What causes peanut allergies in children? Is it their family's allergy history? Or could it be exposure to peanuts in utero or during breastfeeding or some other factor (or combination of factors)? Researchers believe they may have discovered an important clue.
Infants between the ages of three and 15 months were enrolled in a study group; 503 of them were suspected of having an egg or milk allergy (which is a risk factor for peanut allergies) based on skin prick tests, but they had no known peanut allergy.
Of the 503 infants, 140 (27.8%) were found to have a strong sensitivity to peanuts based on blood tests that showed a peanut immunoglobulin E (igE) level of 5 kUA/L or more, indicating a strong likelihood that the child would develop a peanut allergy. The factor that best predicted this test result was the mother's consumption of peanuts two or more times a week during her pregnancy.
"Recent studies in children have estimted the prevalence of peanut allergy to be over 1% and approaching 2% indicating an epidemic," the study's authors wrote. "Peanut allergy is usually lifelong and can be fatal. These observations indicate a need for prevention measures. Our study has identified maternal consumption of peanut during pregnancy as a primary modifiable risk factor."
The study found other risk factors that cannot be modified: male gender, non-Caucasian race, and an igE response to milk and eggs. Consumption of peanuts during breastfeeding was not a significant predictor of the peanut igE response.
