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Fact File
Glue ear
Glue ear is a build-up of gunk inside the middle ear cavity. It's the most likely reason that children under five will end up on the operating table, often unnecessarily.
Published 27/03/2003
[Image source: iStockphoto]
Background
Glue ear is a build-up of gunk inside the middle ear cavity. It sounds innocuous, but it's the most likely reason that children under five will end up on the operating table, often unnecessarily.
The surgery involves inserting grommets, or ventilation tubes, in the eardrum. These help dry up the fluid – but for most children it's not the fluid itself that's the problem. Rather, it's the muffled hearing that can result, as the fluid impairs the vibration of the small bones in the ear cavity that transmit sound.
Surgery isn't usually necessary, however. Most cases of glue ear will clear up by themselves, and some researchers believe that surgeons tend to be too hasty.
What is glue ear?
Medically known as otitis media with effusion, glue ear is different from acute otitis media, which is a short-term ear infection.
Both involve inflammation of the middle ear ('otitis media'), both involve a build-up of fluid, and both are common in babies and young children. Four out of five children will get at an ear infection at some stage.
But unlike glue ear, acute otitis media is accompanied by short-lived pain and fever. Acute otitis media can sometimes turn into glue ear, or the reverse can happen: glue ear can lead to an acute infection.
Infections (such as a cold or flu) are thought to contribute to glue ear, but sometimes glue ear just happens for no apparent reason. Glue ear may also result from an allergy, though doctors disagree on this.
The reason young children are most vulnerable to glue ear is because their Eustachian tubes (the passage between the middle ear and throat) are short and narrow, so can get blocked easily. Fluid secreted in the middle ear is trapped, rather than simply draining into the throat.
Glue ear is a build-up of fluid in the middle ear.Although all children are susceptible to ear infection, children exposed to lots of other children in group day care or at home are at significantly more risk (since exposure to other children increases the chances of catching a cold). Aboriginal children and children from lower socio-economic groups are also at high risk.
There are other risk factors (like exposure to tobacco smoke, bottle feeding, and being a boy), but they seem relatively less important.
Symptoms
Glue ear is not obvious from the outside and it usually goes undetected. Often the first thing a parent notices is hearing loss: the child may not respond to quiet sounds, does not turn around when you walk up behind them, sits close to the television, and seems inattentive.
Whether or not fluid is present can be confirmed by an ear examination.
Diagnosis
A lighted instrument called an otoscope is used to look for changes in the external ear canal and eardrum. A version of this instrument called a pneumatic otoscope also enables the doctor to blow a puff of air against the eardrum to see how well it moves. This makes it much more accurate in detecting glue ear, but many Australian doctors aren't trained to use it.
Other instruments and tests, such as tympanometry, may also be used by audiologists to diagnose ear problems. Tympanometry measures pressure differences between the middle ear and outer ear by measuring how easily the eardrum vibrates back and forth.
To measure whether the fluid is causing hearing loss, a separate hearing test is necessary.
Treatment
Most cases of glue ear will clear up by themselves. But for many years, parents and professionals have worried that hearing loss may interrupt a child's speech, language development, and behaviour. Now it seems that glue ear by itself may be much less damaging than previously thought.
The amount of hearing loss suffered varies between zero and 60 decibels, with an average of 25 decibels. A 25 decibel hearing loss softens normal speech, so it sounds more like a whisper.
Treatment options include:
- Watchful waiting. About 30 per cent of cases will clear in several weeks without treatment, rising to about 90 per cent of cases in several months.
- Antibiotics. Before opting for surgery, a course of antibiotics may be tried. This will only be helpful if there is a bacterial infection present – studies suggest antibiotics may help only in about one in four cases.If antibiotics are used, it's very important that all medicine be given to the child as prescribed rather than stopping partway through, even if symptoms have disappeared. Usually, only one course would be prescribed. Antibiotics may have side effects such as nausea, diarrhoea, and rashes. Also, if they are over-used, disease bacteria can become resistant to them, making them less effective generally.
- Auto-inflation. Another way to get air into the middle ear cavity is via the nose and Eustachian tube. This may be done by holding your nose and 'popping' your ears, or using a balloon-like device which the child blows up with their nose (yes, their nose). The few studies that have been done on auto-inflation have had mixed results: on the whole, it may help, and probably doesn't do any harm.
- Surgery. If the child's hearing loss is 30 decibels or more in both ears, and continues for more than three months, surgery may be recommended. It involves making a small cut in the eardrum (called 'myringotomy' or 'tympanostomy') and inserting tiny circular tubes (called 'grommets', 'ventilation tubes' or 'tympanostomy tubes') into the cut to hold it open and allow air to pass through. Surgery involves the risk associated with an anaesthetic, and there are also potential complications. The grommets are supposed to come out by themselves after six to 12 months, but they may fall out earlier or later. Sometimes they may cause an infection or a permanent hole in the eardrum.
There is no doubt that grommets effectively relieve hearing loss over the first six months or so, but they may give little benefit in the long term because most children will 'catch up' with speech and language development. Only a few well-designed studies have been done, and most suggest that grommets make little or no difference to children's speech and development over time. More research is necessary to decide for sure. However, many parents report an immediate improvement which they think is worthwhile. - Allergy treatment. Studies are conflicting about whether allergy treatment for glue ear is effective. There have been some good results, especially in children who have had several sets of grommets and still have fluid in the ear. In such cases, the inflammation may be caused by an allergy rather than by an infection, and so allergy testing and treatment (such as desensitisation treatment, food elimination diets, or house dust mite control) may help.
- Speech therapy. If you think your child has speech, language or development problems, check these out while you're checking out the ears – don't wait until after the grommets! Language problems are common in preschool children with and without glue ear, and should be assessed in their own right – regardless of the presence of middle ear fluid.