All-round examinations of 484 patients with acute stenoses of the upper respiratory tract revealed two clinico-pathogenetic varieties of the disease: allergic (48.7%) and infectious-inflammatory (51.3%). All the patients demonstrated high allergy whatever the disease variety. The most important laboratory indicators of allergy were as follows: the rise of the index of eosinophilia, of the count of rosette-forming eosinophils in nasal secretion, a high content of total IgE and of allergen-specific IgE-antibodies, attesting to the presence of atopic allergy. These changes were more pronounced in the disease of allergic genesis. The differences in the pathogenesis should be necessarily taken into consideration during treatment administration. In the allergic disease variety, the main approach consists in administration of antihistaminic drugs in addition to the routine treatment measures, whereas in the infectious inflammatory variety, the treatment should also include antiviral agents.