Blister Disease or something else?

My male ball python, Reshmar, has what kind of looks like burn marks on top of his back. Only on the ridge of his back, and nowhere else on his body. I don't think it is burn marks, because there is nowhere in the cage for that to happen to him. My other snake doesn't have this kind of problem at all.

He doesn't act like it is painful when I touch it, but I really don't think it is healthy...so I want to find a way to fix it. Anyone have any idea what this could be? Will I need a Vet visit for sure, or could it be blister disease, and I should just clean my tank really well for him?

Before people ask, the temperature gradient is good, it is a 4 foot cage, and he is probably about a year old now. Maybe a little less.

EDIT: I should add, there is no way the problem could be caused by a rodent gnawing on him. I watch him when I feed him live mice to make sure they don't chew on him.

EDIT 2: Scale rot? Oh man...

personally i haven't heard of this... hopefully someone with more experience will chime in.

but... may i ask... what exactly is a good temp gradient? how are you heating? that's a big "cage" for a young snake... is it a tank or ???

does he soak? how big is the water dish? how often do you change/clean the water and dish?

Sounds kind of like scale rot to me...

I would recommend putting him on some newspaper if you have something else as substrate at the moment. What is his temp. gradient(warm side temp/cool side temp?) I'll also ask: you mention another snake... they aren't kept together are they?

Also: do you have a camera? some pics might help someone try to diagnose what it may be. It's difficult to diagnose things over the internet, so I would schedule an appointment with a herp vet ASAP.