Hi,
I would look for other signs of mites before going that far - look in his heat pits and around his eyes as well as wiping him down with a damp paper towel.
Look for dark spots on the papertowel that spread a rust coloured spot around them if you leave it for five minutes.
As for the scale I would just keep an eye on it for now to see if it changes and see if it goes away with his next shed.
What kind of substrate are you using?
dr del