Rhinosinusitis

Rhinosinusitis is inflammation of the nasal cavity and paranasal sinus mucosa. Most cases begin with a viral upper-respiratory infection. Inflammation causes the mucosa to swell around the sinus openings, or ostia, so mucus cannot drain normally. Mucociliary clearance slows, secretions collect, and the patient develops nasal obstruction, pressure, reduced smell, postnasal drainage, or cough. Stagnant secretions can permit bacterial overgrowth, but nasal discharge that becomes yellow or green does not prove a bacterial infection. The more useful clues are the illness trajectory, associated fever or facial pain, and whether the patient improves and then deteriorates. Allergic rhinitis, nasal polyps, a deviated septum, smoke exposure, dental infection, and immunosuppression can increase the likelihood of persistent or recurrent symptoms by promoting mucosal swelling, impaired drainage, or bacterial growth.