Purpose of review: For the present article we collected and reviewed the more relevant experimental results concerning the asthma-rhinitis link in allergic diseases, published since January 2002.
Recent findings: During the last 2 years, particular attention has been devoted to the behaviour of the immune response in the two compartments of the airways. The recent experimental data, mainly obtained with specific nasal or bronchial allergen challenges, have confirmed that the link between the nose and the bronchi is bidirectional, and that a systemic cross-talk occurs. Furthermore, the pathogenic role of paranasal sinus infections in respiratory allergy has been better elucidated. It was shown that, in sinusitis, a T helper type 2 polarization exists, which can be reverted by proper therapy. On the other hand, despite the abundant experimental evidence, our view of the united airways is still not complete, and several points need to be developed.
Summary: The new findings on the asthma-rhinitis link have confirmed the current pathogenic view of respiratory allergy. These findings have important implications from a therapeutic point of view, and therefore encourage and promote the search for novel integrated treatment strategies.