Food allergy risk up for children born in the fall

(HealthDay) -- Children born in the fall have an increased risk of food allergy, with a significantly increased risk seen only for Caucasians and those with eczema, according to a study published online April 19 in Allergy.

In an effort to investigate the mechanisms by which season of birth impacts on food allergy risk, Corinne A. Keet, M.D., of the Johns Hopkins School of Medicine in Baltimore, and associates used data from 5,862 children in the National Health and Nutrition Examination Survey (NHANES) III and 1,514 children with food allergies from the Johns Hopkins Pediatric Allergy Clinic (JHPAC).

The researchers found that, in both the NHANES and JHPAC populations, fall births were more common among children with food allergies (odds ratio [OR], 1.91 and 1.31, respectively). There was a significant interaction between ethnicity and season (OR, 2.34; 95 percent confidence interval [CI], 1.43 to 3.83 for Caucasians; and OR, 1.19; 95 percent CI, 0.77 to 1.86 for non-Caucasians; P = 0.04). There was also a significant interaction between eczema and season (OR, 1.47 for those with eczema and 1.00 for those without eczema; P = 0.002).

"Fall birth is associated with increased risk of food allergy, and this risk is greatest among those most likely to have seasonal variation in vitamin D during infancy (Caucasians) and those at risk for skin barrier dysfunction (subjects with a history of eczema), suggesting that vitamin D and the skin barrier may be implicated in seasonal associations with food allergy," the authors write.