Try to remember that next time the urges are bad. 1. You don't deserve the pain and injuries. 2. Even if SI helps, it helps only a little bit for a very short time. 3. Injuries suck.
But itching sucks. Talcum powder with menthol can help, but I'm not sure if using talcum powder on a wound (even if it's a closed burn) is a good idea because it dries out the skin.
I hope this is again the start of a long SI-free streak.