This is very hard for me to see however I am leaning to a bad shed right now. Everything shows on "white" snakes. If you want to know how your husbandry is, keep a primarily white snake. Every mistake shows. Humidity issues, dirt, mites etc.
Hopefully someone with better eyes takes a look also.
Last edited by JodanOrNoDan; 07-22-2016 at 03:19 PM.
The areas on his back look like substrate at some points. The head mark looks like a abrasion. Try using a moistened towel and let the snake crawl through it and see if there is any change.