The sinuses are cavities, or air-filled pockets, that are near the nasal passage. There are four different types of sinuses:

• ethmoid sinus - located between the eyes, around the area of the bridge of the nose. This sinus is present at birth, and continues to grow.
  
  
• maxillary sinus - located below the eyes, around the area of the cheeks. This sinus is also present at birth, and continues to grow.
  
  
• frontal sinus - located over the eyes, in the area of the forehead. This sinus does not develop until around seven years of age.
  
  
• sphenoid sinus - located behind the eyes, behind the nose. This sinus does not develop until adolescence.

The inside of the sinuses is similar to the inside of the nose.

Sinusitis is an infection of the sinuses surrounding the nose. These infections usually occur after a cold or after an allergic inflammation. There are four types of sinusitis:

• acute - symptoms of this type of infection last less than four weeks and get better with the appropriate treatment.
  
• subacute - this type of infection does not get better with treatment initially, and symptoms last four to eight weeks.
  
• chronic - this type of infection happens with repeated acute infections or with previous infections that were inadequately treated. These symptoms last eight weeks or longer.
  
• recurrent - three or more episodes of acute sinusitis a year.

Sometimes, a sinus infection happens after an upper respiratory infection (URI) or common cold. The URI causes inflammation of the nasal passages that can lead to obstruction of the opening of the paranasal sinuses, which can lead to infection in the sinuses. Allergic disease can also lead to sinusitis because of the swelling of the nasal tissue and increased production of mucus. There are other possible conditions that can block the normal flow of secretions out of the sinuses and can lead to sinusitis. These may include:

• abnormalities in the structure of the nose
• enlarged adenoids
• infections from a tooth
• trauma to the nose
• foreign objects that are stuck in the nose
• gastroesophageal reflux disease (GERD)
• secondhand smoke

After the blockage of the flow of secretions from the sinuses, bacteria will sometimes begin to grow. This leads to a sinus infection, or sinusitis. The most common bacteria that cause sinusitis are:

• Streptococcus pneumonia
• Haemophilus influenzae
• Moraxella catarrhalis

The symptoms of sinusitis vary for each person, and depend greatly on the age of the individual. The following are the most common symptoms of sinusitis. However, each individual may experience symptoms differently. Symptoms may include:

• runny nose that lasts longer than seven to 10 days. The discharge is usually thick green or yellow, but can also be clear.
  
  
• bad breath
  
  
• nighttime cough
  
  
• occasional daytime cough
  
  
• swelling around the eyes
  
  
• children usually do not complain of headaches if less than 5 years of age

older children and adults:

• runny nose or cold symptoms that last longer than seven to 10 days
• complaints of drip in the throat from the nose
• headaches
• facial discomfort
• bad breath
• cough
• fever
• sore throat
• swelling around the eye, worse in the morning

The symptoms of sinusitis may resemble other conditions or medical problems. Always consult a physician for diagnosis.

Usually, your physician can diagnosis sinusitis based on your symptoms and physical examination. In some situations, additional tests may be performed to confirm the diagnosis. These may include:

• cultures from the nose
  
  
• sinus x-rays - diagnostic test which uses invisible electromagnetic energy beams to produce images of internal tissues, bones, and organs onto film. (X-rays are not typically used, but may help assist in the diagnosis.)
  
  
• computed tomography (CT or CAT scan) - a diagnostic imaging procedure that uses a combination of x-rays and computer technology to produce cross-sectional images (often called slices), both horizontally and vertically, of the body. A CT scan shows detailed images of any part of the body, including the bones, muscles, fat, and organs. CT scans are more detailed than general x-rays.
  
  
• cultures from the sinus fluid
  
  
Treatment for sinusitis:

Specific treatment for sinusitis will be determined by your physician based on:

• your age, health, and medical history
• extent of the disease
• your tolerance for specific medications, procedures, or therapies
• expectations for the course of the disease
• your opinion or preference.
  
  
  Treatment of sinusitis may include the following:
  
• acetaminophen for pain or discomfort
• nasal drops
• medications to treat GERD
• surgery.

Decongestants and antihistamines do not seem to help the symptoms of sinusitis.

Antibiotics may be withheld for 10 to 14 days, unless severe symptoms develop, such as fever, facial pain or tenderness, or swelling around the eye. Surgery should be considered only if other treatments have failed.

Referral to an allergist/immunologist is often needed, particularly for people with chronic or recurrent sinusitis and for patients who have had sinus surgery, but who still experience sinusitis.