Parents are often surprised to learn that their child has an ear infection. The infection is discovered during a visit for another purpose altogether. Even though silent ear infections cause no obvious symptoms, the child’s hearing is decreased while fluid remains in the ear. Moreover, OME often comes during the same months when children are trying to make sense of the language they hear around them.
Fluid in the middle ear, which often goes undetected for weeks or months at a time, is an important hidden problem. OME is the leading cause of surgery in children, because this silent occupant of our children’s ears can have lingering effects years after the fluid has disappeared.
First, let’s discuss the structure of the ear. There are three main parts to the ear – the outer, middle, and inner ear. The outer ear includes the pinna (the visible portion of the ear) and the external auditory canal (the small tube you see doctors looking into). The external auditory canal is separated from the middle ear by the tympanic membrane (eardrum). The middle ear consists of three tiny bones that transmit sound vibrations. It is connected to the back of the throat by a tiny tube called the Eustachian tube. The inner ear consists of a hollow region inside the skull where sound vibrations are converted into nerve impulses—messages that travel to the brain.
Otitis media with effusion (OME) is the name for fluid in the middle ear without other symptoms. This fluid generally contains bacteria. Nevertheless, children with OME act as if they feel well. Because it is often discovered on routine well-child checks, it is sometimes called silent otitis media.
Acute otitis media (AOM) refers to fluid in the middle ear accompanied by signs or symptoms of an ear infection, such as pain, redness, or a bulging eardrum. Children with AOM act sick (especially at night) and often have fevers.
When children are taken to the doctor because they seem like they have an ear infection, the visit is about AOM. This article is about OME.
The Eustachian tube is a small canal that connects the middle ear to the back of the throat. When bacteria make their way into the middle ear, they are supposed to be flushed out through the Eustachian tube. When the Eustachian tube is blocked, or isn’t functioning properly, bacteria-containing fluid can become trapped in the middle ear. This causes OME.
Getting soap or water in a child’s ears does not cause OME (though in older children it can cause swimmer’s ear – a superficial infection of the skin in the ear canal).
OME is most common in someone who already has a cold or other upper respiratory infection. It commonly precedes an acute ear infection (AOM). In addition, OME commonly lasts for weeks or months (an average of 21 days) after an episode of AOM has cleared up.
When an ear is rechecked after an acute ear infection, fluid is often still present after the symptoms have gone. This is OME and usually does not benefit from extra rounds of antibiotics.
Children get OME much more often than adults. The highest concentration of OME clusters in the window between 6 and 24 months of age.
About a third of children get no ear infections; about one third have occasional ear infections (three or less in any one year); and about one third are prone to ear infections.
Children may be prone to OME for a variety of reasons. Some have immature immune systems; some have Eustachian tubes that are shorter, narrower, or less efficient; and some have other reasons that the Eustachian tube is more likely to become inflamed or blocked (such as GE reflux, or environmental irritants like tobacco smoke). Up to 40 percent of children with OME have allergies as an underlying cause.
In the Northern hemisphere, OME is most common between December and March, even in areas with a mild climate. It is least common between July and September.
OME is also more common among children in daycare, especially if a child is exposed to more than six other children or if the child uses a pacifier.
Children with OME have fluid in the ear that causes mild hearing loss, but no other symptoms. An older child might comment on this, or on a feeling of fullness in the ear. A younger child might shake her head, pull on her ear, or give no sign at all.
OME is more likely if it is winter or if there is an obvious reason the Eustachian tube might be blocked (a current or recent cold, acute ear infection, or other upper respiratory infection, a change in elevation, teething, exposure to cigarette smoke, or drinking a bottle lying on the back).
OME itself is not contagious. Nevertheless, the upper respiratory infections that often set up OME can be quite contagious.
The same upper respiratory virus might spread throughout a group of children. They might all catch colds, but only those who are otitis-prone might end up with OME, and the ear fluid in the different children might all contain different bacteria!
The length of OME is quite variable. Almost half the children with OME will no longer have fluid within one month. About ninety percent will have the fluid resolve within three months.
A skilled observer can make the diagnosis by looking in the ears with an otoscope. To confirm the presence of OME, it is important to confirm the presence of fluid in the ear. This may be accomplished while looking in the ear with an otoscope by using a small rubber bulb to push air against the eardrum. Alternatively, this may be accomplished with automatic devices such as a tympanogram or an acoustic reflectometer.
In otherwise healthy children, OME is usually treated first with environmental control measures (breastfeeding, avoiding cigarette smoke, and reconsidering large group daycare). Sometimes a round of antibiotics is given, although this has not been proven to help.
Either way, these children should be followed until the fluid resolves.
A hearing test is indicated within 3 months if the fluid has not yet disappeared. A hearing loss greater than 20 decibels suggests that PE tubes could be beneficial. Children who have developmental disabilities or other limitations on language development may need a hearing test and specialist referral sooner.
Tube placement is recommended for most children, in any case, if fluid is still present after 4 to 6 months.
Laser myringotomy is a gentler, shorter duration option to PE tube placement.
Some children also need adenoidectomy for chronic OME.
The above time schedule may be accelerated for children with other conditions, such as repeated episodes of AOM, anatomic differences, immunity problems, or language delays.
Antibiotics, antihistamines, decongestants, and steroids have not been shown to be effective in treating OME, though they might be tried in some situations before tube placement surgery.
An important study was published in the Journal of the American Medical Association in 2006 showing that biofilms, collections of bacteria living within a sticky matrix, may play a role in chronic cases of otitis media, with or without effusions. It is still unclear, though, how to best treat these infections.
How can it be prevented? Preventing OME involves preventing acute ear infections and ensuring proper Eustachian tube function. Try:
Serous otitis media, secretory otitis media, silent otitis media, ear infection, silent ear infection.