Sinusitis; chronic

Alternative names:

chronic sinus infection; chronic sinusitis

Definition:

A prolonged or recurrent infection and/or inflammation of the sinuses of the head.

Causes, incidence, and risk factors:

The sinuses are openings in the bones around the nose. There are 4 pairs of sinuses connected to the nasal cavity by small openings. Normally air passes in and out of the sinuses, and mucus and fluid drain from the sinuses into the nose.

Chronic sinusitis is much less common than acute sinusitis. It affects approximately 1 out of 1,000 people. Some people never get sinusitis, and others develop sinusitis frequently. When sinusitis recurs frequently, or lasts for a prolonged period of time, it is classified as chronic. Chronic sinusitis may have less severe symptoms than acute sinusitis, and it may therefore go untreated for long periods of time. This can cause damage and destruction to the tissues of the sinuses. Chronic sinusitis may flare up spontaneously or may follow respiratory infections such as colds.

Sinusitis occurs when there is an undrained collection of pus in one or more of the sinuses. Obstruction of the nose often causes sinusitis because fluid is unable to drain out of the sinuses. Allergic rhinitis or viral respiratory infections are common causes of acute sinusitis, but if they persist or recur they may lead to chronic sinusitis. A deviated nasal septum or other obstruction of the nose may also trap fluid in a sinus, causing chronic sinusitis. The fluid trapped in the sinus may then become infected with bacteria, viruses, or fungi. Dental infections such as tooth abscess may spread into the sinus and infect it directly.

Pain results from the inflammation itself or from pressure within the sinuses from accumulation of undrained fluid.