From the Guidelines
Chronic sinusitis is a complex condition with multiple risk factors, including allergies, nasal polyps, deviated septum, respiratory tract infections, and conditions that affect immune function, as well as environmental factors and medical conditions such as cystic fibrosis, GERD, and asthma. The most recent and highest quality study, 1, suggests that chronic rhinosinusitis (CRS) is a syndrome with a multifactorial aetiology resulting from a dysfunctional interaction between various environmental factors and the host immune system.
Key Risk Factors
- Allergies: cause inflammation of the nasal passages and sinuses, leading to blockage and infection
- Nasal polyps: obstruct sinus drainage
- Deviated septum: block normal sinus drainage pathways
- Respiratory tract infections: particularly viral infections that evolve into bacterial infections, often precede chronic sinusitis
- Conditions that affect immune function: such as immunodeficiency disorders, HIV/AIDS, or medications that suppress the immune system, increase susceptibility
- Environmental factors: like cigarette smoke, air pollution, and exposure to irritants can damage the protective lining of the sinuses
- Medical conditions: including cystic fibrosis, which causes thick mucus that blocks sinuses, gastroesophageal reflux disease (GERD), and asthma are also associated with chronic sinusitis
Additional Considerations
- Regular exposure to high-altitude environments or frequent flying can create pressure changes that affect sinus function
- Dental infections can sometimes spread to the maxillary sinuses
- Understanding these risk factors is important for prevention and appropriate management of chronic sinusitis, as stated in 1 and 1.
From the Research
Risk Factors for Chronic Sinusitis
- Anatomic factors, such as disturbances in mucociliary clearance and ostial function, can contribute to the development of chronic sinusitis 2, 3
- Microbial pathogens, including bacteria, viruses, and fungi, can cause sinus infections and contribute to the development of chronic sinusitis 2, 3, 4
- Inflammatory factors, such as the presence of chronic inflammatory cells, eosinophils, and IL-5-producing T lymphocytes, can play a role in the pathogenesis of chronic sinusitis 2, 5
- Allergic reactions, such as atopy and asthma, can increase the risk of developing extensive chronic sinusitis 5
- Age, with individuals over 50 years old being more likely to develop extensive disease 5
- Eosinophilia, with an eosinophil count greater than or equal to 200/microl being strongly associated with extensive disease 5
Microbiological Risk Factors
- Viral infections, such as rhinoviruses, influenza viruses, and parainfluenza viruses, are common causes of sinusitis 4
- Bacterial infections, such as Streptococcus pneumoniae, Haemophilus influenzae, Moraxella catarrhalis, and Streptococcus pyogenes, can cause secondary infections in sinusitis 4
- Fungal infections, such as allergic fungal sinusitis, can cause chronic sinusitis 2, 4
- Anaerobic bacteria, such as Prevotella and Porphyromonas, Fusobacterium and Peptostreptococcus spp., can be isolated from patients with chronic sinusitis 4