The Safety of Nasal Allergen Challenge Test Assessed in Lower Airways

The aim of the study was to assess the safety of nasal allergen challenge, and the use of certain parameters applied in assessing the condition of the respiratory system. We enrolled 30 patients diagnosed with allergy to common environmental allergens and 30 healthy controls. The safety of nasal challenge tests with an allergen was assessed by measuring the concentration of exhaled nitric oxide from the lower respiratory tract (eNO) and forced expiratory volume in one second (FEV1) in a spirometry test. In the early phase of the allergic reaction, extra-nasal symptoms were observed, namely cough and breathlessness. These measured symptoms using the VAS scale, were far more frequent in the patients diagnosed with perennial allergic rhinitis. The eNO and FEV1 values in the spirometry test did not show any statistically significant changes. No correlation was observed between the breathlessness and cough complaints to the eNO concentration levels (cough: r=0.019, p=0.921; breathlessness: r=-0.088, p=0.644) nor the FEV1 level (cough: r=0.002, p=0.983; breathlessness: r=-0.072, p=0.751) in the spirometry test. In the early phase of the allergic reaction, nasal allergen challenge do not cause any significant changes in the lower airways, as measured with the use of certain parameters applied in assessing the function of the lower airways' function.