My 3 year old son developed a rash that s raised, almost blister looking but i don t see or feel any fluid in them. Kind of a welt like rash. It s on hit butt cheeks, back of thighs most thickly. But also on the front of his legs, knees and moving to the calves. Tried a benadryl cream for kids and am thinking of doing an oatmeal bath next. I can t find any pictures online that really match this 100%. Thinking about a dr visit but also thinking i should try the bath, change his bed clothes and see what tomorrow brings. Any advice would be helpful