Otitis media with effusion (OME) is fluid in the middle ear space without symptoms of an acute ear infection. Unlike children with an acute ear infection, children with OME do not act sick.

Almost every acute ear infection is followed by days or weeks of OME. In addition, many people develop OME without first having acute inflammation.

OME occurs when the Eustachian tube, which connects the inside of the ear to the back of the throat, becomes blocked. This tube helps drain fluids to prevent them from building up in the ear. The fluids drain from the tube and are swallowed.

When the Eustachian tube is partially blocked, fluid builds up in the middle ear. Bacteria that are already inside the ear become trapped and begin to multiply.

The following can cause swelling of the lining of the Eustachian tube, leading to increased fluid:

• Allergies
• Irritants (especially cigarette smoke)
• Respiratory infections

The following can cause the Eustachian tube to close or become blocked:

• Drinking while lying on your back
• Sudden increases in air pressure (such as descending in an airplane or on a mountain road)

Although many things can lead to a blocked tube, getting water in a baby's ears will not.

OME is most common in winter or early spring, but can occur at any time of year. It can affect people of any age, although it occurs most often in children under age 2. (It is rare in newborns.)

Younger children get OME more often than older children or adults for several reasons:

• The tube is shorter, more horizontal, and straighter, making it easier for bacteria to enter.
• The tube is floppier, with a tinier opening that's easy to block.
• Young children get more colds because it takes time for the immune system to be able to recognize and ward off cold viruses.

The fluid in OME is often thin and watery. It used to be thought that the longer the fluid was present, the thicker it became. ("Glue ear" is a common name given to OME with thick fluid.) However, it is now believed that the thickness of the fluid has more to do with the particular ear than with how long the fluid is present.

OME often does not have obvious symptoms.

Older children and adults often complain of muffled hearing or a sense of fullness in the ear. Younger children may turn up the television volume.

Most often OME is diagnosed when the health care provider examines the ear for another reason, such as at a well-child physical.

A general ear examination may show:

• Air bubbles
• Dullness
• Fluid behind the eardrum
• Reduced movement of the eardrum

A test called tympanometry is a more accurate tool for diagnosing OME. The results of the test can help tell the amount and thickness of the fluid.

An acoustic otoscope or reflectometer is a more portable device that accurately detects the presence of fluid in the middle ear.

An audiometer or some other type of formal hearing test may help the health care provider decide what treatment is needed.

In otherwise healthy children, the first treatment is to change environmental factors, if possible. This includes:

• Avoiding cigarette smoke
• Encouraging breastfeeding for infants
• Reconsidering group day care

If the child has allergies, staying away from triggers (such as dust) can help.

Most often the fluid will clear on its own. You doctor may suggest waiting and watching to see if the condition worsens.

If the fluid is still present after 6 weeks, treatment might include:

• Further observation
• A hearing test
• A single trial of antibiotics (if not given earlier)

If the fluid is still present at 12 weeks, the child's hearing should be tested. If there is significant hearing loss (> 20 decibels), antibiotics or ear tubes might be appropriate.

If the fluid is still present after 4 - 6 months, tubes are probably needed even if there is no significant hearing loss. Laser myringotomy is a newer alternative to ear tube surgery.

Sometimes the adenoids must be removed to restore proper functioning of the Eustachian tube.

Otitis media with effusion usually goes away on its own over a few weeks or months. Treatment may speed up this process. Glue ear may not clear as quickly as OME with a thinner effusion.

OME is usually not life threatening, but it may result in serious complications. If there is fluid in the middle ear, hearing will be affected. Hearing problems can interfere with language development in children. Any fluid that lasts longer than 8-12 weeks is cause for concern.

• Acute ear infection
• Cyst in the middle ear
• Permanent damage to the ear with partial or complete hearing loss
• Scarring of the eardrum (tympanosclerosis)
• Speech or language delay

Note: Permanent hearing loss is rare, but the risk increases the more ear infections a child has.

Call your health care provider if:

• You suspect you or your child might have otitis media with effusion. Continue to monitor the condition until the fluid has disappeared.
• New symptoms develop during or after treatment for this disorder.

Prevention tips:

• Avoid irritants such as cigarette smoke, which can interfere with Eustachian tube function.
• Identify and avoid any allergans that may lead to your child's OME.
• Consider a smaller day care, especially in the winter months. Day care centers that have six or fewer children result in fewer ear infections.
• Wash hands and toys frequently.
• Use air filters and get fresh air to help decrease exposure to airborne germs.
• Avoid overusing antibiotics. The overuse of antibiotics breeds increasingly resistant bacteria.
• Breastfeeding for even a few weeks will make a child less prone to ear infections for years.
• The pneumococcal vaccine can prevent infections from the most common cause of acute ear infection (which leads to OME). The flu vaccine can also help.

American Academy of Family Physicians; American Academy of Otolaryngology - Head and Neck Surgery; American Academy of Pediatrics Subcommittee on Otitis Media With Effusion. Otitis media with effusion. Pediatrics. 2004;113:1412-1429.

Paradise JL, Feldman HM, Campbell TF, Dollaghan CA, Rockette HE, Pitcairn DL, et al. Tympanostomy tubes and developmental outcomes at 9 to 11 years of age. N Engl J Med. 2007;356:248-261.