I Have What Feels Like Needles On The Surface Of

I have what feels like needles on the surface of my skin on my left and right forearm above and below my elbow? It slowly goes away when I apply an anti itch cream. There are no signs of poison ivy or sumac, no rashes and no visible signs of a problem on my skin. It comes and goes. It get worse when I itch it. Its been this way for many months. I've shaved my arms for the last several years. It started out in one spot months ago on my left arm and I itched it until it bled. Now there is a dark spot there.