Please note that the following is a general guideline only.
What is the Middle Ear?
The outer ear is the ear canal which ends at the eardrum or the tympanic membrane
Middle ear extends from the tympanic membrane up to the inner ear structures (in blue). The middle ear contains several vital structures, including the three vibrating ear bones. Middle ear connects to the back of the nose via a small tube called the eustachian tube. The middle ear contains air under normal circumstances, which allows the drum and the bones to vibrate maximally for the sound to be amplified and transmitted to the inner ear.
Definitions
Acute otitis media (AOM) is defined as acute inflammation of the middle ear. Otitismedia with effusion (OME) is defined as middle ear fluid without signs or symptoms of an acute infection. Recurrent "AOM" is defined as 4 or more episodes in one year or three or more episodes in one 6 month period
How does one get a middle ear infection?
A common cold can cause swelling and narrowing of the eustachian tube. Blockage of the tube prevents air entry from the back of the nose into the middle ear (middle ear gets blocked off). The high blood circulation absorbs the air in the middle ear leading to negative pressure. This increase in negative middle ear pressure and decreased clearance eventually leads to swelling, damage and ooze of fluid from the surrounding structures. This fluid ends up with lots of bacteria.
Bacteria also may enter from the back of the nose, along the eustachian tube when open.
Colds can cause direct swelling of the middle leading to secondary bacterial infections.
Who is most affected?
Sex: Males>Females (some studies show no difference)
age: 6-11 months declines around 18-20 months
70% experience one or more attacks before two years of age
Race: higher incidence in indigenous (95% of Aboriginal children by two months)
Familial-higher predisposition
peaks in winter months which correspond to the peak in respiratory infections
Why are children most affected?
Due immature immune response. As a result, children who attend day care are most prone, especially before the age of 2 years. Smoking in households also increases the likelihood of ear infections.
Children's eustachian tubes are shorter and has less of an angel These structural differences make them more prone to bacteria travelling from the back of the nose.
Due to adenoids. Adenoids are lymphatic structures at the back of the nose. These, along with tonsils, play a part in immune development in infants. They do so by sending immune signals to build up immune function when crawlers introduce bacteria by putting things in their mouths. Adenoids themselves can get chronically infected, leading to smelly nasal discharge. These children are more prone to getting ear infections, as explained above.
Note: eustachian tubes open at the BACK of the nose
What are the consequences of ear infections and middle ear fluid?
1) Most kids develop no severe illnesses however the ongoing ear infections and fluid may lead to irritability, ongoing fevers and some delay in speech especially during their early years
2) Chronic recurrent ear disease may lead to thinning of the eardrum, ear skin entering the middle ear leading a condition called cholesteatoma. This is a rare but a significant complication which may take may years to develop and even present during adulthood.
3) perforated eardrum: ear infections may lead to holes in the ear drum
4) Acute complications may occur during these ear infections. These are much less common due to the introduction of antibiotics. These complications include mastoiditis: a form of bone infection, very rare extension of the infection to surrounding structures, including the brain and meningitis.
Bulging TM, loss of landmarks
Note the subperiosteal abscess, pain is over the high mastoid-the antrum
What do grommets do?
Grommets are little pipes placed on the ear drums after making a small incision These help drain infected fluid out, allow air in, and help treat any future infections with certain ear drops.
Who will benefit from surgery?
Indications for the grommets are
Recurrent infections more than 3 in three months or 4 or more in 1 year
Fluid behind the eardrum (with so symptoms of infections) for over 3 months
Failure of medical therapy and significant symptoms
Any of the complications above
Immunocompromised patients after failure of medical therapy with 48-72 hours
Adenoidectomy
Recommended removal (irrespective of size) during placement of the second set of tympanostomy tubes.
Also recommended if there are nasal symptoms (mouth breathing, nasal discharge)
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