Sinusitis is a term that refers to inflammation of the paranasal sinuses, a major health problem in the United States that substantially affects up to 1 in 7 adults. The effects of sinusitis can be disabling in many respects, and have been shown to affect quality of life, productivity, & finances.

The cause of sinusitis can be infectious or noninfectious. Because the nose is almost always involved in inflammatory conditions of the sinuses, the term rhinosinusitis is sometimes used interchangeably with sinusitis.

Rhinosinusitis can be categorized in many different ways. One such way is by the duration of inflammation and symptoms:

• Acute rhinosinusitisis defined as up to 4 continuous weeks of purulent nasal drainage (containing pus) that occurs in the setting of nasal obstruction and/or facial pain or pressure. It is often preceded by an upper respiratory infection otherwise known as the common cold. Most infectious causes of rhinosinusitis are extensions of the viral infection causing the common cold; these typically resolve without medical intervention. However, a minority of these cases progress to bacterial rhinosinusitis and may require medical intervention. The symptoms may be similar for both viral and bacterial infections. Viral rhinosinusitis is suspected when symptoms have been present for less than 10 days and are not worsening. However, if symptoms last 10 days or longer after an upper respiratory infection, or worsen after an initial improvement within a 10-day period acute bacterial rhinosinusitis is suspected.
• Recurrent acute rhinosinusitis is defined as 4 or more episodes of acute sinusitis per year without signs or symptoms of infection between episodes.
• Subacute rhinosinusitis is defined as symptoms for more than 4 continuous weeks but less than 12 weeks
• Chronic rhinosinusitis is defined as 12 or more continuous weeks of two or more of the following symptoms:
  • purulent (pus containing) nasal drainage
  • nasal obstruction
  • facial pain/pressure/fullness
  • decreased sense of smell

In addition, to these symptoms, your doctor may see evidence of sinus or nasal inflammation, purulent (pus containing) mucus, or nasal polyps on examination or with imaging studies such as a CAT scan.

There are numerous causes of chronic rhinosinusitis including infectious (viral, bacterial, and fungal), allergic, anatomic, mucociliary (a problem with the natural clearance mechanism of the sinuses such as in cystic fibrosis or ciliary dyskinesia), and systemic disorders. Chronic rhinosinusitis is typically further subdivided into categories of patients with and without polyps.