How is the diagnosis of sinusitis made?

The symptoms of sinusitis are not unique to the disease itself. Other disease processes can mimic sinusitis including the common cold, allergies, migraine headache, chronic daily headache, myofascial pain, temporomandibular joint or jaw pain, rhinitis medicamentosa, and even sleep apnea. Therefore an accurate diagnosis requires a thorough history and physical examination. This will document the timing, duration, severity of the symptoms, what interventions have previously been performed and the success of each.

“Nasal endoscopy” is also used to make the diagnosis of sinusitis. This procedure involves passing a fiber-optic telescope, or "endoscope," into the nose and examining the interior of the nasal cavity. It is performed in the clinic setting with mild topical nasal anesthetic. The endoscope provides excellent lighting, magnification, and visualization of the mucosal lining around the sinus openings into the nasal cavity. This allows the Otolaryngologist to more precisely identify anatomic abnormalities that may be contributing to sinus infections, or monitor a patient’s response to therapy.

While nasal endoscopy plays a major role in the diagnosis of sinusitis, this procedure can only give information about the openings of the sinuses (unless the patient has had previous surgery to widen the natural openings). Therefore another tool, called computerized tomography or a CT scan, is used to visualize the sinus interior. The CT scan provides information about swelling within the sinuses and also provides a road map of sinus anatomy should surgery be necessary.

Each of these modalities (i.e., history and physical examination, nasal endoscopy, and CT scan) plays an important role in the diagnosis of sinusitis. Any single study in isolation is of much less value, while the use of all four modalities is most effective in making an accurate diagnosis and treatment plan.