Sinusitis
Alternative names:
acute sinusitis; sinus infection; sinusitis - acute
Definition:
A disorder of the sinuses surrounding the nose, in which
one or more of these sinuses are inflamed. Acute sinusitis
typically lasts 3 to 8 weeks, whereas chronic sinusitis lasts
longer.
Causes, incidence, and risk factors:
There are 4 pairs of sinuses connected to the nasal cavity
by small openings called ostia. Nasal sinuses are small mucous-lined
pockets within the facial bones surrounding the nose. Normally,
these sinuses make mucus that drains from the sinuses into
the nose while air passes freely in and out. Sinusitis (inflammation
of the sinuses) occurs when at least one of three conditions
is manifest: (1) The small openings (ostia) from the sinuses
to the nose are blocked; (2) small hairs (cilia) in the sinuses
that help move the normally produced mucous out are not working;
and (3) too much mucous is produced, often simply a result
of inflammation. Any combination of these may cause sinusitis.
Sinusitis affects approximately 3 out of 1,000 people, and
develops in approximately 31 million Americans alone each
year. Sinusitis typically follows a upper respiratory infection
or allergic reaction, which can cause inflammation and swelling
that close off the sinus ostia. This encourages mucous accumulation
in the sinuses, and makes the sinus a great place for bacteria
and fungus to live and grow rapidly. Individuals with weakened
immune systems are at greatest risk since their risk of any
infection is high.
While the most frequent cause of sinusitis is upper respiratory
tract infections (common colds) or allergic rhinitis, other
risk factors include: history of asthma overuse of nasal decongestants;
deviated nasal septum; nasal bone spurs; nasal or facial tumors;
nasal polyps; foreign bodies; frequent swimming and/or diving;
and dental work. Typically, these all cause blockages of the
sinus ostia, and are the result of problems that affect the
nasal area only. Diseases that are considered systemic (affecting
the whole body) typically render individuals immunosuppressed
and, in turn, at increased risk for infection. These include
HIV infection, cancer, and patients on immunosuppression or
receiving chemotherapy. People with one of a number of diseases
that prevent the cilia (hair that helps move mucus out of
the sinuses) from working are also at risk. These diseases
include Kartagener's syndrome, cystic fibrosis, and immotile
cilia syndrome.
Remember, these diseases predispose individuals to develop
sinusitis because they make the sinuses a better place for
infectious organisms, especially bacteria, to grow. Not all
individuals with the above conditions develop sinusitis, but
they are at risk.
Update Date: 04/01/00
Update By: Luis A. Diaz, Jr. M.D., Johns Hopkins Medical Institute, VeriMed
Health Network
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