This is a reply to Salus, don't know if it will end up in the right place, this is really weird I didn't think I would find anything about this anywhere but straight away I got your post and yes that is exactly what happens all the time, I look to see if I'm being stung or pricked by something or someone, it's gets pretty painful sometimes !!!!!!
I suspect it could be a acupuncture effect kind of thing, I know that when I press the calf of my leg I get a sharp pain in my right abdomen, same sort of feeling .
I thought it could be something to do with the digestion, I really wonder about it but feel better to know that this happens to others.
I know I have gall bladder problems but am managing those quite well by eating carefully, very little and very little fat, so maybe it could be that !!!???
Also I used antidepressants for a while and a muscle relaxant, Xanax, all very briefly because I'm scared of that stuff, and I know that can give you withdrawal feelings like crawly skin, so who knows.
Not really worried about it though, but wondering what it might be.