Introduction
Asthma remains the most common chronic respiratory
disease in Canada, affecting approximately 10% of the
population [1]. Although asthma is often believed to be
a disorder localized to the lungs, current evidence indicates
that it may represent a component of systemic airway
disease involving the entire respiratory tract, and
this is supported by the fact that asthma frequently
coexists with other atopic disorders, particularly allergic
rhinitis [2].