Local respiratory allergy (LRA) is a relevant pathological mechanism driving chronic airway disease in both atopic and non-atopic patients. This eosinophilic phenotype includes two entities: local allergic rhinitis (LAR) in non-atopic patients and dual allergic rhinitis (DAR) in atopic patients (coexistence of LAR and allergic rhinitis). Recent evidence indicates the existence of a bronchial counterpart of LAR (local allergic asthma), which emphasizes the pathophysiological links between the upper and lower airways and reinforces the united airways concept. In this article, we will review the clinical phenotype, pathophysiology, epidemiology, and natural evolution of LRA. Treatment options will be also addressed with a focus on the short-term and long-term beneficial effect of allergen immunotherapy (AIT) for LRA.