Hi, I have this itchy bump (one) on my forearm that has moved 4 times. It is about the size of a pencil tip. It stays in one spot for about 2 weeks. Then it will go away and come back in a different spot. It only moves a couple of centimeters. All four spots have been within an area about the size of a quarter. The bump doesn't seem to have any color to it, it is just extremely itchy. Anyone have any idea what this could be? Thanks in advance!!