Glue ear is a common but poorly understood childhood condition where fluid builds up in the middle ear. The medical term for glue ear is otitis media with effusion.

The most common symptom of glue ear is some loss of hearing, which can range from slight to mild to moderate. The hearing loss of glue ear is similar to what you would experience if you put your fingers in your ears.

Glue ear is usually a self-limiting condition which means that it will get better by itself without the need for treatment.

The middle ear

The middle ear is directly behind the eardrum. It is made up of three tiny lever-like bones that carry sound vibrations from the eardrum to the inner ear.

In cases of glue ear, the build up of fluid prevents the three tiny bones in the ear - the stirrup (stapes), anvil (incus), and hammer (malleus) - from moving freely.

These three bones are responsible for transmitting sound vibrations to the inner ear. However, if they are unable to transmit the vibrations, sounds coming into the ear can become muffled.

How common is glue ear?

Glue ear is a common condition in young children, with cases being particularly widespread in children who are around two years of age. The number of cases of glue ear decreases in children who are over six years of age.

It is estimated that 90% of all children in England will have at least one episode of glue ear by the time that they are 10 years of age.

Cases of glue ear are more common during the winter months. Around 50 per cent of cases of glue ear develop after a previous ear infection (otitis media).

The exact cause (or causes) of glue ear are unknown. However, it is known that glue ear is not the result of water getting into the ear through activities such as swimming and showering, or due to a build up of ‘ear wax’.

Outlook

The outlook for children with glue ear is usually very good, with half of all cases being resolved within three months.

Treatment is usually only recommended when symptoms last longer than three months, and the degree of hearing loss is thought to be significant enough to potentially interfere with a child’s language and speech development. In these circumstances, glue ear can usually be treated using minor surgery.

The most common complication of glue ear is that the fluid in the ear becomes infected by bacteria (otitis media). Otitis media is usually a mild type of infection that will pass within 2-3 days.

The most common symptom of glue ear is some degree of hearing loss.

In children under the three years of age, two out of three cases of glue ear affect only one ear (unilateral), with one in three cases affecting both ears (bilateral). In children over the age of three, half of all cases of glue ear are unilateral, and the other half are bilateral.

The degree of hearing loss ranges from slight to mild to moderate.

Slight hearing loss

If your child has slight hearing loss, they may have difficulty understating people who are far away or speak quietly. They may also appear unusually tired or irritable because they have to make more of an effort to listen to things.

Mild hearing loss

If your child has mild hearing loss, it is likely that they will have considerable difficulty understanding people who are far away or speak quietly.

Your child may have problems picking out conversations in places where there is a lot of background noise. They may also easily ‘tune out’ of conversations when they are distracted. For example, if they are watching their favourite television show, it is likely that they will be unaware of many of the sounds around them.

Moderate hearing loss

If your child has moderate hearing loss, it is likely that they will only be able to understand face-to-face conversations that take place at a distance of between 1-1.5 meters (3.25 -5 feet).

They may also experience problems with communication, learning, and social skills. However, in most cases, these problems will resolve once their hearing is restored to normal.

Less common symptoms

Less common symptoms of glue ear include:

• episodes of mild ear pain,
• irritability,
• problems sleeping,
• balance problems,
• appearing unusually clumsy, and, in younger children,
• delayed speech and language development.

The exact cause (or causes) of glue ear are not known, although the condition seems to be due to a problem with part of the body called the Eustachian tube.

The Eustachian tube

The Eustachian tube is a thin tube that runs from your middle ear to the back of your nose.

The Eustachian tube has two main functions that are explained below.

• It ventilates your middle ear, helping to maintain a normal air pressure within the middle ear. Sudden changes in air pressure can be painful and, in some cases, can damage the ears. It is a change in air pressure that is responsible for the popping sensation that many people experience on an aeroplane.
• It helps to drain away mucus and other debris from the ear. The middle ear can often become clogged with mucus due to inflammation, infection or, in some cases, an allergic reaction.

In cases of glue ear, it seems that the Eustachian tube loses the ability to drain away the mucus. The mucus builds up inside the ear leading to glue ear. The reasons for this loss of function are still unclear, but some suggestions include:

• changes in air pressure inside the ear that lead to a blockage in the Eustachian tube,
• inflammation of the Eustachian tube due to infection, or irritants, such as cigarette smoke, which causes the tube to narrow,
• gastric fluids from the stomach that leak back up through the throat and into the Eustachian tube, and
• genetic mutations (altered genes) - some children may be born with certain genetic mutations that mean that their Eustachian tube does not develop properly.

Risk factors

While it is not known exactly what causes glue ear, a number of risk factors have been identified that have been linked to an increase risk of children developing the condition. These include:

• living in a house where the parents smoke,
  not being breastfed, and
• having a large number of brothers and sisters (this may be due to having an increased risk of developing an infection if there are several children in the house).

In diagnosing glue ear, your GP will ask you about your child’s symptoms and whether you have noticed any change in the pattern of their behaviour, such as changes in their speech, or their interaction with others.

A diagnosis of glue ear can usually be confirmed using an instrument called an otoscope. An otoscope is a small, hand-held device that has a magnifying glass and a light source at the end, and is used to study the inside of the ear.

There are certain signs that that can be detected using an otoscope that usually indicate the presence of fluid inside the middle ear. These include:

• the ear drum is pulled inwards,
• the ear drum is an unusual colour,
• the ear drum has a cloudy appearance, and
  bubbles and fluid are visible inside the ear.

Further testing

Further testing is usually only required if your child’s symptoms persist for more than three months. The tests will usually be carried out your local ear, nose and throat (ENT) department.

Two tests that may be carried out include:

• an audiogram - which is used to assess the extent of your child’s hearing loss, and
• tympanometry - which is used to assess how much fluid is present in the middle ear.

These tests are discussed in more detail below.

Audiogram

An audiogram hearing test is performed using a machine called an audiometer. The audiometer produces sounds of different loudness and frequency. Your child will listen to the sounds using headphones, and will be asked to indicate when they can hear a sound and when they cannot.

This test will not cause your child any discomfort, and most children tend to find it interesting. Your child's ability to hear the different sounds can be seen on a chart called an audiogram.

Tympanometry

Tympanometry is a test that measures how the ear drum reacts to changes in air pressure. A healthy ear drum should move easily if there is a change in air pressure. If your child’s ear drum moves sluggishly, or not at all, it usually suggests the presence of fluid.

During a tympanometry test, a probe will be place into your child’s ear. The probe changes the air pressure at regular intervals while at the same time transmitting a sound into the ear.

A measuring device is attached to the probe which records how the sound reflects back from the ear, and how changes in air pressure affect these measurements.

If less sound is reflected back when the air pressure inside the ear is high, it usually indicates that the ear drum is having problems moving due to fluid.
 

Watchful waiting

For the first three months after glue ear has been diagnosed, a policy of ‘watchful waiting’ will usually be recommended. This means that your child will receive no immediate treatment, but their condition will be actively monitored.

There are two main reasons for this:

• 50 per cent of cases of glue ear will resolve within three months (this figure rises to between 75-90 per cent in cases where glue ear is followed by an ear infection), and
• currently, there is no available medication that has proven effective in shortening the duration of symptoms.

A wide range of medications have been tested for treating the symptoms of glue ear including:

• antibiotics,
• antihistamines,
• decongestants, and
• steroid sprays.

Evidence suggests that all of the medications listed above either have very limited, or no, effectiveness in shortening the duration of symptoms.

Once three months has passed, your child will be tested again to see if their symptoms are still present.

Indications for treatment

If testing reveals that your child still has fluid in their ear(s), it does not necessarily mean that they will automatically benefit from treatment. This is because 90 per cent of all cases of glue ear resolve within a year.

Surgery is usually only recommended if your child:

• has moderate hearing loss that is affecting both ears, or
• has a pre-existing health condition which, in combination with glue ear, could significantly affect their development in terms of language, speech, and learning.

Examples of such a pre-existing health condition include:

• a pre-existing hearing impairment other than glue ear,
• a suspected, or diagnosed, speech and language disorder, such as verbal apraxia which is a condition where children have difficulties controlling the muscles needed for speech, 
• a development disorder such as autistic-spectrum disorder,
• a syndrome (a collection of related symptoms) that is known to cause delays in speech, language, and learning development, such as Down’s syndrome,
• blindness, or significant visual impairment, or
• a cleft palate - a birth defect that affects the roof of the mouth and is known to cause difficulties with speaking.

Some common types of treatment are explained below.

Grommet insertion

A grommet is a very small ventilation tube that is inserted into your child's ear through a small incision (cut) in their eardrum. A grommet will help to drain away fluid in the middle ear, and it will also help to maintain the air pressure in the middle ear cavity.

A grommet insertion is performed under general anaesthetic (where the patient is unconscious), and the procedure usually takes about 15 minutes. Your child should be allowed to go home the same day.

During the first few days after surgery, your child may find that noises sound much louder than they are used to. This is normal and should pass as your child gets used to having a normal level of hearing.

A grommet will help keep the eardrum open for several months. As the eardrum starts to heal, the grommet will slowly be pushed out of the eardrum and will eventually fall out. This process happens naturally and should not be painful.

Most grommets will fall out between 9-15 months after they have been inserted. About 30 per cent of children will need further grommets inserted in order to fully treat the condition.

Autoinflation

Autoinflation is a treatment method that involves your child blowing up a special balloon using their nose. It helps to open up the Eustachian tube, making it easier for the tube to drain fluid away from the middle ear.

Your child will need to do this on a regular basis until all the fluid has been drained away.
Autoinflation does not work for every child, and it can be a difficult procedure for young children to perform.

Adenoidectomy

An adenoidectomy is the surgical removal of the adenoids.

The adenoids are soft mounds of tissue that are located at the very back of the throat. They are part of the body’s immune system which helps fight infection. If your child’s adenoids are enlarged and swollen, they can sometimes block the Eustachian tube. Having them removed can help the Eustachian tube to function more effectively.

An adenoidectomy is usually only suitable for children who are over three years of age, and in cases where there is evidence that their adenoids are contributing towards symptoms.

The procedure will be performed under general anaesthetic, and your child will usually be allowed to go home the same day. An adenoidectomy is often performed at the same time as a grommet insertion.

Hearing aids

Hearing aids can be used as an alternative to surgery.

A hearing aid is an electronic device that consists of:

• a microphone,
• an amplifier,
• a loudspeaker, and
• a battery.

Modern hearing aids are very small and discreet and some can be worn inside the ear. The microphone picks up sound, which is made louder by the amplifier. Hearing aids are also fitted with devices that can distinguish between background noise, such as traffic, and foreground noise, such as conversation.

Speech and language development

Children with glue ear may experience some delay in their speech and language development, particularly if their loss of hearing is prolonged and occurs before three years of age. However, in most cases, the delay is only temporary and children will usually ‘catch up’ once their hearing returns to normal.

One study looked at how children with an early history of glue ear performed at school and could find no significant differences compared to other children of the same age.

Acute ear infection

An acute ear infection (otitis media) is a common complication of glue ear and develops when bacteria infect the fluid inside the middle ear.

Symptoms of otitis media in children include:

• ear pain,
• crying more than usual,
• problems sleeping,
• having a high temperature (fever) of 38C (100.4F) or above, and
• a discharge of fluid or pus from the ear.

About 80 per cent of cases of otitis media will pass within 2-3 days without the need for treatment. Antibiotics can be used if symptoms are particularly severe.

Tympanosclerosis

Tympanosclerosis is a term that describes the slight thickening of the eardrum tissue. It is a common complication in children with glue ear who were treated with grommets, and it occurs in an estimated 25 per cent of cases.

It is uncertain whether the thickening of the ear drum is due to the grommets, glue ear itself, or a combination of both of these factors.

A small amount of hearing loss is the most common symptom of tympanosclerosis. However, it is usually so mild that it is barely noticeable. In cases where hearing loss is more severe, surgery may be required to reconstruct the ear drum.

Perforation

If glue ear is complicated by infection, there is a small risk that pus can form inside the middle ear. The pus can put pressure on the ear causing a hole (perforation) to develop in the ear drum.

A perforated ear drum is an uncommon complication of glue ear, occurring in an estimated two per cent of cases.

Having a perforated ear drum can lead to some loss of hearing. In most cases, the ear drum will heal by itself within 6-8 weeks.

In the remaining cases, chemicals can be used to encourage the ear drum to heal, or it can be treated using minor surgery.

As the cause of glue ear is not fully understood, there is no known way of preventing the condition from occurring.

However, steps can be taken to reduce two of the known risk factors for children. These include:

• not bringing your child up in a smoky environment, and ensuring that they avoid close contact with smokers (passive smoking), and
• being breastfed as a baby.

Passive smoking

The reason why passive smoking increases the risks of developing glue ear is unclear. It may be that the smoke irritates the lining of the Eustachian tube, causing it to become inflamed.

Not smoking around your children also has many other important health benefits including:

• reducing the risk of developing asthma,
• reducing the risk of developing a chronic lung condition in adulthood, and
• reducing the risk of dying from sudden infant death syndrome (SIDS) which is also known as cot death.

If you are a smoker, you should always make sure that you smoke outside your house. Smoking in another room can still present a threat to your children’s health because the smoke can easily travel from one room to another, and the toxic chemicals in tobacco smoke can stay in the air for several hours.

Breastfeeding

As with passive smoking, exactly why breastfeeding reduces the risk of glue ear is uncertain. One theory is that breast milk contains proteins that help to reduce inflammation inside the Eustachian tube.