probably what I call a 'dry scale'...sometimes a single scale or few scales will almost wrinkle up or dry out. it is quite common and could be caused by low humidity or other simple issues(I believe too dry air most of the time though). I have seen it on a few species, but more on balls than anything else. my albino black pastel has a couple on him...but they will usually go away with the shed...if not, they will by the next shed. think of it, as kinda a snake scab. it will more than likely go away after a shed or two. I would not worry about it!