Causes of Rhinosinusitis

Viruses. Acute viral rhinosinusitis can be caused by over 200 different viruses. Some of the most frequent ones are rhinoviruses (25%–80%), followed by coronaviruses (10%–20%), influenza viruses (10%–15%) and adenoviruses (5%). No virus whatsoever is detected in 20%–30% of cases. The proportion may vary depending on the time of year, the population group being analysed or the detection method. The proportion tends to be higher in autumn and winter.

Bacteria. When the symptoms get worse after 5 days or persist for more than 10 days, this is called acute bacterial it is called post-viral rhinosinusitis. To diagnose bacterial rhinosinusitis, certain long-lasting symptoms are required, along with at least 3 of the following: fever > 38°C, worsening of the disease, unilateral disease, severe facial pain and abnormal blood test results. According to the European position paper on rhinosinusitis and nasal polyps (EPOS 2012) the bacteria most frequently isolated are Streptococcus pneumoniae, Haemophilus influenzae and Moxarella catarrhalis. Other species, such as streptococci, anaerobic bacteria and Staphylococcus aureus, are also isolated at lower percentages.

Chronic alteration to mucociliary transport. It is characterised by cough, rhinitis and chronic sinusitis due to abnormal ciliary function in the respiratory tract. It manifests in diseases such as primary ciliary dyskinesia or Kartagener’s syndrome.

Mucus with altered characteristics as occurs in cases of cystic fibrosis. In this disease, the patient’s mucus is thicker and harder to transport.

Asthma. Asthma shares a close association with chronic rhinosinusitis. In fact, rhinosinusitis treatment usually improves control over the patient’s asthma.

Aspirin-Exacerbated Respiratory Disease – AERD. It is a disorder of the metabolism of these drugs that can trigger a chronic inflammation of the lower and upper airway (paranasal sinuses).

Immune system disorders. Such as HIV or common variable immunodeficiency.

Allergic rhinitis or another atopic reaction that affects the paranasal sinuses. Allergic rhinitis causes swelling in the nasal mucosa that can partially block the drainage holes from the paranasal sinuses.

Environmental factors. For example, regular exposure to contaminants such as tobacco smoke.

Gastro-oesophageal reflux disease (GERD). Studies have found that GERD affects 52.4% of people with rhinosinusitis. Although GERD does appear to be more common in poorly controlled cases of rhinosinusitis, further studies are needed to confirm this finding or to determine whether reflux treatment leads to any improvement.

Anatomical variations. Septal deviation, alterations to the uncinate process or concha bullosa.

Genetics. There does not appear to be a single gene or group of genes involved in the cause, progression or response to treatment of rhinosinusitis. However, some mutations in the TAS2R receptors appear to be involved.