If it's just a skin condition, neem soap may help.
Your definition of the crawling feeling isn't quite like what I suffered with for several months until they did a lot of tests (blood tests) and it showed my kidney was shutting down. I itched everywhere. Couldn't sleep. Thought I had bed bugs, left my lights on so they would go away, because they are nocturnal, but nothing worked. I only saw my kidney doctor every 6 months so I can pretty much say I suffered for most of those months before he ran the tests and stuck me into the hospital to flush out my one and only kidney. IV's in both arms. It was that or dialysis and I am not ready for that yet. The kidneys actually filter your blood, so you could have an infection somewhere. Check with your doctor. There is always a reason for what is happening. He can order tests and check you out. Good luck.