The purpose of this study is to examine the characteristics of the nerves and the small veins in the skin of people with fibromyalgia. This information will then be used to identify possible processes in the skin that may help explain why some people feel pain relief with the study drug (milnacipran) and others do not. The investigators expect to learn more about the pathophysiology of fibromyalgia and the way in which milnacipran acts on these patients. The investigators hypotheses are: