The first treatment to help prevent serious allergic reactions to peanuts may be on the way. A company said Tuesday that its daily capsules of peanut powder helped children build tolerance in a major study.Millions of children are allergic to peanuts, and some may have life-threatening reactions if accidentally exposed to them. Doctors have been testing daily doses of peanut, contained in a capsule and sprinkled over food, as a way to prevent that by gradually getting them used to very small amounts.California-based Aimmune Therapeutics said 67 percent of kids who had its experimental treatment were able to tolerate the equivalent of roughly two peanuts at the end of the study, compared to only 4 percent of others given a dummy powder.But a big warning: Don't try this at home."It's potentially dangerous," said Dr. Stacie Jones, a University of Arkansas allergy specialist.