Ear infections commonly occur in either the
middle ear or in the ear canal. When
the infection is in the middle ear it is called otitis media.
In the ear canal it is otitis externa.
The middle ear is located behind the eardrum and
contains a chain of tiny bones which connects the eardrum to the inner
ear. This space normally
contains air. The
presence of fluid can interfere with hearing.
Middle ear infections are very common in small
children. The peak
incidences are at ages 2 and 5 years.
The air containing middle ear space is ventilated by the
eustachian tube. The
eustachian tube connects the middle ear with the throat.
Its function is to ventilate the middles ear space and equalize
the pressure with the outside. When
this tube is obsructed, a vacuum develops in the middle ear.
The vacuum is then replaced by fluid.
This fluid frequently interferes with hearing.
The fluid also may become infected.
If the infection is not treated, the eardrum will usually
rupture, thus allowing the ear to drain.
Once the pus drains, the immune system will usually resolve the
complications such as facial paralysis, neck abscess or even brain
abscess may result from untreated infections.
Most middle ear infections are treated with
antibiotics. If the
infections are frequent or if fluid does not clear from the middle ear
after an infection and interferes with hearing, placement of tubes may
be considered. In
children this operation is done under a light general anesthesia.
In adults, it is frequently done as an office procedure under
local anesthesia. An
incision is made in the eardrum and a small tube is inserted into the
incision. Without the
tube, the eardrum would heal within a day or two.
Depending on the design of the tube, it may stay in several
months to several years before the eardrum heals underneath it and
extrudes the tube. The tube functions to bypass the eustachian tube
and ventilate the middle ear space preventing the accumulation of
fluid and the ensuing infection.
The tube mimics the body’s natural process of perforation of
the eardrum to ventilate the middle ear and drain the infection.
The ear canal which extends from the opening down
to the eardrum is occasionally infected.
This is usually associated with the prolonged presence of
moisture in the ear canal. It
is more common in diabetics or in immunocompromised patients.
Careful cleaning of the ear canal and antibiotic ear drops
usually suffice to clear the infection.