I know these posts are over a year old but answering none-the-less. I have suffered with this exact same thing for several years. It has driven me to the point of insanity at times. One last google search and I discovered what it is. And it's a REAL thing, not something of my imagination. It's called paresthetica notalgia. I was started on a low dose of amitriptyline (25 mg) at night and as long as I take it, I have no symptoms from this. Gabapentin is also another option.
Hi there, I've just been reading this blog and when I came across you post it seemed that you symptoms and suspected cause it identical to my situation. I've been really trying to focus on my bad posture lately and it seems to bring on the strange tingling on the left side of my back, just below my shoulder blade. I just wanted to check in with you to see how things are going for you now?