Rhinosinusitis (RS) refers to the presence of inflammation in the paranasal sinuses mucosa (i.e., the lining of the sinuses) and the contiguous mucosa of the nasal passages. When it is present for less than one month, the condition is termed acute rhinosinusitis. If the inflammation is present for more than 12 weeks, then chronic rhinosinusitis is present. If the duration is between 4 and 12 weeks, the rhinosinusitis should be considered subacute. Recently, chronic rhinosinusitis (CRS) has been further classified as CRS with nasal polyps and CRS without nasal polyps.
The causes of RS are diverse, and often it is not possible to precisely identify a specific cause.
This video segment illustrates aspiration of mucus from the middle meatus for culture..
Furthermore, RS may mimic other conditions, including isolated inflammation of the nasal lining (rhinitis). Precise diagnosis includes a detailed history, examination, specific testing and imaging studies, and serves as the foundation for appropriate treatment.
Rhinosinusitis has been classified based upon its duration:
- Acute rhinosinusitis: duration of less than 4 weeks
- Subacute rhinosinusitis (duration of 4-12 weeks)
- Chronic rhinosinusitis (duration of greater than 12 weeks)
- Acute exacerbation of chronic rhinosinusitis (exacerbation of chronic rhinosinusitis, with return to baseline symptoms after appropriate treatment)