Study on the relationship between fractional exhaled nitric oxide level and asthma predictive index in recurrent wheezing infants under 3 years of age

Abstract

Objective To investigate the relationship between fractional exhaled nitric oxide (FENO) and asthma predictive index (API) in infants under 3 years of age. Methods Totally 62 cases (under 3 years of age) who were hospitalized from June 2015 to June 2016 and had more than 3 times wheezing over the past year were enrolled in this study. They were divided into two groups according to API: API positive group with 37 cases and API negative group with 25 cases. FENO levels and peripheral blood eosinophil levels were detected and skin prick allergy test (inhalation and ingestion of allergens)was done in all selected children, did skin prick allergy test (inhalation and ingestion of allergens), simultaneous detected peripheral blood eosinophil levels. The parents of the children were investigated by questionnaire to know the children′ history about atopic dermatitis (such as urticaria, eczema, etc) and parents′ wheezing history. Above information was recorded and statistics analysis was made. Results There were no significant differences between two groups in atopic dermatitis inhalation and ingestion of allergens (P <0.01 or <0.05). The level of FENO in API positive group and API negative group was (16.70 ± 11.07), (13.52 ± 11.01) ppb (1 ppb=1 × 10- 9 mol/L), and there was significant difference (P<0.01). Conclusions There are associations between FENO and API, and they have good reference value in predicting the risk of asthma. Key words: Infants; Recurrent wheezing; Fractional exhaled nitric oxide; Asthma predictive index