Hello..
I recalled this page (link below) after reading Debby's post to Vicc describing her hot RSD symptoms yeat cold extremitys

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VASCULAR ABNORMALITIES IN ERYTHROMELALGIA

Blood perfusion through skin capillaries primarily serves nutritional needs, whereas arteriovenous anastomoses facilitate heat and temperature regulation. Recent research suggests that in erythromelalgia, some precapillary sphincters may be constricted while the arteriovenous shunts are open, creating an imbalance of increased total perfusion yet deficient nutritive perfusion.1-4,17

The result is "the coexistence of hypoxia and hyperemia in affected skin."3 (p 191) The products of tissue hypoxia trigger increased local blood flow, worsening the redness, warmth, and pain. This may explain why higher ambient temperatures exacerbate symptoms of erythromelalgia.

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I note that Sjogren's syndrome (which is also RSD) is listed as one of the 'Disorders associated with erythromelaigia' under 'Mixed connective tissue disorders'.

http://www.angelfire.com/journal2/sa...NICAL%20REVIEW

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Erythromelalgia is a rare condition that has remained an enigma diagnostically and therapeutically for decades. It has been assumed that erythromelalgia, which is characterized by hot, red, intensely painful feet or hands, may be the opposite of Raynaud's phenomenon. However, new research suggests that these two disorders are more similar than dissimilar. Erythromelalgia usually follows a chronic, sometimes progressive and disabling course. New evidence suggests that this may not be a disease entity at all, but a syndrome of dysfunctional vascular dynamics; recent studies demonstrate that this dysfunction is reversible in some patients. This review article presents the latest theories and successful treatments for erythromelalgia, and data from a survey of members of The Erythromelalgia Association, which was formed to provide information about erythromelalgia to doctors and patients. (J Am Acad Dermatol 2000;43:841-7.)

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