Raynaud's phenomenon (RP) is a common vasospastic disorder characterized by transient digital ischemia triggered by cold exposure or emotional stress. It is classified as primary or secondary, the latter often associated with autoimmune connective tissue diseases such as systemic sclerosis, mixed connective tissue disease, and Sjögren's disease /autoimmune epithelitis (SjD/AE). Although primary RP is typically benign, some patients progress to secondary forms, highlighting the need for careful follow-up. RP pathogenesis reflects interactions between vascular, neural, and immune mechanisms. Increased sensitivity of α₂-adrenergic receptors, heightened sympathetic activity, and endothelial dysfunction drive exaggerated vasoconstriction. Emerging evidence also supports an immune-mediated component, with functional autoantibodies targeting G protein-coupled receptors that may alter vascular tone. Genetic studies implicate adrenergic and immune pathways in susceptibility. Nailfold capillaroscopy aids early diagnosis and risk stratification. Management includes lifestyle measures and vasodilators such as calcium channel blockers and phosphodiesterase-5 inhibitors, while botulinum toxin A shows promise.
Moutsopoulos et al. (Sun,) studied this question.