I have not heard of this being a fibro symptom. BUT fibro is so varied that it could be.
I think that first, though, you should try treating it in various ways to find out if it is something else, and not fibro, because it may be something you can cure.
First, stop using whatever soap or body wash you use, and stop using your shampoo/conditioner, or anything else you put onto your skin or hair.
Do not use any of it for a couple of week and see if that changes anything. (Yes, you can go 2 weeks without washing your hair with shampoo. Just rinse it thoroughly in warm (not hot) water. And you don't need soap to get clean for that period of time, either.
If you simply cannot go without soap or shampoo then go to a natural health store and buy both a shower wash and a shampoo that don't have soap in them at all, and are plant-based, without any chemicals of any kind, and use that.
Second, try an all-natural no chemicals lotion on your skin. Again, get something with as few ingredients as possible and do not put anything on your skin that has any chemicals in it.
If these things do not change it, stop using any chemical cleaning products whatever for 2 weeks.
Also try changing your diet. Go gluten-free completely for 2 weeks. Lactose free the same. Etc.
But only do one of these things at a time or else you will not know which one is helping you.
there are so many toxins in most of the things that most people eat, use on their hair, and put on their bodies, not to mention cleaning products, perfumes and so on, that this could very well be an intolerance that has developed in you. Only removing these methodically from your use and watching the results will tell you if it is one of those things or not.