Abstract: Objective·To investigate the potential risk factors of recurrent wheezing in preschool children. Methods·A casecontrol study was conducted in 370 children with wheezing admitted to the Department of Respiratory Medicine in a specialized hospital for children in Shanghai from December 2019 to December 2020. The children were preschool children aged 3-6 years.According to the frequency of wheezing, pediatric patients were divided into occasional wheezing group（1-2 attacks per year） and recurrent wheezing group（≥3 attacks per year）. The face-to-face questionnaire was performed to the parents responsing for basic information and recurrent wheezing risk factors including the children age, gender, gestational age, birth weight, history of eczema,history of allergic rhinitis, history of food allergy, history of inhalational pollen allergy, history of bronchiolitis, maternal age,production mode, feeding pattern, history of parental asthma, resident area（city/village）, passive smoking, history of pet contact,seasonal factors, etc. Univariate analysis was used to compare risk factors of recurrent wheezing between the two groups. Logistic regression analysis was used to analyze the independent risk factors associated with recurrent wheezing. Results·Three hundred and seventy cases were enrolled, including 204 cases（55.14%） in the occasional wheezing group and 166 cases（44.86%） in the recurrent wheezing group. A total of 10 risk factors were determined for recurrent wheezing, which included children’s age（χ~2=36.608, P=0.000）, gender（χ~2=4.290, P=0.038）, eczema（χ~2=6.250, P=0.012）, allergic rhinitis（χ~2=10.787, P=0.001）, inhaling pollen（χ~2=8.868, P=0.003）, history of bron chiolitis（χ~2=27.898, P=0.000）, gestational age（χ~2=5.141, P=0.023）, feeding pattern（χ~2=4.316,P=0.038）, parental asthma history（χ~2=5.050, P=0.025） and resident area（χ~2=31.013, P=0.000）. The Logistic regression showed that allergic rhinitis（OR=4.759, 95%CI 1.665-13.603）, bronchiolitis（OR=12.113, 95%CI 5.686-25.802）, premature birth（OR=3.092,95%CI 1.120-8.539） and living in city（OR=2.395, 95%CI 1.326-4.324） were the independent risk factors of recurrent wheezing.Conclusion·The independent risk factors for recurrent wheezing in preschoolers include allergic rhinitis, bronchiolitis, premature birth and living in city.

Key words: wheezing, recurrent, risk factor, preschool child