Patients with fibromyalgia frequently present symptoms of Raynaud’s phenomenon (RP). The underlying cause of Raynaud’s symptoms in fibromyalgia patients and those of primary RP (Raynaud’s that’s not associated with a medical condition that could provoke vasospasm, the sudden constriction of a blood vessel) can be different, although they present similar characteristics, a study says.
These new findings can have major implications not only by improving the classification of Raynaud’s, but also in better management of Raynaud’s symptoms in fibromyalgia patients.
The study, “Symptoms of Raynaud’s phenomenon (RP) in fibromyalgia syndrome are similar to those reported in primary RP despite differences in objective assessment of digital microvascular function and morphology,” was published in the journal Rheumatology International.
Between 2010 and 2012, researchers compared symptoms and specific microvascular alterations in 43 fibromyalgia patients with reported Raynaud’s phenomenon symptoms to those of 85 patients with clinically diagnosed primary RP.
The team performed imaging techniques to determine digital microvascular function through infrared thermography – to determine temperature distribution – and nailfold capillaroscopy when available – to visualize microvascular alterations. The characteristics of patients’ symptoms were determined using a patient-completed questionnaire.
Reported digital color changes, the number of digital color changes, or other RP symptom characteristics showed no differences between the two groups of patients.
In contrast, primary RP patients presented lower skin temperature of the digits, of the back of the hand, and lower thermal gradient (TG) as a measure of average hand temperature compared to fibromyalgia patients with Raynaud’s. This trend persisted with the cold stress test (CST), where patients with primary RP continued to have significantly lower skin temperatures compared to fibromyalgia.
Also, no association between skin temperature and Raynaud’s digital color changes was identified in fibromyalgia patients. In contrast, primary RP patients reported that “blue” digits were associated with lower digital blood flow.
“Our findings suggest that symptoms of RP in [fibromyalgia] may have a different aetiology to those seen in primary RP. These findings have potential implications for both the classification of RP symptoms and the management of RP symptoms in the context of fibromyalgia,” the authors wrote in their report. “Digital color changes reported by patients might reflect the degree of digital microvascular compromise in primary RP.”
The results offer new insights for a better Raynaud’s phenomenom therapy management in the context of fibromyalgia, where effectiveness and safety therapy profiles may differ from those demonstrated for primary Raynaud’s.