Raynaud's phenomenon (RAY-noz), in medicine, is a vasospastic disorder causing discoloration of the fingers, toes, and occasionally other extremities, named for French physician Maurice Raynaud (1834 - 1881). The cause of the phenomenon is unknown, but emotional stress and cold are classically triggers, and the discoloration follows a characteristic pattern in time: white, blue and red. It comprises both Raynaud's disease (primary Raynaud's), where the phenomenon is idiopathic, and Raynaud's syndrome (secondary Raynaud's), where it is secondary to something else.
The phenomenon is more common in women than men, with the Framingham Study finding that 5.8% of men and 9.6% of women suffered from it.
There is a familial component to primary Raynaud's, and presentation is typically before 30. Smoking worsens frequency and intensity of attacks, and there is a hormonal component. Sufferers are more likely to have migraine and angina than controls.
It is important to realise that Raynaud's can herald these diseases by periods of more than 20 years in some cases, making it effectively their first presenting symptom. This can be the case in the CREST syndrome, of which Raynaud's is a part.
The condition causes painful, pale, cold extremities. This can often be distressing to those who are not diagnosed, and sometimes it can be obstructive. If someone with Raynaud's is placed in too cold a climate, it could potentially become dangerous.
Unilateral Raynaud's, or that which is present only in the hands or feet, is almost certainly secondary, as primary Raynaud's is a systemic condition. However, a patient's feet may be affected without him or her realizing it.
In pregnancy, this sign normally disappears due to increased surface blood flow.
A careful history will often reveal whether the condition is primary or secondary. Once this has been established, investigations are largely to identify or exclude possible secondary causes.
Digital artery pressure: pressures are measured in the digital arteries before and after cooling the hands. A drop of 15mmHg or more is diagnostic.
Nail fold vasculature: this can be examined under the microscope
Treatment options are dependent on the type of Raynaud's present. Raynaud's syndrome is treated primarily by addressing the underlying cause, but includes all options for Raynaud's disease as well. Treatment of primary Raynaud's focuses on avoiding triggers:
Avoidance of any environmental triggers, e.g. cold, drilling, etc. (although emotional stress is a recognised trigger, it tends to be impossible to consciously avoid).
Warm clothing for the extremities such as mittens or HeatBands
Drug treatment is normally with a calcium channel blocker, frequently nifedipine to prevent arterioconstriction. It has the usual uncommon side effects of headache, flushing, and ankle edema; but normally result in needing to to stop the drug.
Alpha-1 adrenergic blockers such as prazosin can be used to control Raynaud's vasospasms under supervision of a health care provider.
In a study published in the November 8, 2005 issue of Circulation, sildenafil (Viagra) improved both microcirculation and symptoms in patients with secondary Raynaud's phenomenon resistant to vasodilatory therapy. The authors, led by Dr Roland Fries (Gotthard-Schettler-Klinik, Bad Schönborn, Germany), report: "In the present study, capillary blood flow was severely impaired and sometimes hardly detectable in patients with Raynaud's phenomenon. Sildenafil led to a more than 400% increase of flow velocity."
The extract of the Ginkgo biloba leaves (Egb 761, 80mg) may reduce frequency of attacks.
Two separate gels combined on the fingertip (somewhat like two-part epoxy, they cannot be combined before use because they will react) increased blood flow in the fingertips by about three times. One gel contained 5% sodium nitrite and the other contained 5% ascorbic acid. The milliliter of combined gel covered an area of ~3 cm². The gel was wiped off after a few seconds.