Household peanut consumption as a risk factor for the development of peanut allergy

It is thought that most children with peanut allergy react on first known oral exposure to peanut, such that recent data suggest the likely route of sensitization is through skin contact. In continuing attempts to better understand the route of sensitization, a survey of children with peanut allergy has recently been conducted.

In the current study, questionnaires were completed for children with peanut allergy, as well as two groups of controls: a group with egg allergy and a group without allergy. Among the questions asked were the level of maternal peanut consumption during pregnancy, breast-feeding, and the first year of life. Peanut consumption was also determined among all household members, allowing quantification of environmental household exposure to peanut.

A dose-response relationship was observed between environmental peanut exposure and the subsequent development of peanut allergy, which was strongest for peanut butter. Early oral exposure to peanut in infants with high environmental peanut exposure may have had a protective effect against the development of peanut allergy.

This study concludes that high levels of environmental exposure to peanut during infancy appear to promote sensitization, whereas low levels may be protective in atopic children. No effect of maternal peanut consumption during pregnancy or lactation is observed, supporting the hypothesis that peanut sensitization does occur as a result of environmental exposure.

Reference: Fox et al. 2009. Journal of Allergy & Clinical Immunology. Vol 123(2) pp. 417-23.