It looks like a problem though. At this point, that area could be an injury, a small burn, or the beginning of scale rot. I would use a little plain neosporin (no painkiller) to make sure your snake doesn't get an infection. I would also switch to a paper towel substrate for a little while. Check husbandry, make sure the snake can't get burned on your UTH. If things get worse go to the vet. If things remain stable, the problem should go away next shed.

David