Yup had this too and still do on occasion, for me I think it's anxiety related, it usually hits me first thing it the morning when I wake early with anxiety. Gawd I
HATE this waking early with anxiety most probably from high cortisol levels which are probably high from the ongoing anxiety, sheeesh what a viscious cycle

. Sometimes I get it down the fronts of my legs too and it comes in surges so I'm fairly convinced it's adrenal surges from anxiety. Last year when I was on an AD and had virtually no anxiety I never had this sensation for months and months on end. Now I'm virtually weaned off the AD and the anxiety is back and so are all the other wonderful things that go along with it

. I have a major health anxiety worry at present which is slowly doing my head in but I'm hoping the new holistic doctor I will be seeing again in 2 weeks after some follow up blood tests might put my mind at ease as I can't live my life like this for much longer, it is no quality of life to be anxious all the time.
Rox