R.
I have seen stranger things that turned out to be nothing. I would certainly continue to monitor and ask from time to time why to see if you get the same answer. I agree, if there's no pain not to worry, but the itch makes me wonder about allergies. Kids don't always grow out of allergies, but sometimes grow into them. If it's food, they usually itch in their mouths and with detergent or something it would be everywhere. You might call an allergist to ask some questions...it can't hurt. Sorry I couldn't be of more help but I'm sure it's nothing to worry about regardless.