rash can be caused by a food allergy. even though your son's diet hasn't changed doesn't mean he can't develop a food allergy. or maybe he is now eating more of something he ate little of before. so to be sure write down what he ate prior to his rash. if you think there is a link between something he ate and the rash let his doctor know. here are common food allergies. good luck!
4 yr old son has a rash that comes and goes no other symptoms dr do not know what it is. need help please. no new detergents or foods nothing has changed in the environment he lives in sometimes it itches sometimes it does not. er drs say its a viral thing because they don't know.