Well I agree mites sound most likely, you can check with a magnifying glass if you want to be sure. Mites can cause intense itchiness so worth treating. A course of ivermectin drops should sort them out. In the UK you can get them from the vets or online but i don't know about the US.
Sometime an attack of mites occur when a bunny is ill or rundown so it's worth investigating whether there is an underlying cause xx