Objective To investigate the prevalence of food allergy, asthma, atopic dermatitis, and allergic rhinitis among children aged 0‒6 in Minhang District of Shanghai, and to analyze the associations of sociodemographic characteristics, neonatal factors and dietary related factors with these allergic diseases, so as to provide epidemiological evidence for the development of regional prevention strategies.

Methods From June to October 2025, a multi-stage stratified cluster random sampling method was used to enroll children aged 0‒6. The disease status was assessed in accordance with the criteria of the International Study of Asthma and Allergies in Childhood. Relevant information was collected using structured questionnaires and food frequency questionnaires. Descriptive statistics and multivariate logistic regression analyses were applied to analyze the influencing factors.

Results Among the 2 145 children aged 0‒6, the mean age was (4.25±1.52) years. The prevalence rates of food allergy, asthma, atopic dermatitis and allergic rhinitis were 17.25%, 11.05%, 40.51%, 19.07% respectively. Comorbidity was prominent, with the pairwise comorbidity rate ranging from 3.78% to 11.38%. The prevalence of allergic diseases was higher among children aged 3‒6 than among those aged <3, and was significantly higher in boys than in girls (all P<0.05). Intake of refined grains ≥1 time·d^-1 was associated with an increased risk of food allergy (aOR=5.72, 95%CI: 1.20‒27.27) and atopic dermatitis (aOR=2.64, 95%CI: 1.01‒6.92). Conversely, consumption of coarse grains (3‒6 times·week^-1), melon and solanaceous vegetables (≥1 time·d^-1), and dairy products (3‒6 times·week^-1) was associated with reduced risks of different allergic diseases, with aORs of 0.47 (95%CI: 0.25‒0.90), 0.43 (95%CI: 0.22‒0.85), and 0.40 (95%CI: 0.19‒0.87), respectively. Intake of fruits, eggs, and nuts at 3‒6 times·week^-1 was each associated with a reduced risk of food allergy, with aORs of 0.19 (95%CI: 0.04‒0.93), 0.34 (95%CI: 0.15‒0.78), and 0.52 (95%CI: 0.28‒0.97), respectively.

Conclusion The prevalence of food allergy, asthma, atopic dermatitis, and allergic rhinitis is relatively high among children aged 0‒6 in Minhang District of Shanghai. Excessive intake of refined grains is associated with an elevated risk of allergic diseases, whereas a diet rich in coarse grains and vegetables showed a negative association. It is recommended to introduce eggs and nuts at appropriate time points during infancy and to promote the consumption of whole grains and vegetables among preschool-aged children.