With my son and his similar 3-4 SPD friends, there is no skin reaction to creams or shampoos, etc. They just don't like being touched unless you warn them or ask permission; basically being surprised is a no-no.
If the skin reacts to things, you may want to look into a skin allergy/dermatitis. There is also urticaria - reactions to touch, water, sun, etc. Do a quick search on urticaria and you'll see skin reacts like mosquito bites/welts, plus more. I hope this helps.
I am working with a child who is so sensitive to the feel of paper or anything like it with a dry feel, he says. He uses a transparency paper to put under
My son has refused to be fully potty trained since we started when he was a toddler. He jumps around and holds his belly in whenever he feels the sensation