Middle ear infection
 
Introduction
 
Ear infections can affect any one, though children are particularly vulnerable to them. But there are different types, and the possible treatment options will depend on what type it is, and what might have caused it.

The medical term for a middle ear infection is otitis media. There are three main types:
  • acute otitis media
  • chronic otitis media
  • 'glue ear' (secretory otitis media,also known otitis media with effusion)

The outer ear includes the parts of the ear that can be seen on the side of the head, as well as the canal that leads into the head.

The middle ear contains three small bones that help sounds reach the eardrum. A narrow tube (called the Eustachian tube) connects the middle ear to the throat, and regulates the pressure in the ear.

Otitis media affects the middle ear. It is very common in children under the age of eight, but you can get it at any age, and it can affect one or both ears. You are more likely to get otitis media if it someone in your family has had it, or if you live or work with people who smoke.
 
Causes
 
Acute otitis media
This type of infection is often caused by bacteria associated with a cold or sore throat, which can travel up the Eustachian tube, causing infection. The infection can cause pus and bleeding, and the eardrum may burst as a result of the pressure. In most cases, a burst eardrum heals by itself.

Chronic otitis media
If the eardrum does not heal completely, or if it has been punctured by a blow to the head, the ear becomes vulnerable to chronic otitis media. This type is not as painful as the acute type, but it can last for longer and the infection can occur over and over again. Chronic otitis media can also be caused by a condition called cholesteatoma, which causes an over-production of tissue in the middle ear.

Glue ear
This can develop if the Eustachian tube gets blocked. If this happens, the pressure inside the ear cannot be regulated. A sticky fluid builds up inside the middle ear and affects hearing.

Blockage of the Eustachian tube may be caused by an infection, an allergy, or by enlarged adenoids (cells at the back of the throat which help fight infections).

Children are particularly vulnerable to glue ear because they are less able than adults to fight off infections, and also because their Eustachian tubes are shorter, lie in a more horizontal position, and are more easily blocked. Children who get allergies and hay fever are more susceptible, too.
 
Symptoms
 
Acute otitis media
Symptoms of acute otitis media include:
  • severe earache
  • a feeling of 'fullness' in the ear
  • deafness
  • ringing in the ear
  • fever
  • a discharge of blood and pus if the ear drum ruptures
  • feeling generally unwell, with nausea, vomiting or diahorrea
  • children tugging at the ear or having trouble swallowing their food


Chronic otitis media
The symptoms of chronic otitis media are much less severe than with acute otitis media. It is usually painless, but there is likely to be a discharge of thick, smelly pus, and hearing may be affected.

Glue ear
There are no obvious signs of glue ear. Children sometimes complain that their ear feels 'plugged up' but the main symptom is deafness, which, in small children, is often mistaken for lack of attention.
 
Diagnosis
 
To diagnose otitis media, the doctor may:
  • look into the ears with an instrument called an otoscope
  • take a sample of any discharge for laboratory analysis
  • take a sample of blood for testing to confirm the presence of infection
  • carry out some simple hearing tests
  • request head X-rays or a CT scan to discover whether the infection has spread from the middle ear
 
Treatment
 
Left untreated, acute and chronic otitis media can lead to deafness or other serious complications. Glue ear rarely causes long-term physical damage, but the temporary deafness can affect a child's educational and social development. For these reasons, it's important to see a doctor if you think your child has otitis media.

Acute otitis media is often given a chance to clear up on its own. If this does not happen, it may be treated with antibiotics. Sometimes, nasal drops or sprays are prescribed to help unblock the Eustachian tube. Eardrops or tablets may be prescribed for the pain.

If the eardrum is likely to burst, a specialist in ear, nose and throat problems may perform a procedure called a myringotomy. This involves making a tiny hole in the eardrum (under general anaesthetic) so the fluid can drain out. The eardrum should heal about a week after the infection has cleared.

Chronic otitis media may be treated with antibiotics to clear the infection. However, surgery provides a more permanent solution. An operation called a tympanoplasty can repair the perforated eardrum, as well as any damage done to the bones in the middle ear. Alternatively, if the condition is caused by cholesteatoma, the excess tissue can be surgically removed.

Glue ear may clear up without treatment, but may also be treated with antibiotics. When hearing loss is involved, some doctors recommend a tympanostomy - an operation in which a tiny hole is made in the eardrum and a tube called a grommet is inserted. This allows lets the ear drain continually, and usually restores hearing.

If a child does have a grommet, an earplug must be used when swimming to prevent bacteria entering the ear. He or she should also be examined regularly by a doctor. The grommet usually falls out after eight months to a year, and the hole usually closes within another eight to nine months.

Not all doctors recommend grommets. The risks include permanent damage to the middle ear or eardrum.
 
Preventing otitis media
 
Good management of colds, flu and sore throats, and of hay fever and other allergies may help. There is some evidence that breastfeeding babies during their first three months, and that feeding babies in an upright position, decreases the risk of glue ear. Passive smoking and using a dummy have been shown to increase the risk.
 
Further information
 
Royal National Institute for Deaf People
http://rnid.org.uk/html/info_factsheets.htm

American Academy of Otolaryngology - Head and Neck Surgery
http://www.entnet.org/healthinfo/ears/earache.cfm

National Institute on Deafness and Other Communication Disorders
http://www.nidcd.nih.gov/health/pubs_hb/otitism.htm
 
Healthwise (Health Information Resource Centre)
Tel : (852) 2849 2400
Fax : (852) 2849 2900
Email : info@healthwise.org.hk
Homepage : http://www.healthwise.org.hk/

This leaflet is for information only. For a detailed opinion or personal advice, please consult with your own doctor
 
 
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