I still have the suspicion of something to do with blister disease or something turned septic ..

Of course I could be WAY off base here. It seems as if the blood vessels are seeping under the skin for whichever reason. And that looks like a blister on the back.

What is causing all that ? That is the question

Dr. Del had a awesome idea, see if you could email a reptile vet in the US. Some are super nice and helpful, they cannot give you a diagnoses over the internet, but they can point you in the right direction.

The poor thing