The document discusses the relationship between allergic rhinitis and asthma and how they are united through epithelial cells. Epithelial cells represent the first barrier of the upper and lower respiratory tracts, making them a logical target for integrated therapeutic approaches. The review discusses how rhinosinusitis can be a co-morbid condition, precipitating/triggering condition, or epiphenomenon that is an integrated part of the overall disease. It calls for a better understanding and more pragmatic/cost-effective approaches to diagnosis and long-term management.