First, you should definitely take your snake to a vet. Usually, if you have to ask the question, the answer is yes. Even though there are a ton of really experienced people on the internet that can give you their opinion, it is impossible to properly diagnose a medical condition over the internet.

If it is scale rot I would say the following is your problem:

Quote Originally Posted by DrEwTiMe
In fact sometimes i have problems keeping it arond 60% so i have to spray the tank down sometimes 2-3 times day.
I would guess that that amount of spraying is making the subtrate damp which can cause scale rot.

If it's a burn, you might need to correct the way your heating pad is set up or check it for hot spots.

Either way, a vet can identify and fix your snakes problem far better than anyone here. This is an EXCELLENT site for advice and tips about all kinds of things, but when it comes to a possible medical condition with your animal, please see a professional.

Hope this helps, and good luck getting her better!

-adam