Contents of this article
What is Sinusitis
Sinusitis refers to the inflammation and swelling of the sinus cavities, which are air-filled spaces located within the bones around the nose.
The sinuses are air-filled cavities in the skull, located within the bony structure of the cheeks, behind the forehead and eyebrows, situated on either side of the bridge of the nose, posterior to the nasal bones directly anterior to the brain. Healthy sinuses contain no bacteria or other germs.
Most of the time, mucus is able to drain out and air is able to flow through the sinuses. When the sinus openings become blocked or too much mucus builds up, bacteria and other germs can grow more easily.
Fredisposing factors of Sinusitis
Several factors can increase your risk of getting a sinus infection:
- Allergic rhinitis (hay fever)
- A previous cold
- Large adenoids
- Smoking
- Seasonal allergies
- Smoking and exposure to smoke
- Structural problems within the sinuses, such as nasal polyps.
- A weaken immune system or immunocompromised individual
Types of Sinusitis
There are three main types of sinusitis
Acute sinusitis.
It is caused by bacteria growing in the sinuses. It usually starts with cold-like symptoms such as a runny, stuffy nose and facial pain. Symptoms may start suddenly and last 2 to 4 weeks.
Subacute sinusitis.
Symptoms and swelling lasts for 4 to 12 weeks.
Chronic sinusitis
Symptoms last 12 weeks or longer. It may be caused by bacteria or a fungus Recurrent sinusitis happens several times with the year.
Pathophysiology of Sinusitis
The pathophysiology of sinusitis involves several interrelated factors:
Obstruction of Sinus Openings:Sinusitis often begins with an obstruction or blockage of the openings (ostia) that connect the sinuses to the nasal passages. This can be caused by various factors, including viral infections, allergies, anatomical abnormalities (deviated septum), or polyps in the nasal cavity. When these ostia become blocked, mucus cannot drain properly from the sinuses.
Impaired Mucociliary Clearance:The normal function of cilia (tiny hair-like structures lining respiratory epithelium) is essential for clearing mucus and debris from the sinuses towards the nasal cavity. In sinusitis, inflammation impairs ciliary movement and reduces mucociliary clearance, leading to stagnant mucus accumulation within the sinus cavities.
Bacterial Colonization and Infection:Stagnant mucus provides a favorable environment for bacterial growth within the sinuses. Secondary bacterial infection commonly occurs in cases where acute viral upper respiratory tract infections predispose individuals to develop sinusitis or when chronic inflammation persists. Common bacteria involved include Streptococcus pneumoniae, Haemophilus influenzae, and Moraxella catarrhalis.
Inflammatory Response:The presence of pathogens triggers an immune response characterized by local release of pro-inflammatory cytokines such as interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-alpha), and interleukin-8 (IL-8). These inflammatory mediators cause vasodilation and increased vascular permeability in blood vessels near affected areas leading to tissue edema.
Sinonasal Tissue Edema:Inflammation-mediated vasodilation and increased vascular permeability result in tissue edema within the sinus cavities and nasal passages. This edema further contributes to blockage of sinus openings, reducing effective drainage and perpetuating the cycle of inflammation.
Increased Mucus Production:In response to inflammation, goblet cells in the respiratory epithelium secrete an excessive amount of mucus. This increased mucus production is part of the body's defense mechanism against pathogens but can exacerbate congestion and obstruction within the sinuses.
Osteomeatal Complex Dysfunction:The osteomeatal complex refers to a narrow passage connecting several sinuses (maxillary, ethmoidal) with the nasal cavity. Dysfunction or blockage at this site due to swelling or anatomical variations can lead to impaired drainage from these sinuses, contributing to chronic sinusitis.
The combination of these pathophysiological mechanisms leads to symptoms commonly associated with sinusitis, including facial pain, nasal congestion, rhinorrhea, coughing, headache, and reduced sense of smell.
Signs & Symptoms of Sinusitis
- Bad breath
- Cough, often worse at night
- Fatigue and sometimes malaise
- Fever
- Pressure-like pain, pain behind the eyes, toothache, or tenderness of the face
- Sore throat
- Postnasal drip
- Discolored nasal discharge (greenish in color)
- Nasal stuffiness or congestion
- Frontal headaches
Diagnostic Investigation of Sinusitis
- CT scan of the sinuses
- MRI of the sinuses
- Allergy testing
- Blood tests
- Ciliary function test
- Nasal culture
- Nasal cytology
Medical Management of Sinusitis
Antibiotics are standard treatments for bacterial sinus infections.
- Allergy shots (immunotherapy) to help prevent the disease rebound
- Avoiding allergy triggers
- Antihistamines and nasal decongestant sprays prevent and reverse inflammation and swelling in the nasal passages and sinus openings
- Antihistamines to block inflammation caused by an allergic reaction
- Topical nasal corticosteroids
- Nasal saline washes rinses and clear thickened secretions from the nasal passages
Prevention of Sinusitis of Sinusitis
- Proper and regular hand washing
- Get vaccinated such as the flu vaccine and pneumococcal vaccine.
- Avoid close contact with people who have colds or other upper respiratory infections.
- Avoid smoking and other pollutants
- Control your allergies if you have them.
- Reduce stress.
- Drink plenty of fluids to increase moisture in your body.
- Use a humidifier to increase moisture in your nose and sinuses.
References
- Fokkens WJ et al., European Position Paper on Rhinosinusitis - Rhinology
- Bachert C et al., Chronic rhinosinusitis: An enhanced understanding of its pathophysiology based on genetics research - Journal Allergy Clinical Immunology
- Rosenfeld RM et al., Clinical Practice Guideline Adult Sinusitis - Otolaryngology-Head Neck Surgery
- https://www.pennmedicine.org/for-patients-and-visitors/patient-information/conditions-treated-a-to-z/sinus-infections-sinusitis
