Pressure changes causing irritation - diving, air travel
Anatomical - older age resulting in weaker cartilage and less supported nasal passage, deviated septum, polyps, tumour
Impaired ciliary function - cystic fibrosis and primary ciliary dyskinesia, smoking
Immunodeficiency
Most common causes:
Most common = viral URTI
Common viral pathogens = rhinovirus, parainfluenza, influenza
Bacterial infection can occur when drainage of the sinus if affected, leading to blockage and build-up of bacteria - bacterial infection secondary to viral infection
Pathophysiology:
Virus affects nasal mucosa first and causes symptoms - nose blowing prompts propagation of infection to paranasal sinuses
As infection develops it leads to excess sinonasal secretions, increased vascular permeability and mucosal oedema
The inflammation of sinonasal mucosa obstructs sinus ostia (bony opening in sinus), leading to mucus retention, decreased mucociliary clearance, increased pressure causing pain
This predisposes to secondary bacterial infection
Typical symptoms:
Nasal congestion
Nasal discharge - purulent
Facial pressure/pain/headache - worse on bending forward
Anosmia
Ear pain - often due to eustachian tube dysfunction due to obstruction
Fever
Halitosis - purulent mucus drips down back of throat