**6.8. Raynaud's phenomenon in fibromyalgia**

Fibromyalgia is an idiopathic, chronic, musculoskeletal, pain syndrome characterized with diffuse pain and presence of multiple tender points [67]. Primary fibromyalgia is an isolated disorder, while secondary fibromyalgia could be observed in different rheumatic diseases, e.g., RA, SLE, Sjögren syndrome, etc. [68]. RP is met in both primary and secondary fibromyalgia. The frequency of RP in fibromyalgia patients is about 17–30% [69, 70]. In an own study that included 26 patients with primary fibromyalgia, the most frequent capillaroscopic finding was the presence of dilated capillary loops analogous to primary RP. Capillaroscopic signs of microangiopathy were not detected [71].
