The growing number of combined allergic diseases of the upper respiratory tract, in particular, allergic rhinitis (AR) and bronchial asthma (BA), substantiates the profound studies and the development of new approaches to the study of pathogenesis of the relation and interrelation between AR and BA, the relation prediction, early diagnosis and targeted treatment. In the review, the authors present actual data on the mechanisms of interrelation between AR and BA, the significance of AR in the manifestation of BA, the role of timely and pathogenetically substantiated therapy of the upper respiratory tract allergosis. The article describes the main pathogenetic links, relation and interrelation between AR and BA. Considerable attention has been paid to the specific features of treatment of the patients suffering AR and BA simultaneously, the advantage of allergen – specific immunotherapy (ASIT) over the other methods of respiratory system treatment has been substantiated. Under the conditions of arresting the upper respiratory tract pathology by an otorhinolaryngologist, and the lower respiratory tract pathology – by a pulmonologist, the article proves the necessity of continuous participation of a pulmonologist, otorhinolaryngologist and clinical allergologist in the treatment and diagnostics of this pathology.