How is sinusitis diagnosed?

The diagnosis of Acute sinusitis is fairly easy and a plain X-ray of the paranasal sinuses (PNS) usually confirms the diagnosis.

In contrast to the relative ease of diagnosing acute sinusitis, diagnosis of headache and facial pain associated with chronic sinus disease requires careful history and meticulous evaluation.  General headlight examination of the nose and X-ray of the PNS may be normal.  The severity of the head and facial pain is variable and pain may be absent.  Accurate diagnosis of chronic sinus disease therefore requires a careful history, comprehensive nasal endoscopic examination, and CT scan of the sinus area. Comprehensive nasal endoscopy is performed using surface anaesthesia in the outpatient setting using 0-degree and 30-degree endoscopes.  The entire nasal chambers, its recesses and the area behind the nasal cavity is examined in detail. When chronic sinus disease is suspected a CT scan of the Osteomeatal complex may be performed. The endoscopic findings are then correlated with the CT scan findings and further steps in the treatment of the condition contemplated. 

Endoscopic view of sinus infection