By Barry Rosenblum, MD

Patients with congested nasal passages often assume they have a sinus infection or “sinusitis.” Inflamed nasal passages actually can be caused by allergies or viral colds. Physicians, therefore, generally limit the definition of sinusitis to bacterial infection of the sinuses.

There are four pairs of sinuses. These include the frontal sinuses above the eyes, the maxillary sinuses under the eyes and behind the cheeks, the group of small ethmoid sinuses between the eyes, and a pair of sinuses deep behind the nose at the base of the brain known as the sphenoid sinuses.

The mucus membrane lining of the sinuses is a very specialized layer of cells characterized by microscopic fingers known as cilia. The cilia trap bacteria, viruses and other particles and propel them in a mucus blanket from the sinuses into the nose for clearance. The average person secretes 1 to 1 ½ liters of nasal and sinus secretions per day. Secretions in excess of this amount should be evaluated.

Many people believe that any sinus drainage is abnormal. This, of course, is not true and we rely on a steady flow of mucus from our nose and sinuses to keep these structures clean and relatively sterile.

Sinuses drain into the nose and circulate air from the nose into the sinuses through a series of holes known as ostia. Anything which obstructs this airflow, including mucus membranes, swelling, bone derangements from injury or inherited conditions or polyps will result in impairment of ventilation and drainage and, ultimately, sinusitis.

The symptoms of sinusitis differ between the acute and chronic phases. Acute sinusitis — usually the first four weeks — is characterized by nasal discharge, headache, facial pain, fever, tooth pain, decreased sense of smell and cough.

Chronic sinusitis — when the condition persists for 12 or more weeks — is less localized and presents with a dull headache, chronic nasal congestion, thick posterior nasal drainage and often eustachian tube dysfunction with ear blockage.

The treatment of sinusitis typically includes antibiotics prescribed for 10 to 21 days, decongestants and mucolytics, topical vasoconstrictors such as Afrin or Neo-Synephrine and, in selected cases, systemic steroids.

Unfortunately, bacteria are becoming increasingly resistant to antibiotics and stronger antibiotics are required more often than in the past.

In cases of recurrent sinusitis, the physician looks for underlying causes, like septal deviation, allergies, nasal polyps, an immunocompromised state, tumor and foreign body (particularly in children). This search will include very likely an endoscopic exam and imaging studies, often in the form of a CT scan.

An uncommon but well-recognized variant of chronic sinusitis includes fungal sinusitis, caused not by bacteria but by fungi. This form of sinusitis is more difficult to treat and usually requires surgery.

Over the years, the medical community has become aware that the sinuses are not an isolated organ system, but one end of the respiratory system. Sinusitis, therefore, can impact our pulmonary health and aggravate asthma and other lung conditions. Therefore, treatment of sinusitis may be necessary before lung conditions can be brought under control.