1P-S1-4

THE LINK BETWEEN RHINITIS AND ASTHMA

De-Yun Wang, MD, PhD.

Department of Otolaryngology, The National University of Singapore

Allergic rhinitis represents a global health problem, affecting 10 to 25 % of the world population. Although it is not usually a severe disease, it alters significantly the social life of patients and affects school learning performance and work productivity. Rhinitis and asthma are very common co-morbidities suggesting the concept of "one airway, one disease" because rhinitis and asthma are linked by epidemiologic, pathologic and physiologic characteristics and by a common therapeutic approach. Many cross-sectional studies have demonstrated that patients with rhinitis appear to be more likely to develop asthma. During the past ten years, there is an extensive research activity directed towards the basic biology and immunological functions of the components that constitute the framework of the airway mucosal immune system. The structure of the airways mucosa presents similarities between the nose and the bronchi and both are characterized by a pseudostratified epithelium with columnar, ciliated cells resting on a basement membrane. The recent progress achieved in the cellular and molecular biology of airways diseases have clearly documented that inflammation plays a critical role in the pathogenesis of rhinitis and asthma. A growing number of study show that the inflammation of nasal and bronchial mucosa is sustained by a similar inflammatory infiltrate, which is represented by eosinophils, mast cells, T-lymphocytes and cells of the monocytic lineage. The same pro-inflammatory mediators (histamine, Cys-LT), Th2 cytokines (IL-4, IL-5, IL-13 and GM-CSF), chemokines (RANTES and eotaxin) and adhesion molecules appear to be involved in nasal and bronchial inflammation of patients with rhinitis and asthma. Therefore, it has been recommended by the recent ARIA guidelines that patients with persistent allergic rhinitis should be evaluated for asthma, and patients with asthma should be evaluated for rhinitis. A strategy combining the treatment of both the upper and lower airway disease in terms of efficacy and safety appears to be optimal.