How to Diagnose and Treat Local Allergic Rhinitis: A Challenge for Clinicians.

Chronic rhinitis is a very common disease that can be divided in various phenotypes. Historically, the condition has been classified into the allergic rhinitis (AR) and non-allergic non-infectious rhinitis (NAR) forms, based on the results of the classical biomarkers of atopy: skin prick test and serum allergen-specific IgE However, this classification does not reflect the complexity of the rhinitis syndrome, as illustrated by the existence of non-atopic rhinitis patients who display a nasal reactivity to environmental allergens. This new phenotype has been termed local allergic rhinitis (LAR) and can be only recognized if an additional test such as the nasal allergen challenge (NAC) is integrated in the diagnostic algorithm for chronic rhinitis. Recent data shows that the NAC is a very safe and reliable technique ready for the clinical practice. LAR is a differentiated rhinitis phenotype which often commences during childhood and quickly progresses towards a clinical worsening and the association of comorbidities in other mucosal organs. Recent evidence supports the existence of a bronchial counterpart of LAR (local allergic asthma), which highlights the pathophysiological links between the upper and lower airways and reinforces the united airways concept. Importantly, several controlled studies have demonstrated the ability of allergen immunotherapy to control LAR symptoms while the therapy is being administered. This review emphasizes the need to implement the NAC in the clinical practice in order to facilitate the recognition of LAR patients, allowing for an early prescription of specific therapies with disease-modifying potential.