I also have FM and was have had itchy skin for no known reason for many, many years. I recently had the ElisaACT test done which tests for delayed reactions to foods, medications and chemicals. It showed I was allergic to the SLS in soap. This is sodium lauryl sulfate which if you google, you will see is a major skin irritant! It's in shampoo, toothpaste and soap. I went to Whole Foods (amazon also carries sls free products) and since switching, my skin problems have disappeared! I'd wake up in the middle of the night with my skin itching SO badly for no apparent reason. If you have sensitivities, I highly recommend the ElisaACT test, it has made a huge difference in my FM pain.