ABSTRACT
During the past century, practicing clinicians have frequently observed that chronic rhinitis, sinusitis, and asthma coexist in the same patients. Despite a wealth of data supporting an association between the upper and lower airways, not until recently has strong data emerged which suggests that the pathogenesis of the three conditions is quite similar, and that treatment of upper airway disorders may lead to improvements in asthma. Although much of the emphasis in the experimental literature has been directed toward atopic airway disease, there is now a growing realization that nonallergic rhinitis, sinusitis, and asthma are causes of considerable morbidity and deserve clinical investigation. In this chapter, data from a variety of epidemiologic, laboratory, and clinical studies will be highlighted to help clarify our understanding of this complex and important relationship.
