Acute rhinosinusitis
Inflammation of the nasal mucosa and paranasal sinuses that follows blockage of their narrow drainage pathways, almost always viral and self-limiting, with antibiotics reserved for the minority who develop true bacterial superinfection or complications.
First principles
The sinuses only stay healthy if their narrow drainage openings (ostia) stay open
The paranasal sinuses are air-filled cavities lined by ciliated mucosa that drain into the nasal cavity through small openings called ostia, particularly the narrow ostiomeatal complex. A viral upper respiratory tract infection causes mucosal inflammation and oedema that swells this lining and narrows or blocks the ostia, exactly as the Eustachian tube blocks in otitis media. Once drainage is blocked, mucus accumulates within the sinus, ciliary clearance fails, and the trapped secretions and negative pressure produce the facial pain, pressure and congestion of rhinosinusitis.
Educational content pending clinical review. Not medical advice.