my son had a strange rash like this once and our dr. said that he must have encountered a plant or other such thing that he was allergic to while playing. since a farm has thousands of things to get into we never did find out what the allergy was. the rash was head to toe and he looked like he had a massive sunburn. the dr. prescribed children's benedryl and the rash cleared right up. benedryl is over the counter and is dosed according to the package. try it out and see if you have the kind of luck we had with it.
my son has a rash all over his body that looks kind of like a heat rash but isn't red and doesnt itch what is it?