Complications

Bacterial sinusitis is nearly always harmless (although uncomfortable and sometimes even very painful). If an episode becomes severe, antibiotics generally eliminate further problems. In rare cases, however, sinusitis can be very serious.

Osteomyelitis. Adolescent males with acute frontal sinusitis are at particular risk for severe problems. One important complication is infection of the bones (osteomyelitis) of the forehead. In such cases, the patient usually experiences headache, fever, and a soft swelling over the bone known as Pott's puffy tumor.

Infection of the Eye Socket. Infection of the eye socket, or orbital infection, which causes swelling and subsequent drooping of the eyelid, is a rare but serious complication of ethmoid sinusitis. In these cases, the patient loses movement in the eye, and pressure on the optic nerve can lead to vision loss, which is sometimes permanent. Fever and severe illness are usually present.

Blood Clot. Another danger, although rare, from ethmoid or frontal sinusitis are blood clots. If a blood clot forms in the sinus area around the front and top of the face, symptoms are similar to orbital infection. In addition, the pupil may be fixed and dilated. Although symptoms usually begin on one side of the head, the process usually spreads to both sides.

Ischemic Stroke. One small and preliminary study found a link between ischemic stroke and sinusitis. More research is needed to determine if this possibility is valid.

Widespread Infection. The most dangerous complication of sinusitis, particularly frontal and sphenoid sinusitis, is the spread of infection by anaerobic bacteria to the brain, either through the bones or blood vessels. Abscesses, meningitis, and other life-threatening conditions may result. In such cases, the patient may experience mild personality changes, headache, altered consciousness, visual problems, and, finally, seizures, coma, and death.

Complications of Fungal Infection in the Sinuses

Chronic and acute fungal sinusitis caused by the fungi Aspergillus and mucormycosis is difficult to treat and potentially lethal, particularly in people with diabetes and compromised immune systems. Mucormycosis is particularly dangerous if it is not treated quickly. Fungal ball (mycetoma) is not invasive and is nearly always treatable with surgery. Recurrence is rare.

Asthma

The relationship between sinusitis and asthma is unclear. A number of theories have been proposed for a causal or shared association between sinusitis and asthma. Some include the following:

• Stimulation of nerve pathways, inflammation, and overproduction of mucus in the nasal passages and sinus cavities may eventually affect the airways in the lung, causing them to hyperreact.
• Breathing through the mouth when the sinuses are blocked allows in large particles that would other wise be filtered by the nasal defense system. Such particles could trigger allergic responses in the lungs that can trigger asthma in susceptible people.
• Air breathed through the mouth is colder than air warmed in the nasal passages. Cold air is a known trigger of asthma.
• Both may share similar immune abnormalities that cause inflammation in the airways in the lungs and sinuses.

Successful treatment of both allergic rhinitis and chronic sinusitis in children who also have asthma may reduce symptoms of asthma. It is particularly important to treat any coexisting bacterial sinusitis in people with asthma. They might not respond to asthma treatments unless the infection is cleared up first.

Effects of Chronic Sinusitis

Pain and other symptoms of chronic sinusitis can have significant effects on the quality of life. This condition can cause emotional distress, impair normal activity, and reduce attendance at work or school. According to the American Academy of Allergy, Asthma, and Immunology, the average sinusitis patient misses about four work days a year. In fact, a 2003 study placed sinusitis in the top 10 medical conditions that most adversely affect American employers. In addition, some people may lose their sense of smell. Surgery or medical treatments can help restore this sense.