Raynaud phenomenon (RP)
Raynaud phenomenon (RP) is a syndrome of paroxysmal digital ischemia, most commonly caused by an exaggerated response of digital arterioles to cold or emotional stress. The initial phase of RP, mediated by excessive vasoconstriction, consists of well-demarcated digital pallor or cyanosis; the subsequent (recovery) phase of RP, caused by vasodilation, leads to intense hyperemia and rubor. Although RP chiefly affects fingers, it can also affect toes and other acral areas such as the nose and ears.
RP is classified as primary (idiopathic or Raynaud disease) or secondary. Nearly one-third of the population reports being “sensitive to the cold” but does not experience the paroxysms of digital pallor, cyanosis, and erythema characteristic of RP. Primary RP occurs in 2–6% of adults, is especially common in young women, and poses more of a nuisance than a threat to good health.
In contrast, secondary RP is less common, is chiefly associated with rheumatic diseases (especially scleroderma), and is frequently severe enough to cause digital ulceration or gangrene.
“Raynaud’s (ray-NOSE) disease causes some areas of your body — such as your fingers and toes — to feel numb and cold in response to cold temperatures or stress. In Raynaud’s disease, smaller arteries that supply blood to your skin become narrow, limiting blood flow to affected areas (vasospasm)”
The differentiation from Buerger disease (thromboangiitis obliterans) is usually not difficult, since thromboangiitis obliterans is generally a disease of men, particularly smokers; peripheral pulses are often diminished or absent; and, when RP occurs in association with thromboangiitis obliterans, it is usually in only one or two digits.
In acrocyanosis, cyanosis of the hands is permanent and diffuse; the sharp and paroxysmal line of demarcation with pallor does not occur with acrocyanosis. Frostbite may lead to chronic RP.
RP may be mimicked by type I cryoglobulinemia, in which a monoclonal antibody cryoprecipitates in the cooler distal circulation. Type I cryoglobulinemia is usually associated with plasma cell myeloma or with lymphoproliferative disorders.
Erythromelalgia can mimic the rubor phase of RP; exacerbation by heat and relief with cold readily distinguish erythromelalgia from RP.
Patients should wear gloves or mittens whenever outside in temperatures that precipitate attacks. Keeping the body warm is also a cornerstone of initial therapy. Wearing warm shirts, coats, and hats will help prevent the exaggerated vasospasm that causes RP and that is not prevented by warming only the hands.
The hands should be protected from injury at all times; wounds heal slowly, and infections are consequently hard to control.
Softening and lubricating lotion to control the fissured dry skin should be applied to the hands frequently. Smoking should be stopped and sympathomimetic drugs (eg, decongestants, diet pills, and amphetamines) should be avoided.
For most patients with primary RP, general measures alone are sufficient to control symptoms. Medical or surgical therapy should be considered in patients who have severe symptoms or are experiencing tissue injury from digital ischemia.
Calcium channel blockers are first-line therapy for RP. Calcium channel blockers produce a modest benefit and are more effective in primary RP than secondary RP. Slow release nifedipine (30–180 mg/day orally), amlodipine (5–20 mg/day orally), felodipine, isradipine, or nisoldipine are popular and more effective than verapamil, nicardipine, and diltiazem.
Other medications that are sometimes effective in treating RP include angiotensin-converting enzyme inhibitors, sympatholytic agents (eg, prazosin), topical nitrates, phosphodiesterase inhibitors (eg, sildenafil, tadalafil, and vardenafil), selective serotonin reuptake inhibitors (fluoxetine), endothelin-receptor inhibitors (ie, bosentan), statins, parenteral prostaglandins (prostaglandin E1), and oral prostaglandins (misoprostol).
Sympathectomy may be indicated when attacks have become frequent and severe, when they interfere with work and well-being, and particularly when trophic changes have developed and medical measures have failed. Cervical sympathectomy is modestly effective for primary but not secondary RP. Digital sympathectomy may improve secondary RP.