What is sinusitis?

Causes and Symptoms

The sinuses are airspaces in the skull that exist in the forehead just above the eyes, on either side of the nose below the eyes, and in the area just above the nose and in between the eyes. The sinuses are lined with mucus and tiny hairs, called cilia, which trap inhaled particles and bacteria and move them back out through the nose. This action serves as a natural defense system to eliminate these potential irritants that are inhaled during normal breathing. The tracts through which the sinuses drain are relatively small and easily blocked by swelling of the area. This blockage can impair drainage and cause the buildup of normal sinus secretions.

The term “sinusitis” refers to irritation or swelling of the sinuses and their membranes. Typical symptoms may include a feeling of congestion or pressure in the nose or face and runny nose with secretions that may vary in color from clear to yellowish green to bloody. The facial pressure is often worse when bending forward.

Most often, sinusitis is precipitated by the common cold. Another frequent cause is allergies, with typical symptoms of sneezing, runny nose, and itchy, watery eyes. An allergic patient who is sensitive to a particular airborne substance (pollen, ragweed, dust, animal dander) has a particularly vigorous response when these particles land in the nose and enter the sinuses. An increased production of mucus and the body’s natural immune defenses combine to produce thick and copious nasal secretions that can fill the sinuses in an attempt to eliminate the offending agent.

Another factor that may predispose a patient to sinusitis is environmental exposure to smoke or air pollution, which are natural irritants to the sinuses. Problems that cause a blockage of the sinus drainage system by things such as nasal polyps, a deviated septum, or pregnancy (which leads to swelling of the nasal membranes as a result of hormonal changes) can interfere with mucus drainage from the sinuses. Finally, other genetic diseases such as cystic fibrosis or disorders of the immune system can predispose patients to sinusitis.

Although most cases of sinusitis are caused by viruses or allergies, these can often lead to infection by bacteria if they do not resolve promptly. Bacterial sinusitis requires treatment with antibiotics to avoid the rare but serious complications of infection of the orbit or infection of the brain and its surrounding tissues.

The distinction between bacterial and other causes of sinusitis is most accurately based on the patient’s symptoms and a physical examination. A patient is more likely to have bacterial sinusitis if two or three of the following symptoms are present for at least seven days: facial pressure, nasal congestion, discolored nasal mucus, decreased sense of smell, productive or “wet” cough, fever, tooth pain on the upper jaw, or bad breath.

Sinus X-rays, done frequently in the past, are not considered a reliable diagnostic test for sinusitis. Though sinus computed tomography (CT) scans allow intricate visualization of sinus anatomy, they do not reliably distinguish bacterial sinusitis from other forms and are useful only in cases of long-standing, refractory symptoms for which sinus surgery is being considered.

Treatment and Therapy

The initial treatment of sinusitis involves extra fluids, anti-inflammatory drugs such as ibuprofen, antihistamines, short-term use of nasal decongestant sprays (no longer than three days), and oral decongestants such as pseudoephedrine. Humidified air (for example, steam from a hot shower) and nasal irrigation with water or saline can offer short-term symptom relief.

If allergies are the cause of sinusitis, then oral or nasal allergy medications are appropriate. Examples are nonprescription antihistamines such as chlorpheniramine or diphenhydramine; they can cause drowsiness in some patients. Loratadine and other related, newer generation antihistamines are also available over the counter. They offer once-daily dosing and are significantly less sedating. Other nasal sprays such as topical steroids are available by prescription and offer significant relief.

If symptoms persist longer than seven to fourteen days, then antibiotic therapy may be necessary and evaluation by a health care provider is warranted. Many different types of antibiotics are effective for sinusitis, and prescription practices vary. Initial treatment is typically for two weeks.

Perspective and Prospects

Prior to the antibiotic era, the treatment of sinusitis involved drainage of the sinuses by extracting a tooth, puncturing the roof of the mouth, or entering the nose and creating a drainage tract through which secretions could be removed and the sinuses could be irrigated with fluid for cleansing. Given the invasiveness of these procedures, they have become uncommon with the development of effective antibiotic therapy.

The development of tiny, high-resolution cameras known as endoscopes in the 1950s created a revolution in the understanding of sinus disease. Direct visualization of the nasal passages and sinus drainage tracts allowed a better understanding of the sinus anatomy and thus led to the use of this equipment to facilitate surgical treatment.

Occasionally, patients with recurrent symptoms require surgical removal of infected sinus tissue and enlargement of the natural drainage tracts to minimize sinus obstruction. A specialist in otorhinolaryngology (or otolaryngology) can perform such surgery using an endoscope, without the need for general anesthesia. Patients do not typically require hospitalization, and complications are rare.

Bibliography

Beers, Mark H., et al., eds. The Merck Manual of Diagnosis and Therapy. 18th ed. Whitehouse Station, N.J.: Merck Research Laboratories, 2006.

Brook, Itzhak, ed. Sinusitis: From Microbiology to Management. New York: Taylor & Francis, 2006.

Carson-DeWitt, Rosalyn, and Brian Randall. "Sinusitis." Health Library, Sept. 30, 2012.

"The Difference between Sinusitis and a Cold." HealthyChildren.org. American Academy of Pediatrics, May 11, 2013.

Kennedy, David W., and Marilyn Olsen. Living with Chronic Sinusitis: A Patient’s Guide to Sinusitis, Nasal Allegies, Polyps, and Their Treatment Options. Long Island, N.Y.: Hatherleigh Press, 2007.

McCaffrey, Thomas. “Functional Endoscopic Sinus Surgery: An Overview.” Mayo Clinic Proceedings 68 (June, 1993): 571–577.

Mickelson, Samuel, and Michael Benninger. “The Nose and Paranasal Sinuses.” In Textbook of Primary Care Medicine, edited by John Noble. 3d ed. St. Louis, Mo.: Mosby, 2001.

"Sinusitis." MedlinePlus, Apr. 22, 2013.

"Sinusitis." National Institute of Allergy and Infectious Diseases, Jan. 2012.

Younis, Ramzi T., ed. Pediatric Sinusitis and Sinus Surgery. New York: Taylor & Francis, 2006.