Serum Vitamin Profiles in Pediatric Eczema, Atopic Dermatitis, and Urticaria

Background: Eczema, atopic dermatitis, and urticaria are common pediatric inflammatory skin diseases, but serum vitamin profiles across these diseases remain poorly characterized. Objectives: To compare demographic characteristics, serum vitamin levels, and vitamin insufficiency rates among children with these diseases, and to identify independent factors associated with disease presence. Methods: This retrospective study included 504 children: 43 with eczema, 43 with atopic dermatitis, 40 with urticaria, and 378 healthy controls. Serum levels of nine vitamins were measured by electrochemical assays. Univariable and multivariable logistic regression analyses were used to identify associated factors with false discovery rate correction. Propensity score matching based on age and sex was additionally performed for each disease-control comparison, followed by matched regression analyses. An exploratory nomogram was developed and evaluated. Results: The mean age of the cohort was 6.26 years, and 50.2% were male. Vitamin B9 insufficiency was the most prominent abnormality, occurring more frequently in the overall disease group than in controls (17.5% vs. 0.3%, p < 0.001). Vitamin D insufficiency appeared more frequently in the urticaria group than in controls (42.5% vs. 28.3%, p = 0.062). In multivariable analyses after PSM, vitamin B9 insufficiency and lower vitamin B6 levels remained independently associated with all three diseases. Conclusions: Pediatric inflammatory skin diseases exhibited distinct vitamin profiles relative to healthy controls, with vitamin B9 insufficiency emerging as a common feature across eczema, atopic dermatitis, and urticaria.