Poor baby...
The food you are feeding is loaded with corn, which is a know allergen to dogs, so I would change his food to a good brand that doesn't have corn or by-products. You can give him some fish oil, I like Nordic Naturals for Pets, to his daily food. When my Roxy has the itches, I give her Children's Grape Fastmelt tabs. You can get the correct dose for your fella from your Vet. (Roxy is 4.5 lbs and can have 1/2 up to 3x a day).
Fabric softeners and the dies and fragrence in laundry detergent can cause skin issues too. So maybe change to the 'free' of 'stuff' kind.
Keep us posted!
You may have to see a derm vet
