Need some help/advice

So this is the second time my babies skin has done this to the touch it’s very rough and as you can tell he has been trying to scratch himself on the right of his stomach but as i got him out of the bath it looks almost as if it’s a rash he’s about four months old I think he may be due to the soap for his bath i use on him but I’m not sure and was wondering when to bring him in? I’m not sure if this is just like eczema or if it’s a rash any thoughts?