One of the most common conditions affecting children’s hearing is the presence of fluid in the middle ear. Normally, the middle ear is filled with air. The ventilating areas of the middle ear are connected with the back of the nose through the narrow auditory tube. The role of auditory tube is twofold:
- Carries air into the middle ear. This is necessary because the oxygen from the middle ear is absorbed into the blood through the epithelium of the middle ear. This would cause a decrease in pressure of the middle ear, which would make the tympanic membrane to bend inwards and thus disturb the hearing.
- Allowing the mucus produced naturally in the middle ear to escape to the nose so as to prevent accumulation.
After cold attacks, many people suffer from temporary weakness of the auditory tube to remove the mucus produced by the epithelium of the middle ear in response to viral infection. The result of this situation is a clogged ear and sometimes painful, with hearing loss and often the feeling that the patient can hear their own voice (autophonia). This condition is called acute otitis media and middle secretory usually improves within a few weeks without treatment.
In patients with frequent attacks or who have colds or allergies or who are sensitive to environmental contaminants like cigarette smoke, there may be a continuous production of mucus. If this fails to go away, the system of the middle ear is blocked by the mucus that is trapped in it. In trying to deal with this is like trying to pull content from a canister that has a very narrow opening. When the liquid stays there for 3 months or longer, the situation is called “sticky ear” – in other words, it is an chronic middle secretory otitis. This situation is also called middle otitis with effusion (especially in America) or in some cases, middle ear effusion. The above situation affects boys more than girls and is worse in winter than in summer. It can occur throughout childhood, but the incidence appears to form two peaks at 2 and 5 years of age, though the reasons for this are unclear.
The concentration of fluid in the middle ear causes a moderate hearing loss that is rarely worse than a hearing level of 45db. However, this can cause difficulty in learning to speaking when the state begins when the child is too young or to lead to inadequate development of skills in speech and vocabulary when the whole situation starts later.
Changes in behavior may occur and children may show a loss of attention, be feisty and aggressive, distant or introverted. They may even create imaginary friends. Installed chronic middle secretory otitis (CMSO) is rarely painful, but the discharge can become infected and then severe pain and fever may develop until the tympanic membrane is ruptured, when the mucinous, organized purulent exudate comes out (acute middle suppurative otitis).
Most children with established CMSO eventually recover without treatment, with the number of patients reduced by half every 3-4 months passed. However, all children do not recover automatically and there is a small group, about 5% of those starting with CMSO that continue to have problems with changes in the tympanic membrane, which can lead to severe disease (see tympanic membrane perforation and cholesteatoma).
Treatment of CMSO is difficult and in some cases is subject to controversy. Since most children recover without any treatment, some doctors recommend that to administer hearing aids to children and to treat occuring infections is enough. Although this approach can be effective for many children, there is a small group of children that will suffer permanent and irreversible damage to the tympanic membrane and middle ear if this policy of waiting is applied.
Clinical trials with administration of medications showed that in some allergic children intranasal steroids, administered either in the form of drops or sprays, helped to reverse the situation, but this treatment is not always effective.
The surgery involves the ventilating of the middle ear through a small ventilation tube with a diameter of about 1.5 mm. The cannula is inserted through a small incision made in the tympanic membrane (myringotomi) and allows air into the cavity of the middle ear, so the mucus can be sewer through the auditory tube. Ventilation seems to also help the epithelium of the middle ear to return to normal. In some cases, the introduction of the cannula is followed by removal of adenoids, because in 25% of children it helps to accelerate the physical solution of the situation.
For children with settled CMSO, the only treatment that restores hearing immediately is to introduce an operating cannula. There is insufficient evidence that a tube with a hole in the tympanic membrane makes the child more susceptible to infections of the middle ear after swimming. Most ENT surgeons advise parents to be careful when they bathe their children, because the soapy water has a low surface tension, which makes the water “thinner” and so it is easier for the dirty, soapy water to reach the middle ear and create problems. There are no restrictions on airline flights for children with tube and in fact a fully ventilated middle ear cavity makes the flight easier.
The tympanic membrane is a vibrant, growing part of the body and gradually moves the cannula and ultimately rejects it in the ear canal after 6 to 9 months. Some tubes come out faster and some take longer. The presence of a cannula in the tympanic membrane has minor side effects. In some children when the cannula is absorbed remains a small hole that cannot be healed. In the early stages this is not so bad, because the hole acts as a drain. In time, however, and when the child has outgrown the phase of CMSO, the hole may be a problem and will need to be repaired, if it continues to cause infections when water enters the ear.
The tympanic membrane can also be stretched slightly from the stay of the tube and reacts with the creation of limestone deposits in the stretched areas. These deposits are characterized as sclerosis of the tympanic membrane and, except in cases that are particularly pronounced (which is a rare event), have no effect on hearing or the ability to cope with changes in pressure.
In some cases CMSO may recur after removal of the tube, so you may need to install a new pair of tubes if hearing has been affected or if the tympanic membrane has undergone such changes that can lead to long-term problems. A small group of children need the repeated installment of a ventilation tube and eventually a decision will have to be made for a more permanent type of tube. This is not needed very often, but when the tympanic membrane is thinner and shows retraction or sticks on the anvil and stirrup, this therapeutic tactic helps prevent downtime in the tympanic membrane and in some cases can reverse the changes that have occurred.