Betta with wierd patches?

i've got a blue crowntail male betta named zeke. on teh top of his back just in front of his dorsal he has these patches of missing scales??? or maybe they are just turning white? not sure. 2 patches, one is the size of a pencil eraser, the other is smaller. but they are getting bigger and spreading down his side. it is not fungus, cuz its not furry. definitely NOT ich, becuz they are patches NOT grains of salt. i have seen both fungus and ich before but i have never seen this. he is acting normal, eating, swimming, no clamped fins (yet). and their is no aggressiveness going on so they didn't get ripped off by another fish. all i have in their with him are guppies and platies and both are very peaceful. they don't mess with him, he doesn't mess with them. if anybody could help me that would be great!