RAST test came back normal except for mild for soy. GI Dr. wasn't concerned and no suggestions were made to limit or remove soy from my sons diet. My son has had ezcema and consistently has mushy BMs.
Alot of kids on the spectrum have sensitivity to soy. I read some articles where some had erosion of the esophagus from soy due to the allergy of soy. Keep him off soy if he does have even a mild soy allergy. You can replace soy with almond, which is more healthier and has some omega properties. I've done great research on foods and sensitivities. My son has food allergies, I've had him on a special nutritional support plan for about 10 years now.