This is past the point for home treatments.
This is very severe and needs to be seen by a Vet that specializes in reptiles. This is a severe infection. Could be caused by burns or scale rot. The scale rot in itself can be caused by burns or to wet and unsanitary conditions.
You really need to take the snake to be seen, this needs antibiotic shots AND ointment.
Meanwhile, tell us about the setup you keep this snake in. What kind of enclosure. What are the temperatures. What do you use to heat the enclosure. What do you use to control the output of heat (thermostat). What do you use to measure the temps. What is the humidity? What do you use as substrate?
How long have you had this snake, how long have you noticed this issue, has that snake ever eaten for you?
Could you post pictures of the setup?
I know that seems like a lot of questions, rather then answers. But to truly help you out, we need all this information.
The snake needs to be on paper towels and kept absolutely clean and sterile. The heat needs to be correct and controlled. This snake needs antibiotics (vet) before this turns toxic, if it hasn't already done so.
Good luck and let us know ..
