Sorry to hear about Max's spots...Does he have any tiny little bumps where the spots are? If so, it could be demodectic mange, which has to be vet treated. I have had a lot of experience with this type of mange, so if you have any further questions, just ask.

Otherwise I to would say allergies of some sort. Many dogs are allergic to even one flea bite and this can cause the symptoms you speak of.

Good luck...Jaquetta