Rhinosinusitis and asthma: the missing link

Purpose of review Disease of the nose and sinuses is the most common comorbidity associated with asthma. Rhinitis, sinusitis and asthma may represent part of one disease process with manifestations at different sites. The purpose of this review is to highlight significant new findings on the epidemiological and pathophysiological link between the upper and lower airway. Finally, we will review recent data assessing the impact of treating sinonasal disease on both the development of asthma and asthma control. Recent findings Studies illustrate that rhinitis is very common in asthma, and associated with worse asthma control. Rhinitis typically precedes the development of asthma. Even in patients with rhinitis without asthma, there is evidence of subclinical change in the lower airways as measured by physiological changes and the presence of inflammatory mediators. There is much interest on the impact of treating allergic rhinitis on the development of asthma. Summary Rhinitis, sinusitis and asthma are likely part of one disease process. Treatment of established rhinitis may have some impact on measures of airway obstruction, but an effect on lower airway inflammation is yet to be established. Prospective studies are required to determine whether treatment of rhinitis can prevent the development of asthma, or decrease airway inflammation to improve asthma outcomes in those with established asthma or both.