Raynaud's Phenomenon

Raynaud's phenomenon (RAY-noz), in medicine, is a vasospastic disorder causing discoloration of the fingers, toes, and occasionally other extremities. 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.

Incidence
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.

Epidemiology
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.

Secondary Raynaud's has a number of associations:
 * Connective tissue disorders:
 * scleroderma
 * Systemic lupus erythematosus
 * rheumatoid arthritis
 * Sjögren's syndrome
 * dermatomyositis
 * polymyositis
 * Obstructive disorders
 * atherosclerosis
 * Buerger's disease
 * subclavian aneurysms
 * thoracic outlet syndrome
 * Drugs
 * Beta-blockers
 * cytotoxic drugs - particularly chemotherapeutics and most especially bleomycin
 * cyclosporin
 * gotamine
 * sulfasalazine
 * Occupation
 * jobs involving vibration, particularly drilling
 * exposure to the dye vinyl chloride
 * exposure to the cold (e.g. by working packing frozen food)
 * Others
 * hypothyroidism
 * cryoglobulinemia
 * malignancy
 * reflex sympathetic dystrophy

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.

Symptoms
The condition causes painful, pale, cold extremities. This is often distressing, impinges on quality of life, and is potentially 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 their realising.

In pregnancy, this sign normally disappears due to increased surface blood flow.

!!Investigations 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.
 * Doppler ultrasound: to assess flow
 * Full blood count: this can reveal a normocytic anaemia suggesting the anemia of chronic disease or renal failure
 * Urea & Electrolytes: this can reveal renal impairment
 * Thyroid function tests: this can reveal hypothyroidism
 * An autoantibody screen, tests for rheumatoid factor, ESR and CRP, which may reveal specific causative illnesses or a generalised inflammatory process
 * Nail fold vasculature: this can be examined under the microscope

Treatment
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 focusses 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 consciously to avoid).
 * Warm clothing for the extremities, e.g. mittens.
 * Hormone regulation and assessment of the type of oral contraceptive pill taken, if any. Contraception which is low in oestrogen is preferable, and the progesterone only pill is often prescribed.
 * Smoking cessation.
 * Drug treatment is normally with a calcium channel blocker, frequently nifedipine to prevent arterioconstriction. It has the usual side effects of headache, flushing, and ankle oedema, and patients often stop treatment, preferring the symptoms of Raynaud's to the symptoms of the drug.
 * There is some evidence for Angiotensin II receptor antagonists (often Losartan) in reduction of frequency and severity of attacks.
 * In intractable cases, sympathectomy and infusions of prostaglandins may be tried, with amputation in exceptionally severe cases.