What Causes Chronic Sinusitis?

What is chronic sinusitis?

Chronic sinusitis has several potential causes.
Chronic sinusitis has several potential causes.

Sinuses are hollow spaces in the skull. Chronic sinusitis occurs when the tissue lining the facial sinuses becomes inflamed for at least three months. Chronic sinusitis usually involves nasal airway swelling (rhinitis). Hence, it is also called chronic rhinosinusitis (CRS). Chronic sinusitis usually occurs as a result of repeated episodes of acute sinusitis that have not been managed appropriately. CRS is typically noninfective and occurs mainly due to allergies or medical conditions such as cystic fibrosis (a disease where the clearing of secretions by the nose and lungs is impaired). In CRS, normal drainage of secretions by the facial sinuses is impaired and there is inflammation and swelling of the tissues in the nose and sinuses causing nasal discharge and obstruction. CRS can affect both adults and children.

CRS is classified into three main categories

  • CRS without polyps: Polyps are abnormal tissue growths arising from mucosal linings.
  • CRS with polyps
  • Allergic fungal rhinosinusitis (AFRS): Occurs due to allergic reactions of the nose and sinuses to fungal spores.

What causes chronic sinusitis?

The causes of chronic sinusitis include the following

  • Nasal polyps: Polyps are small growths of the nasal lining that can cause obstruction of the ostium (sinus opening) preventing normal drainage and clearance of mucus out of the sinuses. They also obstruct the nasal passages.
  • Deviated nasal septum (DNS): The nasal septum divides the nose into two regions, the right and left nasal cavities. If the nasal septum is bent (deviated), it causes narrowing of the nasal airway and may obstruct the sinus opening. DNS can also worsen symptoms of chronic rhinosinusitis (CRS).
  • Systemic medical conditions: CRS can occur as a result of diseases such as cystic fibrosis where mucus clearance is impaired, human immunodeficiency virus (HIV), and other inflammatory and immune system-related diseases.
  • Recurrent respiratory tract infections: Recurrent infections (viral, bacterial, or fungal) in the upper and lower respiratory tract can cause chronic inflammation of the lining of the nose and sinuses leading to CRS.
  • Allergy: Inflammatory responses to allergens in the environment can cause chronic inflammation of the nose and sinuses.

What are the risk factors for chronic sinusitis?

The risk of chronic sinusitis increases due to the following

  • Deviated nasal septum (DNS)
  • Nasal polyps
  • Asthma
  • Aspirin sensitivity
  • Poor dental hygiene and dental infections
  • Immune system–related diseases such as human immunodeficiency virus/acquired immunodeficiency virus (HIV/AIDS)
  • Cystic fibrosis
  • Hay fever or other allergies 
  • Chronic exposure to pollutants such as cigarette smoke or industrial gases

What are the signs and symptoms of chronic sinusitis?

Common signs and symptoms of chronic sinusitis include the following

  • Nasal inflammation
  • Nasal itching 
  • Thick white or yellowish-white (yellowish discharge indicates superimposed bacterial infection) discharge from the nose
  • Postnasal drip (constant drainage of the mucus through the back of the nose and down the throat) causing discomfort and throat irritation 
  • Nasal obstruction (nose block) or congestion
  • Difficulty breathing through the nose
  • Pain, tenderness, and swelling around your eyes, cheeks, nose, or forehead
  • Reduced sense of smell and taste
  • Voice changes 
  • Ear pain (mainly due to blockage of the eustachian tube causing negative pressure in the ear)
  • Pain in the upper jaw and teeth, especially around the canines 
  • Cough
  • Recurrent throat clearing
  • Recurrent episodes of sore throat due to mouth breathing as a result of nasal blockage and postnasal drip
  • Halitosis (bad breath)
  • Disturbed sleep 
  • Inability to concentrate 
  • Fatigue


Common Allergies: Symptoms and Signs See Slideshow

How is chronic sinusitis treated?

Treatment options for chronic sinusitis include the following

  • Corticosteroids: Corticosteroids may be prescribed in the form of local nasal sprays, oral medications or as injections. Steroids help to suppress allergy, reduce inflammation and shrink tissue growth. Steroid sprays work locally in the nose and sinuses to reduce inflammation and open the nasal passages. Examples include fluticasone, mometasone and beclomethasone. Oral medications and injections are used to treat more severe cases, those who do not show improvement with sprays and those who have extensive nasal polyps.
  • Saline nasal irrigation: The nose may be irrigated with nasal sprays or solutions. This helps to clear the airway by flushing out mucus, crusts and pollutants.
  • Aspirin desensitization treatment: Those who have negative reactions to aspirin causing sinusitis can be treated by administering gradually increasing doses of aspirin under a doctor’s supervision until aspirin tolerance increases.
  • Antibiotics: Chronic rhinosinusitis (CRS) does not typically cause infections. However, antibiotics are required to treat secondary bacterial infections.
  • Immunotherapy: CRS occurring due to long-standing allergies can be treated with immunotherapy. This can help suppress the body's immune cells to reduce reactions to specific allergens. This can help prevent recurrence as well.
  • Surgery: Endoscopic sinus surgery may be performed in cases resistant to medical treatment or medication. An endoscope (a thin tube with a light and camera attached) and surgical instruments are inserted into the nose to perform surgery under anesthesia.
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