Background  Eczema is one of the earliest and most common allergic diseases in infants. It is affected by many factors such as environment, heredity and immunity, and its pathogenesis has not been fully explained. Gal-9 and IL-33 have been reported to be closely related to bronchial asthma, allergic rhinitis, atopic dermatitis and other allergic diseases.

  Objective  To analyze the correlation between the levels of galectin-9 (Gal-9) and IL-33 in umbilical cord blood and the occurrence of eczema in 42d infants.

  Methods  A total of 114 newborns born in the Department of Obstetrics, Air Force Special Medical Center, from September 2020 to May 2021 were collected. Umbilical cord blood was collected immediately after birth to detect the levels of Gal-9 and IL-33. Outpatient follow-up was conducted 42d postnatal to investigate the incidence of infant eczema and maternal related information. According to the occurrence of eczema, subjects were divided into eczema group and non-eczema group. The correlation between the levels of cord blood Gal-9 and IL-33 and the occurrence of eczema in 42d infants was compared between the two groups. Logistic stepwise regression analysis was performed to analyze the risk factors of infant eczema. ROC curve of cord blood IL-33 was made.

  Results  There were 68 cases in the eczema group and 46 cases in the non-eczema group, and the prevalence rate of infant eczema was 59.6%. There was no significant difference between the two groups in terms of gender, gestational age, body length, birth weight, mode of delivery, feeding mode, family history of allergy, mother's age and maternal illness during pregnancy (P＞0.05). There was significant difference in whether the mother ate allergenic food during breastfeeding (P＜0.05). There was no significant difference in cord blood Gal-9 level between the two groups (P＞0.05), and the level of cord blood IL-33 in the eczema group was higher than that in the eczema group (31.03 15.42, 44.80 vs 22.42 12.25, 32.53, P＜0.05). Logistic stepwise regression analysis showed that high level of IL-33 in umbilical cord blood and sensitized diet of mothers during lactation were related risk factors affecting the occurrence of eczema in 42d infants (P＜0.05). ROC curve results of cord blood IL-33 showed that the AUC was 0.619 (95%CI: 0.516-0.722), with specificity of 82.6% and sensitivity of 41.2%.

  Conclusion  The correlation between umbilical cord blood Gal-9 level and 42d infant eczema is poor. The level of IL-33 in umbilical cord blood is correlated with the occurrence of infant eczema, and high level of IL-33 expression is a related risk factor for the occurrence of eczema, but its predictive value for early infant eczema is low.