Overall prevalence is about 3 to 5%; women are affected more than men, and younger people are affected more than older people. Raynaud syndrome is probably due to an exaggerated alpha-2 adrenergic response that triggers vasospasm; the mechanism is not defined.
Primary Raynaud syndrome is much more common (> 80% of cases) than secondary; it occurs without symptoms or signs of other disorders. In the remaining 20% of patients with Raynaud symptoms, a causative underlying disease (eg, systemic sclerosis) will be evident at initial presentation or diagnosed subsequently.
Secondary Raynaud syndrome accompanies various disorders and conditions, mostly connective tissue disorders (see table Causes of Secondary Raynaud Syndrome).
Causes of Secondary Raynaud Syndrome
Nicotine commonly contributes to secondary Raynaud syndrome but is often overlooked. Raynaud syndrome may accompany migraine headaches, variant angina, and pulmonary hypertension, suggesting that these disorders share a common vasospastic mechanism.
Sensations of coldness, burning pain, paresthesias, or intermittent color changes of one or more digits are precipitated by exposure to cold, emotional stress, or vibration. All can be reversed by removing the stimulus. Rewarming the hands accelerates restoration of normal color and sensation.
Color changes are clearly demarcated across the digit. They may be triphasic (pallor, followed by cyanosis and after warming by erythema due to reactive hyperemia), biphasic (cyanosis, erythema), or uniphasic (pallor or cyanosis only). Changes are often symmetric. Raynaud syndrome does not occur proximal to the metacarpophalangeal joints; it most commonly affects the middle 3 fingers and rarely affects the thumb. Vasospasm may last minutes to hours but is rarely severe enough to cause tissue loss in primary Raynaud syndrome.
Raynaud syndrome secondary to a connective tissue disorder may progress to painful digital gangrene; Raynaud syndrome secondary to systemic sclerosis tends to cause extremely painful, infected ulcers on the fingertips.
Raynaud syndrome itself is diagnosed clinically. Acrocyanosis also causes color change of the digits in response to cold but differs from Raynaud syndrome in that it is persistent, not easily reversed, and does not cause trophic changes, ulcers, or pain.
Primary and secondary forms are distinguished clinically, supported by vascular laboratory studies and blood testing.
A thorough history and physical examination directed at identifying a causative disorder are helpful but rarely diagnostic.
Findings suggesting primary Raynaud syndrome are the following:
Findings suggesting secondary Raynaud syndrome are the following:
Vascular laboratory testing includes measuring digital pulse wave forms and pressures.
The main blood tests are to diagnose collagen vascular diseases (eg, measurement of erythrocyte sedimentation rate [ESR] or C-reactive protein, antinuclear and anti-DNA antibodies, rheumatoid factor, anticentromere antibody, anti-cyclic citrullinated peptide [CCP] antibodies, anti-scleroderma [SCL] 70 antibody) .
Treatment of primary Raynaud syndrome involves avoidance of cold, smoking cessation, and, if stress is a triggering factor, relaxation techniques (eg, biofeedback) or counseling. Drugs are used more often than behavioral treatments because of convenience. Vasodilating calcium channel blockers (eg, extended-release nifedipine 60 to 90 mg orally once a day, amlodipine 5 to 20 mg orally once a day, felodipine 2.5 to 10 mg orally twice a day, or isradipine 2.5 to 5 mg orally twice a day) are most effective, followed by prazosin 1 to 5 mg orally once a day or twice a day. Topical nitroglycerine paste, pentoxifylline 400 mg orally twice or 3 times a day with meals, or both may be effective, but no evidence supports routine use. Beta-blockers, clonidine, and ergot preparations are contraindicated because they cause vasoconstriction and may trigger or worsen symptoms.
Treatment of secondary Raynaud syndrome focuses on the underlying disorder. Calcium channel blockers or prazosin is also indicated, given as above for primary Raynaud syndrome. Antibiotics, analgesics, and, occasionally, surgical debridement may be necessary for ischemic ulcers. Low-dose aspirin may prevent thrombosis but theoretically may worsen vasospasm via prostaglandin inhibition. IV prostaglandins (alprostadil, epoprostenol, iloprost) appear to be effective and may be an option for patients with ischemic digits. However, these drugs are not widely available, and their role is yet to be defined.
Cervical or local sympathectomy is controversial; it is reserved for patients with progressive disability unresponsive to all other measures, including treatment of underlying disorders. Sympathectomy often abolishes the symptoms, but relief may last only 1 to 2 years.
Raynaud syndrome is reversible vasospasm of parts of the hand in response to cold or emotional stress.
Raynaud syndrome may be primary or secondary to another disorder, typically one affecting connective tissue.
Primary Raynaud syndrome, unlike the secondary form, rarely causes gangrene or tissue loss.
Diagnose clinically but consider testing to diagnose a suspected cause.
Avoid cold, smoking, and any other triggers.
Give a vasodilating calcium channel blocker or prazosin.