Sinusitis – Causes, Signs and symptoms

Sinusitis

Also called: Irritant Sinusitis, Infectious Sinusitis, Acute Sinusitis, Sinus Infection, Chronic Sinusitis, Acute Rhinosinusitis, Allergic Rhinosinusitis, Rhinosinusitis, Recurrent Acute Rhinosinusitis, Subacute Rhinosinusitis, Chronic Rhinosinusitis, Noninfectious Rhinosinusitis

Summary

Sinusitis, also known as rhinosinusitis, is an inflammation of the mucous membranes lining the paranasal sinuses, four pairs of cavities that connect the nose to the throat. About 37 million Americans are affected by sinusitis each year, according to the National Institutes of Health.

A cold or allergy usually creates the inflammation and congestion that prevents drainage of the warm, moist, mucus-filled sinus cavity. This creates a perfect breeding ground for viral, bacterial or fungal infections that can lead to sinusitis.

Sinusitis may be either acute or chronic:

  • Acute sinusitis lasts for just a few weeks and usually requires no treatment. In some cases, antibiotics may be used.
  • Chronic sinusitis lasts longer and can be more difficult to treat. However, treatment is essential, as long-term bouts of sinusitis can develop into dangerous medical conditions. Most cases of sinusitis in the United States are chronic. Chronic sinusitis afflicts more than 33 million Americans annually, according to the U.S. Centers for Disease Control and Prevention. 

In addition, sinusitis may be either infectious or noninfectious:

  • Infectious sinusitis is usually caused by a viral infection. Less frequently, it is the result of bacterial or fungal growth.
  • Noninfectious sinusitis is usually the result of allergies or other irritants.

Acute sinusitis and chronic sinusitis share many symptoms. One typical symptom shared by both forms is a sinus headache, a nonvascular headache caused by pressure changes in sinus cavities. Trapped air, pus and other secretions create pressure on the sinus wall. Pain, pressure or fullness is usually present in the cheeks, brow or forehead.

In diagnosing sinusitis, a physician will look for tenderness over the sinus cavities, swelling of the mucous glands, nasal secretions, postnasal drip and swelling around the eyes. A physician will also likely ask about any recent colds or history of allergies and whether a patient smokes. A sample of nasal discharge may be collected and tested for the presence of bacteria. Imaging tests also may be performed to help better define the extent of sinusitis in a patient and the degree of blockage present.

Acute sinusitis often resolves on its own without the need for treatment. If treatment does become necessary, decongestants or antibiotics may be prescribed. Chronic sinusitis can be more difficult to treat and may require treatment with several different medications, including antibiotics, decongestants, mucus-thinning medications, and antihistamines or anti-inflammatory corticosteroid nasal sprays (both of which are used to reduce swelling and mucus production).

During cold and flu season, several precautions can be taken to lessen the likelihood of contracting upper respiratory infections that can lead to sinusitis. People with seasonal allergies can also take steps to treat or prevent their symptoms. Researchers continue to look at new ways of treating sinusitis. For example, initial studies of certain antifungal nasal medications have shown them to be highly effective in treating chronic sinusitis. In addition, studies are being conducted to better understand how certain germs that contribute to ear infections may also contribute to sinusitis.

About sinusitis

Sinusitis, also known as rhinosinusitis, occurs when the linings of the sinuses and cavities of the nose become inflamed. About 37 million Americans are impacted by sinusitis each year, and Americans spend $5.8 billion annually treating the illness, according to the National Institutes of Health.

The body has four pairs of hollow sinuses located within the dense portions of the skull and bones of the head surrounding the nose. These paranasal sinuses connect the nose to the throat and allow for the exchange of mucus and air. They include:

  • Frontal sinuses (in the forehead)
  • Maxillary sinuses (behind the cheekbones)
  • Ethmoid sinuses (between the eyes)
  • Sphenoid sinuses (behind the eyes)

The sinuses help insulate the skull, reduce its weight and allow the voice to resonate within it. The membranes in the sinuses produce mucus, which moistens and cleanses the nasal passages. They also warm air that is breathed in through the nose before it moves on to the lungs.

Sinusitis can develop when colds, allergies or other conditions damage the cells of the sinus lining, causing it to swell and thicken. This impairs the sinuses by blocking the small openings (ostia) between the sinuses and the nose and preventing the free exchange of air and mucus. When this happens, symptoms often result. Trapped air in the sinuses creates pressure on the sinus wall, causing pain. Mucus and pus trapped in the sinuses become breeding grounds for viruses, bacteria and fungi.

Long-term sinusitis can cause serious health problems if left untreated. Conditions known to develop over time include:

  • Infection of the eye socket (orbital cellulitis), leading to vision loss
  • Infection of the brain lining (meningitis), which can cause brain damage
  • Infection of the bones of the face (osteomyelitis)
  • Chronic facial pain
  • Loss of sense of smell
  • Chronic headaches
  • Chronic nasal and sinus congestion
  • Chronic bad breath
  • Blood vessel complications that can cause aneurysms (ballooning of blood vessels) and blood clots

Types and differences of sinusitis

Every bout of sinusitis can be classified according to the duration of the inflammation and whether or not it is caused by an infection. The length of inflammation is divided into two categories: chronic and acute. Most cases of sinusitis in the United States are chronic. Chronic sinusitis afflicts more than 33 million Americans annually, according to the U.S. Centers for Disease Control and Prevention. 

Acute sinusitis is characterized by fewer than three or four weeks of symptoms. Some experts also use the term subacute sinusitis to refer to an illness that lasts between four and eight weeks. A viral infection usually causes acute sinusitis, which often begins suddenly after a bout with a common cold. However, allergies can also be the source of acute sinusitis. Several episodes of acute sinusitis in the span of a year are referred to as recurrent sinusitis.

Acute sinusitis causes postnasal drainage and discomfort in the cheeks, forehead and eyes. Nasal congestion, cough, headache, toothache and fever are also typical symptoms. Many cases do not require medical treatment, but those caused by bacterial infection must be treated with antibiotics.

Chronic sinusitis is defined as two or more episodes per year of sinusitis. Other experts define chronic sinusitis as any case of the illness that lasts for at least eight weeks. Bouts of chronic sinusitis typically last longer than three months and can be caused by infections (treated with antibiotics) or a chronic inflammatory disorder similar to bronchial asthma (treated with corticosteroids).

Chronic sinusitis is often the result of untreated acute sinusitis. Symptoms are similar to those of acute sinusitis, except fever is usually not present. Nasal polyps (tissue growths) also occur in a minority of cases and cause additional cavity blockage. Allergies, such as hayfever  or mold allergies, often play a major role in chronic sinusitis by keeping the sinus membranes inflamed for extended periods of time. Sometimes, structural problems in the nose are the root cause of chronic sinusitis. Surgery may be needed to correct the problem in such situations.

Sinusitis may also be classified as either infectious or noninfectious.

Infectious sinusitis usually stems from a viral infection. Less frequently, it is the result of bacterial or fungal growth. Types of infectious sinusitis include:

  • Viral sinusitis. Usually occurs due to an upper respiratory tract infection. Viruses attack the lining of the sinuses, which causes swelling of nasal tissues.
  • Bacterial sinusitis. May be caused when bacteria grow inside the sinuses. Swelling or narrowing of the eustachian tube (passageway extending from the back of the throat and nose to the ears) due to inflammation prevents drainage from the middle ear, which may also cause bacterial sinusitis.
  • Fungal sinusitis. Usually occurs in people with repressed immune systems, allergies to environmental fungi or those who have experienced injuries to the sinuses. Some studies have shown that fungal sinusitis may be more common than previously believed.

Noninfectious sinusitis is usually the result of allergies or other irritants. Types of noninfectious sinusitis include:

  • Allergic sinusitis. Pollens, animal dander or other allergens trigger an allergic reaction, causing the lining of the nose and sinuses to become inflamed.
  • Aspirin sensitivity sinusitis. Occurs in some individuals who have severe asthmatic responses to aspirin and other pain medications, such as ibuprofen.
  • Cold air sinusitis. Produces symptoms when an individual is exposed to cold air.

Potential causes of sinusitis

There are many causes of sinusitis. Anything that interferes with airflow into the sinuses and mucus drainage out of the sinuses can cause inflammation and sinusitis.

Some of the medical conditions that can cause sinusitis include:

  • Colds, viruses and other respiratory infections. These infections inflame the sinuses and cause the body to react to the infection by producing mucus and directing white blood cells to the lining of the nose. This causes congestion and swelling of the nasal passages and the adjacent mucous membranes of the sinuses. As openings of the sinuses narrow, air and mucus become trapped inside, creating the conditions that lead to sinusitis.
  • Allergies. In some people, the immune system mistakenly recognizes harmless elements (e.g., pollen, pet dander, dust mites) as threats, triggering a reaction that resembles a cold with symptoms such as stuffy nose, itchy eyes and coughing. This can lead to the development of sinusitis.
  • Exposure to fungi. Fungi can cause a particular form of sinusitis known as fungal sinusitis. While fungi can be found throughout the environment, they typically are harmless to people unless they have immune system problems or are allergic to fungi.
  • Tumors or growths in the sinuses, such as nasal polyps (small, round growths).
  • Aspirin sensitivity. Sinusitis may occur when people with sensitivity to aspirin take the medication.
  • Environmental factors. Pollutants may lead to congestion that causes sinusitis. Other causes may include damp weather, particularly in northern climates.
  • Overuse of decongestant nasal sprays. Using nasal sprays for longer than recommended can lead to “rebound congestion” that inflames the sinuses.
  • Structural abnormalities and other blockages. These can be natural, such as a crookedness in the wall dividing the nostrils (deviated septum), or caused by trauma. An injury, such as a fractured facial bone, can obstruct one or more sinus cavities leading to sinusitis.
  • Dental infections that spread to the sinuses.
  • Use of illegal drugs that are snorted, such as cocaine.
  • Asthma. People with asthma may have hyperactive nasal airways, which can lead to sinusitis. Also, pus inside an infected nasal cavity that manages to drain into the throat can sometimes trigger an asthma attack.
  • Failure of the cilia to move mucus. The cilia are tiny hairs of mucus-producing cells that move mucus out of the sinuses and into the nose and throat. Tobacco smoke is known to damage the cilia. Several health disorders can also complicate this process, including cystic fibrosis (a hereditary disorder affecting the lungs and digestive tract), Kartagener’s syndrome (a congenital disorder that consists of three sinus afflictions), immotile cilia syndrome (a disorder that causes failure of the cilia to clear mucus), and immune deficiency diseases such as AIDS.

    As the sinuses become blocked, mucus inside the sinus cavity cannot drain to the back of the throat. This provides a breeding ground for viruses and bacteria to grow, resulting in infection. Pus then starts to form, and has nowhere to drain, further exacerbating the situation.

Signs and symptoms of sinusitis

Acute sinusitis and chronic sinusitis share many symptoms. One typical symptom shared by both forms is a sinus headache, a nonvascular headache caused by pressure changes in sinus cavities. Trapped air, pus and other secretions create pressure on the sinus wall. Pain, pressure or fullness is usually present in the cheeks, brow or forehead.

Other symptoms of sinusitis include:

  • Aching in the upper jaw or teeth
  • Cold symptoms that last more than a week
  • Ear pain
  • Fatigue
  • Weakness
  • Cough
  • Nasal congestion
  • Profuse, thick, colored (especially green) nasal discharge
  • Bad breath
  • Bad-tasting postnasal drip
  • Headache when leaning forward
  • Reduced sense of smell
  • Sore throat (resulting from postnasal drip)

Although people with sinusitis typically have pain or tenderness in several locations, certain symptoms may indicate which of the sinuses are affected. These include:

  • Facial pain. Pain when the forehead is touched indicates inflammation of the frontal sinuses (located in the forehead).
  • Achiness of the upper jaw and teeth, and tenderness in the cheeks when touched. This indicates infection in the maxillary sinuses (located behind the cheekbones).
  • Pain between the eyes, swelling of the eyelids and tissues around the eyes. This indicates inflammation of the ethmoid sinuses (located between the eyes), which may also cause tenderness when the nose is touched and loss of smell.
  • Earaches, neck pain and a deep ache at the top of the head indicate infection of the sphenoid sinuses (located behind the eyes).

Where symptoms of acute and chronic sinusitis differ include:

  • Duration of symptoms. Acute sinusitis tends to occur during a period of a month or less, while chronic sinusitis can stretch on for months and tends to recur.
  • Severity of symptoms. Symptoms tend to be more pronounced in acute sinusitis and more subtle in chronic sinusitis.
  • Fever. Acute sinusitis is often accompanied by low-grade fever, but this is rarely the case in chronic sinusitis.

Patients should seek prompt medical attention if they have sinusitis and experience any of the following symptoms (which may indicate complications have developed):

  • Fever greater than 100.5 degrees Fahrenheit (38 degrees Celsius)
  • Pain, swelling or redness on the face or around the eyes
  • Severe headache
  • Confusion
  • Stiff neck

Diagnosis methods for sinusitis

A physician may be able to diagnose whether a patient has sinusitis and what may be causing the inflammation. An accurate diagnosis is crucial because different types of sinusitis require different treatments. However, this can be difficult because the symptoms of sinusitis are often similar to those of colds and allergies.

A physical examination, patient medical history and list of symptoms are important components necessary for a diagnosis to be made. A physician will look for tenderness over the sinus cavities, swelling of the mucous glands, nasal secretions, postnasal drip and swelling around the eyes. A physician will also likely ask about any recent colds or history of allergies, and whether a patient smokes. A sample of nasal discharge may be collected and tested for the presence of bacteria.

A sinus x-ray, magnetic resonance imaging (MRI) or computed axial tomography (CAT) scan may help better define the extent of sinusitis in a patient and the degree of blockage present. A nasal endoscopy, called a rhinoscopy, uses an endoscope (thin, flexible tube and camera) to help a physician examine the area where the sinuses and middle ear drain into the nose.

Special tests known as cultures may be performed to identify the presence of bacteria or fungi. Biopsies of the cells lining the nasal cavity may also reveal important information. Blood tests may be performed to rule out conditions associated with sinusitis, such as immune system deficiencies or cystic fibrosis (a hereditary disorder affecting the lungs and digestive tract).

If allergies are a suspected cause of sinusitis, allergy skin testing or other diagnostic tests may be used to identify the type of allergies that may be triggering symptoms.

Treatment options for sinusitis

Treatment of sinusitis depends on whether the problem is acute (short-term and more severe) or chronic (long-lasting and more mild).

Acute sinusitis often resolves on its own without the need for treatment. If treatment does become necessary, decongestants may be prescribed to open the sinuses and reduce the volume of mucus that is present. A course of antibiotics over 10 days to two weeks is usually successful in curing an infection caused by bacteria.

Chronic sinusitis can be more difficult to treat. Many different medications may be necessary to successfully treat this condition. These medications may include antibiotics (when bacterial infection is involved), decongestants, mucus-thinning medications, and antihistamines or anti-inflammatory corticosteroid nasal sprays (both of which are used to reduce swelling and mucus production). For patients using nasal sprays, physicians may recommend using a saltwater or saline wash before the spray to help remove mucus and bacteria from the nose and sinuses.

There are some concerns about using corticosteroid nasal sprays to treat chronic sinusitis for long periods of time, because the long-term effects of these medications are not known. Therefore, a physician will weigh the potential benefits and risks of such medications before prescribing them. Nasal corticosteroid sprays are usually preferred to oral corticosteroids because they affect one localized area of the body, while systemic medications such as pills or liquids may affect the entire body. Nonetheless, oral corticosteroids may be prescribed in cases of severe sinusitis.

In some cases, allergy shots (immunotherapy) may be helpful in reducing sensitivity to certain allergens for people with chronic allergic sinusitis.

Over-the-counter pain relievers may be recommended for patients with sinusitis. These medications may help relieve sinus headaches and lessen fever. Patients should always consult with a physician before taking any type of medication, including over-the-counter remedies.

Some physicians may recommend alternatives to medications that may help alleviate symptoms associated with sinusitis. These techniques help to keep nasal passages moist, which can reduce nasal congestion. These non-drug techniques may include:

  • Breathing in hot, moist air – such as from steaming water in a bowl – for 10 minutes two to four times a day. Patients should wear a towel over their heads to prevent the steam from escaping.
  • Applying hot packs to the face, which helps to ease facial pain.
  • Rinsing nasal cavities with saltwater solutions. This can help remove mucus and bacteria from the nose and sinuses.

For some patients, surgery may be necessary to treat sinusitis. This is more common in adults with a physical abnormality that is responsible for symptoms, such as nasal polyps (small, grape-like growths), crookedness in the wall dividing the nostrils (deviated septum) or other physical problems. It may also be used as a last resort when medications have failed. During surgery, the natural openings of the sinuses may be enlarged to facilitate drainage. A thin, flexible tube called an endoscope is used, and serious complications are rare.

In children, the removal of nose and throat lymphoid tissue known as the adenoid often eliminates the blockage causing problems.

Patients who suffer from some forms of fungal sinusitis may require surgery to remove the fungus and prevent damage to the sinuses, eyes or brain.

Prevention methods for sinusitis

During cold and flu season, several precautions can be taken to lessen the likelihood of contracting upper respiratory infections that can lead to sinusitis. People with seasonal allergies can also take steps to treat or prevent their symptoms. The fewer cold and allergy symptoms that develop, the less likely that congestion will occur and lead to sinusitis.

To prevent colds and allergies that can lead to sinusitis:

  • Eat a nutritious diet, including plenty of fruits and vegetables. These are rich in antioxidants and other chemicals that can boost immune system function.
  • Exercise regularly. This helps the body fight infection and reduce stress (which can leave an individual more vulnerable to sickness).
  • Wash hands often, particularly after shaking hands with others.
  • Get a yearly flu vaccine.
  • Drink plenty of fluids. Eight glasses of water or more a day are recommended to keep the body hydrated, which thins nasal secretions and promotes drainage.
  • Avoid consumption of caffeine and alcohol. Foods or beverages with caffeine can dehydrate the body, which thickens nasal mucus and makes it less likely to drain. Mucus that fails to drain is a breeding ground for viruses and bacteria that can cause sinusitis. In addition, alcohol can cause sinus membranes to swell, which also blocks drainage.
  • Avoid exposure to allergens both inside and outside the home. Patients should make their home environment as allergen-free as possible, and avoid contact with outdoor allergens to the greatest extent possible.
  • Avoid tobacco smoke or polluted air. Both can trigger inflammation of the lining of the sinuses and nose.
  • Install a humidifier in the home, or at least the bedroom. This keeps the air moist, which may help reduce nasal congestion. It is important to frequently clean a humidifier to avoid the spread of germs.
  • Avoid blowing the nose with great force. This can push bacteria into the sinuses. Instead, patients should gently blow one nostril at a time, while blocking the other.
  • Patients should avoid air travel during periods when they have sinusitis. If travel must be undertaken, decongestants can reduce pressure inside the sinuses. However, patients should not take any medication without first consulting a physician.

Ongoing research regarding sinusitis

Researchers continue to look at new ways of treating sinusitis. For example, initial studies of certain antifungal nasal medications have shown them to be highly effective in treating chronic sinusitis. However, these results have not been duplicated in all studies and further research is required before this approach can be deemed effective.

In addition, studies are being conducted to better understand how certain germs that contribute to ear infections may also contribute to sinusitis. It is believed that at least two-thirds of sinusitis cases caused by bacteria stem from these germs. Experts hope that understanding how these germs become infectious may help lead to future vaccine strategies to reduce or eliminate certain types of sinusitis.

Questions for your doctor regarding sinusitis

Preparing questions in advance can help patients to have more meaningful discussions with health professionals regarding their conditions. Patients may wish to ask their doctor the following questions related to sinusitis:

  1. Do my symptoms suggest that I have sinusitis?
  2. What type of sinusitis do I have?
  3. What may have caused me to develop this condition?
  4. What treatments are available to me?
  5. Will I require surgery?
  6. When can I expect my symptoms to subside?
  7. Am I at risk for developing sinusitis-related complications?
  8. Will sinusitis have an effect on my sense of smell?
  9. Am I likely to develop sinusitis again? If so, how often?
  10. What steps can I take to prevent sinusitis in the future?
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