I have this same problem. Have had it for about a year now. I've been to the dermatologist 3 times. At first we tried to rule out allergies. It could be that you're using a new detergent, soap, or your water in the shower is too hot. It drives me crazy. The only thing I've found that works is, believe it or not, an anti-anxiety drug. I tried a bunch of different allergy medications with no success, but this drug is supposed to have the side effect of helping with this itching. I don't know what else to tell you. You might try seeing a dermatologist or an allergy specialist. Good luck!
I agree, thyroid. And so often it's a major factor in Fibro. You may have to push your doc to go beyond the basic traditional TSH screen. The itching, if thyroid related, is usually caused by one of 3 different thyroid antibodies. So, a complete thyroid panel, including free T3, free T4, and all thyroid antibodies is what you need to ask for.
And then make sure your doc interprets according to current Am. Assoc. of Clinical Endocrinlogy (2002) standards. The vast majority of docs & labs in the USA are using outdated standards, so many people are missing out on treatment.
I have had horrible itchy skin for years. I have been tested over and over again for thyroid and everything else under the sun. The only thing I could ever take is antihistimines. No one ever seems to know the answer.