What causes acute sinusitis?
Most cases of acute sinusitis start with a common cold, which is caused by a virus. Colds can inflame your sinuses and cause symptoms of sinusitis. Both the cold and the sinus inflammation usually go away without treatment within 2 weeks. If the inflammation produced by the cold leads to a bacterial infection, however, then this infection is what health experts call acute sinusitis.
The inflammation caused by the cold results in swelling of the mucous membranes (linings) of your sinuses, and this can lead to air and mucus becoming trapped behind the narrowed openings of the sinuses. When mucus stays inside your sinuses and is unable to drain into your nose, it can become the source of nutrients (material that gives nourishment) for bacteria.
Most healthy people harbor bacteria, such as Streptococcus pneumoniae and Haemophilus influenzae, in the nose and throat, and the bacteria cause no problems. But when you have a cold, you tend to sniff or to blow your nose, and these actions cause pressure changes that can send bacteria inside the sinuses. If your sinuses then stop draining properly, bacteria that may have been living harmlessly in your nose or throat can begin to multiply in your sinuses, causing acute sinusitis.
People who suffer from allergies that affect the nose (like pollen allergy, also called "hay fever"), as well as people who may have chronic nasal symptoms not caused by allergy, are also prone to develop episodes of acute sinusitis. The chronic nasal problems cause the nasal membranes to swell, and the sinus passages become blocked in a manner similar to that described above for the common cold. The normally harmless bacteria in the nose and throat again lead to acute sinusitis.
Rarely, fungal infections can cause acute sinusitis. Although fungi are abundant in the environment, they usually are harmless to healthy people because the human body has a natural resistance to fungus. However, in people whose immune system is not functioning properly, fungus, such as Aspergillus, can cause acute sinusitis. (Aspergillus is commonly found growing on dead leaves, stored grain, compost piles, or in other decaying vegetation.)
In general, people who have reduced immune function (such as those with primary immune deficiency disease or HIV infection) or abnormalities in mucus secretion or mucus movement (such as those with cystic fibrosis) are more likely to suffer from sinusitis.
What are the symptoms of acute sinusitis?
One of the most common symptoms of sinusitis is pain, and the location depends on which sinus is affected.
- If you have a pain in your forehead over the frontal sinuses when you are touched, your frontal sinuses may be inflamed.
- If your upper jaw and teeth ache, and your cheeks become tender to the touch, you may have an infection in the maxillary sinuses.
- If you have swelling of the eyelids and tissues around your eyes, and pain between your eyes, you may have inflammation of the ethmoid sinuses that are near the tear ducts in the corner of your eyes. Ethmoid inflammation also can cause a stuffy nose, a loss of smell, and tenderness when you touch the sides of your nose.
- If you have earaches, neck pain, and deep achiness at the top of your head, you may have infection in the sphenoid sinuses, although these sinuses are less frequently affected.
Most people with sinusitis have pain or tenderness in several locations, and their symptoms usually do not clearly indicate which sinuses are inflamed.
In addition to the pain, people with sinusitis frequently have thick nasal secretions that are yellow, green, or blood-tinged. Sometimes these secretions, referred to as post-nasal drip, drain in the back of the throat and are difficult to get rid of. Also, sinusitis is strongly associated with nasal symptoms such as a stuffy nose, as well as with a general feeling of fullness over the entire face.
Less common symptoms of sinusitis can include:
- Decreased sense of smell
- Cough that may be more severe at night
- Sore throat
- Bad breath
On rare occasions, acute sinusitis can result in brain infection and other serious complications.
How is acute sinusitis diagnosed?
Because your nose can get stuffy when you have a condition like the common cold, you may confuse simple nasal congestion with sinusitis. A cold, however, usually lasts about 7 to 14 days and goes away without treatment. Acute sinusitis often lasts longer and typically causes more symptoms than a cold.
Your healthcare provider can usually diagnose acute sinusitis by noting your symptoms and doing a physical examination, which includes examining your nasal tissues. If your symptoms are vague or persist, your healthcare provider may order a computed tomography (CT) scan, a form of X-ray, to confirm that you have sinusitis.
How is acute sinusitis treated?
If you have acute sinusitis, your healthcare provider may recommend:
- Antibiotics to control a bacterial infection, if present
- Pain relievers to reduce any pain
- Decongestants to reduce congestion
Even if you have acute sinusitis, your provider may choose not to use an antibiotic because many cases of acute sinusitis will end on their own. But if you do not feel better after a few days you should contact your provider again.
You should use over-the-counter or prescription decongestant nose drops and sprays only for few days. If you use these medicines for longer periods, they can lead to even more congestion and swelling of your nasal passages.
If you have an allergic disease along with sinusitis, you may also need medicine to control allergies. This may include a nasal steroid spray that reduces the swelling around the sinus passages and allows the sinuses to drain. If you already have asthma and then get sinusitis, your asthma may worsen. You should stay in close touch with your healthcare provider to modify your asthma treatment if needed.
How can sinusitis be prevented?
There are no methods that have been scientifically tested and proven to prevent acute sinusitis. However, your healthcare provider may recommend a variety of measures that may provide you with some benefit.
- Keep your nose as moist as possible with frequent use of saline (salt) sprays.
- Avoid very dry indoor environments and use a humidifier, if necessary. But be aware that if you have allergies to molds, house dust mites, or cockroaches, a humid environment may also create problems.
- Avoid exposure to irritants, such as cigarette and cigar smoke or strong odors from chemicals.
- Avoid exposure to anything you're allergic to. If you have not been tested for allergies and you are getting frequent sinus infections, ask your healthcare provider to give you an allergy evaluation or to refer you to an allergy specialist.
- Avoid long periods of swimming in pools treated with chlorine, which irritates the lining of the nose and sinuses.
- Avoid water diving, which forces water into the sinuses from the nasal passages.
You may find that air travel poses a problem if you are suffering from sinusitis. As air pressure in a plane is reduced, pressure can build up in your head, blocking your sinuses or the eustachian tubes in your ears. As a result, you might feel discomfort in your sinuses or middle ear during the plane’s ascent or descent. Some health experts recommend using decongestant nose drops or sprays before a flight to avoid this problem.
Reference: The National Institute of Allergy and Infectious Diseases
Last updated April 20, 2017