Strange White color around scales on head

[SilasBannook]

I have been watching two of my snakes and one of my wandering and one of my radixes have both developed this odd white coloration on some of the scales at the top of their head. Attached are pictures. I have tried to wipe it off to no effect. Sir Farts Alot (my boy named that female wandering garter) has been enjoying lots of time in the water bowl so I am not thinking it is a weird precursor to a shed. I did read on some threads about a blistering disease. I keep the substrate quite dry but a large water bowl is available for both snakes to ensure they get enough moisture for their skin/scales. Should I use Hibicleanse as discussed for the blistering disease? I would appreciate input from anyone that has seen this. Both snakes are in separate terrariums with other snakes so I do have a concern if this is contagious. Neither snake is eating much but that may be due to it being the time they should be brumating. They both are behaving normally. Thanks for the input.

Sir Farts Alot white scale pic3.jpgSir Farts Alot white scale pic2.jpgBig Mama white scale issue pic1a.jpg