Bring the snake to a vet immediately. That looks pretty serious, and i would be worried about things getting worse, and causing infection. If you do not, its very likely that the snake could die if it is not properly taken care of.
You have to be absolutely dilligent in keeping that enclosure clean, and AT the PROPER temperatures. and DRY ( Humidity is OK, WET Substrate is NOT)
What are you using to heat the previous enclosure? and what were you keeping the snake on? Can you take photos?