The state of intranasal structures was compared in patients with EOM and AR and EOM without AR. It was determined that the most likely cause of the violation of the protective function of the nasal mucosa in patients with EOM and AR is serous inflammation, manifested by a number of structural and functional changes. Structural changes are characterized by de-epithelialization of the mucous membrane in the acute phase, an increase in the number of goblet cells, a change in the viscosity of the medium, and a change in the pH of the medium. Each of the described processes ultimately leads to a slowdown in mucociliary transport, which occurs in the patients with EOM and AR that we examined. Thus, the curvature of the nasal septum and other features of the architectonics of intranasal structures in patients with EOM to a lesser extent than in patients with EOM and AR affect the development of the disease.