Would benadryl help with a viral rash?

Maybe: If the rash is itchy it may help the itch, if it is itchy, but the rash won't go away. It is important to realize that scarlet fever is a rash caused by strep & needs to be treated w/antibiotics. A rash from scarlet fever can feel like sandpaper and it's itchy in some folks. Please be sure to get checked for strep to be safe. A strep rash can come & go too! You can have it without a sore throat.