In a new study, published online Nov. 18 in the Journal of Allergy and Clinical Immunology, being exposed to peanut protein in house dust doubled the chance of having a peanut allergy. In children who have eczema, the risk of having peanut allergy was even higher.
Researcher Helen Brough, from the department of pediatric allergy at King's College London, U.K., and colleagues note that eczema "is often cited as the first step in the allergic march."
How peanut allergies develop is not yet clear, says Carla M. Davis, MD, a specialist in children's allergies at Texas Children's Hospital in Houston. There is still plenty of controversy in the field, she says.
For instance, some researchers are testing a "patch" for people who already have a peanut allergy that would introduce the allergen through the skin to build tolerance. That seems to contradict the findings in this study, she says.
The researchers found out how much peanut protein infants were exposed to by measuring dust vacuumed from the patients' living rooms.
The researchers studied 359 children who had a high risk of developing a peanut allergy because they were already allergic to cow's milk or eggs, or had moderate or severe levels of eczema and had allergies to those foods.
"This study adds to the growing body of evidence that exposure to peanut via a damaged skin barrier [as in ezcema] may increase the risk of peanut allergy,” Brough says in a news release.
Several co-authors report receiving support from the Immune Tolerance Network, the Wellcome Trust Intermediate Clinical Fellowship, DBV Technologies, Dyax, and Hycor Biomedical. One co-author is a minority stockholder in Allertein and Mastcell Pharmaceuticals. Another has stock options with DBV Technologies. Several co-authors report receiving royalties from UptoDate. One co-author is a member of the Scientific Advisory Board for DBV Technologies. Several co-authors report consultancy arrangements or having received payments for lectures from one or more of the following companies or groups: Novartis, Abbott Laboratories, Dow AgroSciences, McNeill Nutritionals, Merck, Schering Plough, GLC Research, ExploraMed Development, Regeneron Pharmaceuticals; Unilever; Allertein Therapeutics; Danone Research Institute; Anaphalaxis Campaign; and the National Peanut Board. ThermoFisher Scientific, UCB, Pfizer, Sodilac, Nestle Nutrition, and GlaxoSmithKline.