This sounds like a serious group of symptoms, but it's not one that as a dermatologist I can offer insight into. In fact, I don't really know what you mean by "very prickly skin, worse at night," especially when you add, "Do not have a rash." It sounds as though you need a full workup, which may include radiologic evaluation of the knee nodule and possible biopsy. If there's anything to see on the skin, a dermatologist may be of help too. Your PCP is the one who should direct this evaluation. Sorry I have no more to add.
Best.
Dr. Rockoff
turn into cancer?