Suggest Treatment For Itchy Bruise On The Wrists

Out of nowhere the inside of my left wrist started to itch, I thought I had gotten an insect bite, then the vein on my wrist that runs into my hand (about an inch in length) swelled and was tender for about 30 min, then turned into a bruise along that same portion of the vein. There are now a few veins in my hand that are very visible in a V shape with a small blue swollen spot at bottom of the V . All still tender to the touch.