Sinusitis
Sinusitis is an infection or inflammation that occurs in one or more of the four sets of paranasal sinuses. Sinuses are hollow, air filled cavities inside the head around the nasal cavity area (Sinusitis, 1999). The sinuses all have openings into the nasal canal to allow for continuous air and mucous exchange and secretion. A common theory surrounding the need and purpose of sinuses is that they help to lighten the entire weight of the skull. Sinuses also function to help humidify air and capture inhaled or inspired dust particles (Lev, 1998).
The four sets of paranasal sinuses include:
Ethmoid Sinuses (green)
Frontal Sinuses (checkered)
Maxillary Sinuses (red)
Sphenoid Sinuses (yellow)

The ethmoid sinuses are located between the nose and eyes. The frontal sinuses are found in the forehead and eyebrow area. The maxillary sinuses are in the area of the cheekbones. And lastly, the sphenoid sinuses, which sit farthest back in the skull, are deep behind the nasal cavity (Sinusitis, 1999).
The two major classifications of sinusitis are chronic and acute cases.
Acute sinusitis is the abnormal secretion and production of mucous. This is similar to cystic fibrosis. On x-rays, acute sinusitis is suggested by air fluid levels in the sinuses. Patients with immunodeficiency diseases, such as HIV or AIDS, are more likely to acquire acute sinusitis (Lev, 1998).
Chronic sinusitis is a disease usually diagnosed after a patient has had
a sinus infection lasts longer than three weeks to three months. There
are variable sources of chronic sinusitis that include allergies, asthma,
nasal polyps, and damp weather. On x-rays, chronic sinusitis is seen as
nasal sinus wall thickenings and bony sclerosis. The general population
is more at risk to developing chronic sinusitis (Sinusitis, 1999).
Drainage problems and air pressure are not the only causes of sinusitis. Any injury or infection that causes swelling of the face and nose can end up affecting the sinuses. Processes that are involved with changing anything in the sinuses can lead to serious problems and infections such as sinusitis.
The four most common causes come from (1) Viral Infection
(2) Bacterial Infection
(3) Fungal Infection
(4) Allergic Responses
Viral infections of the sinuses would be from things such as colds or tooth infections. Streptococcus pneumoniae and Haemophilus Influenzae have also been found to lead to sinusitis (Sinusitis, 1999).
Bacterial infections are caused by bacterial growth in the upper respiratory tract. Bacteria get caught in obstructed and blocked sinuses and cause infection in mucousal linings (Sinusitis, 1999).
Fungal infections usually cause acute sinusitis. Fungi, such as Aspergillus, are found in immunodeficent people and a failure to respond to antibiotics can lead to spread of infection to the sinuses (Lev, 1998).
Allergic reactions are broken down into two categories. The first is labeled
Allergic Rhinitis. This tends to be from hay fever. The hay fever causes
an infection in the nasal passageway that leads to sinus infections and
eventually sinusitis. The second allergic response is called Vasomotor
Rhinitis. Cold air, humidity, alcohol, perfumes, environmental conditions,
and dust can lead to vasomotor rhinitis and can be followed by sinusitis.
Other general signs include the following:
* Headache
* Loss of smell
* Nasal Discharges
* Fatigue
* Nasal Congestion
* Pain
* Post Nasal Drip
* Pressure
* Runny Nose
* Fever
* Cough
* Sore Throat
* Facial Pain
* Loss of Sleep
* Difficulty Breathing Through the Nose
A doctor can look into the nose and will see reddening and swelling of
the mucous membranes if sinusitis is present. The discharge from the nose
may be green or yellow in color. And severe cases of sinusitis left untreated
can progress and cause severe brain infections (Sinusitis, 1999).
For more information please check out the following web sites:
References
Lev, M.H.,
Groblewski, J.C., Shortsleeve, C.M., and Curtin, H.D. (1998, January).
Imaging of the sinonasal cavities: inflammatory disease. Applied
Radiology , 185, 1-6. Retrieved on March 16, 2001 from
the World Wide Web: [online] Available:
http://www.appliedradiology.com/article/article.asp
Merck Manual of Medical Information (book). Home Ed. (1997). 1112-1113. New York: Merck & Co.,Inc.
Pal,
Shalmali. (2000, February). Lose dose CT touted for oft-needed
sinus imaging. AuntMinnie: Radiology Starts Here. 1-2.
Retrieved on March 16, 2001 from the World Wide Web: [online] Available:
http://www.auntminnie.com
Sinus Infections (sinusitis). (1999). 1-2. Retrieved
on March 14, 2001 from the World Wide Web: [online] Available:
http://www.entmanual.com
Sinusitis and Sinus Pain Relief- SinuCare. (2000). 1-2.
Retrieved on March 14, 2001 from the World Wide Web: [online] Available:
http://www.sinucare.com/sinuspain.html
WebMD. Sinusitis. (1999) 1-4. Retrieved on March
16, 2001 from the World Wide Web: [online] Available:
http://www.mywebmd.com/content/article1680.51929
Labeled
sinus diagram. Retrieved on March 14, 2001 from the World Wide Web: [online]
Available:
http://www.sinucare.com/sinuspain.html
Colored
sinus graphics. Retrieved on April 14, 2001 from the World Wide Web: [online]
Available:
http://www.sinuscarecenter.com