The primary condition, which occurs most frequently in a mild form in as many as 20 to 30 percent of young adult women, is usually bilateral, whereas the secondary phenomenon tends to be unilateral. Secondary Raynaud's phenomenon is the first symptom to occur in as many as 70 percent of patients with scleroderma, although the systemic disease may not appear for as long as 20 years. Primary and secondary Raynaud's phenomenon can often be managed conservatively by protecting the hands and feet from exposure to cold. Behavioral techniques, including biofeedback and other relaxation methods, may be helpful. Direct-acting vasodilator drugs are ineffective.
New therapies continue to be proposed and evaluated, and most show some efficacy in most patients.
Iloprost, a prostaglandin analogue, has been shown to be effective when given intravenously, but an oral preparation provided only limited benefit in a recent study. Administration of calcitonin gene-related peptide, one of the neuropeptide vasoactive mediators, also has shown some benefit. Although overactivity of the sympathetic nervous system in the locally involved area previously was thought to cause reflex sympathetic dystrophy, disordered regulation of the vasoactive mediators most probably is the cause.