Hi Laurie,
Skin problems, including hives, are so common with fibro. Here's some info from a previous response of mine, which includes some of my quotes for an article (so it must be pretty credible, right?!).
"Around 50% of people with FM suffer with skin problems according to Dr Mark Pellegrino from Canton, Ohio, who has treated over 20,000 fibromyalgia patients. "Patients report tingling, numbness, crawling sensations and a burning or sunburn type feeling," he reports. "The main skin symptoms you will see on examination are areas of dry, flaky skin, non-specific red rashes, blotchy or mottled skin and bruising."
"Studies show overactive skin pain receptors," explains Pellegrino. "So the skin can indeed be painful and hurt at the lightest touch. The hypersensitivity of the autonomic nerves result in the symptoms of itching, numbness, tingling, burning and crawling sensations, as well as neurovascular changes leading to cold, dry, sweaty or mottled skin. There is also a phenomenon known as dermatographism where scratching your finger along the skin will cause a red mark or rash to form," he adds. "This is most pronounced in the skin overlying painful muscles and thought to be due to dysfunctional autonomic nerves overreacting to the pressure and causing a low-grade skin irritation."
I think the fibro's hypersensitized small skin nerves/autonomics predispose us to these skin problems. Our skin may become too dry because of the dysfunctional sweat gland nerves, and then our skin may try to correct this "dry irritation" by bringing "moisture" to the area. But the moisture may arrive as bumps or bubbles on the skin (known as vesicles) for some of us. These vesicles are yet another dysfunctional display of our skin autonomics. Yes it would be much easier and cosmetically better if our skin could just add more moisture like normal people, but our fibro does not make things easy for us.
So we try to correct dryness in a dysfunctional way, and end up creating "moisture irritation" signals, I believe. Then the dryness cycle starts over and so on and on and on..... I'm sure various allergies, stressors, irritants, co-exisitng conditions, nutitional factors etc all play a role in these skin issues. In some, "hives" may be the dominant skin lesion. Your doctor can review your skin issues to make sure other causes are considered.
The FMoral of this story: Our fibro problems are skin-deep.
Take care,
Dr. P