Quantifying digital vascular disease in patients with primary Raynaud's phenomenon and systemic sclerosis.

In primary and secondary Raynaud’s phenomenon, measurement of activity or severity, or both, of the digital vascular disease is a major challenge. We need to identify objective measures of digital vascular disease that are helpful in predicting those patients with Raynaud’s who have underlying connective tissue disease, and to measure reliably digital vascular disease progression, and responses to treatment. None of the various physiological measurement techniques used in the assessment of patients with primary or secondary Raynaud’s are ideal. In this review we outline these techniques, highlighting their applications and limitations. The discussion concentrates on the physiological assessment of patients with primary Raynaud’s phenomenon (PRP) and systemic sclerosis (SSc), but is also applicable to other connective tissue diseases.We have not included biochemical markers of vascular injury or measurement of tissue oxygen levels.