I think it’s the same thing. At least, I’ve always considered it the same thing. I think when the whole digit appears red and swollen it’s actually some inflammation in the joint. Feel around and I think you will find that there is pain in the joint when you press on it. The itchiness comes when the sore is healing, but mine will remain red and swollen for a couple weeks until this happens. I’m not a doctor, I’m just speaking from my own experience. Keep it warm, get some warmer boots, wear foot warmers when you are going outside for a while. I think soaking it in some warm, not hot water will also speed the healing. Show it to a doctor if you’re concerned.