Are the scales clear or are they brown? If the scales are clear then he's probably having a bad shed (very dry) and the scales are flaking off 1 at a time. If this is the case dump the water dish into the substrate and fill it back up again as well as spray the snake down with water.
If the scales are brown and falling off then it's probably scale rot. Minor cases can be treated by keeping the snake warm, dry and applying polysporin to the affected areas. If it's a severe case then you'll have to use an antibiotic as well as polysporin. If you have to go that route go with Fortaz (ceftazidime) and not Baytril (I hate Baytril).