health

Infection of the outer ear, or otitis externa, is a skin infection caused by
bacteria or fungi that get into the skin of the ear canal through a scratch
or other small break in the skin. The skin lining the ear canal is very thin
and easily damaged. If a person goes swimming, takes a shower, or is
exposed to hot, humid weather, bacteria or fungi in the ear canal can
rapidly multiply and cause an inflammation of the skin. Because the skin
of the ear canal is closely attached to the underlying bone, the inflammation
can cause severe pain and swelling that may be sudden. The swelling
of the skin of the canal may lead to temporary hearing loss.
Infection of the middle ear, or otitismedia, is often a complication of the
common cold. It begins when cold viruses (or sometimes bacteria) enter the
Eustachian tube from the upper throat and produce inflammation and swelling
in the tube. Fluid builds up behind the eardrum when the Eustachian
tubes are blocked by swelling; this is called an effusion. The Eustachian tubes
can also be blocked by swollen adenoids, pieces of tissue that are part of the
immune system and lie at the very back of the nasal passages. If the adenoids
become infected, they can swell and block the Eustachian tubes.
Doctors usually distinguish between otitis media with effusion
(OME) and acute otitis media. In OME, the fluid that builds up behind
the eardrum is not itself infected; in acute otitis media, the collection of
fluid itself has become infected by bacteria. The difference is important
because it affects the treatment of the earache.