotomy.

Benefits: Future episodes of otitis media may be prevented.

Risks: The debate as to the effectiveness of this procedure for OME continues. There are potential complications from general anesthesia, as well as the possibility of hemorrhage and infection.


Complications
Persistent effusion may lead to retraction (a shortening or drawing backwards) and atrophy of the eardrum. These changes can lead to a skin growth in the middle ear (cholesteatoma) or changes in the middle ear bones (ossicles).
The impact of hearing loss from effusion on speech and language development is controversial. Most recent studies have found no effect on speech and language development.


Prevention
Since middle ear infections can predispose a child to develop middle ear fluid, it's important to minimize the risks for respiratory infections. Follow the immunization schedule recommended by your doctor to help prevent upper respiratory infections in your child. If possible, avoid day care settings to help minimize exposure to viruses and bacteria. Exposure to cigarette smoke contributes to the development of ear infections, so keep children out of smoke-filled environments.
Breastfeeding is associated with lower rates of otitis media. Bottle-fed infants may be more prone to ear infections if left lying down with a bottle. Because of the angle of the eustachian tube in an infant, this position allows for the backward flow of formula into the eustachian tube and middle ear space. To avoid this, never leave a child lying down with a bottle.