C.W.
Hi L.
Sounds like it could be a food allergy- most food allergies first appear on the face area- and looks like a red rosey rash- but I would suspect it is from the detergents you are using for laundry of his cloths and bed sheets etc- there are chemicals in all detergents bought at the store and these chemicals leave a residue in the fabric- no matter how many times they are rinsed. PM me and I can send yu to a link that has some products that are eco friendly and chemical free-with other lotions etc that will help his skin. I am not trying to sell any products, just letting you know of the products I use in my home that have helped us with rashes and other issues.
good luck
blessings