The Impact of Upper Airway Allergic Inflammation on Asthma
Pathophysiological Links Between Allergic Rhinitis and Asthma
Prof. W.J. Fokkens and Dr. C.M. van Drunen
C. Warren Bierman presented on behalf of Wytski Fokkens.
The structural and functional differences within the respiratory tract have been the basis for separating the airway into upper and lower entities. Despite this distinction, similar mechanisms are now thought to underline asthma and allergic rhinitis (AR), two of the most common components of airway disease in the Western world. The implications are important as both asthma and AR have a high prevalence in adults and children and are associated with substantial health care costs and a large impact on quality of life. The “ARIA” document (Allergic Rhinitis and its Impact on Asthma) stresses an integrated approach in the treatment of both diseases. Treatment of AR may affect concomitant asthma leading to significant improvements in health, quality of life, and a reduction of costs to society. The cost reduction is not only related to a reduction in the use of medication, but also related to a reduction in lost working days.
Although both asthma and AR are associated with atopy and often occur together, it is still unclear why some allergic patients develop only asthma and others only rhinitis. Also the reason for the large variety in clinical expression that can be seen in patients is not known. Multiple factors have been shown to play a role, including genetic predisposition, environmental factors, and local and systemic inflammatory processes. However, the extent to which these factors contribute to the manifestation of allergic airway diseases still remains to be elucidated.
Despite some of the anatomical differences between the lower and upper airways it seems that there is much commonality. Not only from the scientific point of view, relating to the similarities in the allergic infiltrate in nasal and bronchial mucosa, but also from the clinical point of view where treatment of one disease also improves the other. An important step forward would be an understanding of the molecular mechanism that links the upper and lower airways. Although this matter is far from resolved, most data point towards a systemic link between upper and lower airways, involving bloodstream and bone marrow. This presentation provides an overview of this emerging field and highlights some of the more recent data.
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