Are Rhinitis and Asthma Just One Disease Affecting Different Parts of the Respiratory Tract?

Both allergic rhinitis and chronic rhinosinusitis with or without nasal polyps have important factors in common with asthma. They are often present simultaneously, they have similar pathogenesis processes, and they have synergistic effects on the clinical manifestations. There are also important considerations regarding the common treatment of these pathologies. Taking all these into account, it is possible to place these diseases under the “united airway disease” umbrella. However, matters such as embryologic origins, anatomy and function of the upper and lower airways, as well as cases where the aforementioned pathologies can be observed independently and have different treatment responses, make up reasonable counterarguments for the “united airway disease”. This narrative review attempts to put all these factors into perspective for a slightly better understanding of the complexity of this topic. We will take into consideration factors such as epidemiological data, pathogenesis and pathology, clinical considerations, and the benefits of a common treatment.