People often look to soy if their child has a bad reaction to milk products. But what if the child is also allergic to soy? "Soy is one of the top eight food allergens in children," says Dr. Clifford Basset, an allergist based in New York. "Many kids will outgrow this food allergy by school-age years. Some may react to only one form of soybean, such as soy-milk, tofu or even edamame," Signs of a soy allergy range from a rash to swelling of the mouth and throat.