Yes, I get this. And can flip out really badly sometimes trying to deal with it. It can go for hours, the sensations are in various locations, and I haven't figured out any pattern for when it happens. We haven't totally pinpointed what is happening. Is it a tactile hallucination or possibly OCD thoughts gone out of control? I lean towards the former just because there are times I'm not thinking about bugs at all and it will start. Whatever it is, I wish I could stick to swatting(!) I try oh-so-hard not to scratch, because of course that will exacerbate itching, but have to admit on the very worst episode to gouging my arm quite badly. It JUST.WOULDN'T.STOP!

As to rationally knowing there's nothing there. I do too. IN THEORY. But my brain is battling so hard. I tell myself the rational thing, but then the other side says, "oh yeah, well what about that? That can't be your imagination. It's too real. Just look harder. There's GOT to be something there! There just HAS to be or this wouldn't be happening!!!" And back and forth it goes. Whatever is the cause, my heart goes out to you, because it can suck so sooooo badly!

MM, I'm curious about the nerve damage theory... Because I have a nerve damage problem (totally not mentally related, nor accounting location-wise for the bugs thing), and the pain/numb/zinginess of it is constant, though it does increase pain-wise sometimes. Another area is affected by a pinched nerve, but is problematic according to position. If I change it, there is relief. The type of nerve damage you're referring to -- does that tend to happen in one area and/or on a consistent basis?