What is Raynaud phenomenon?
Raynaud phenomenon is an episodic reduction in the blood supply to the fingers and/or toes occurring mainly in response to cold (vasospastic disease). It can be divided into two main types:
- Primary Raynaud phenomenon, also known as Raynaud Disease. This is not associated with any other conditions. It affects at least one in five young women (and is less common in males, children and older individuals). It as an exaggeration of the normal response of the circulation to cold.
- Secondary Raynaud phenomenon has the same symptoms due to an identifiable cause or condition.
How do I know if I have Raynaud phenomenon?
An attack of Raynaud phenomenon is triggered by exposure to cold, such as going out into a cold wind or immersing the hands in cold water. Sudden emotional or psychological upsets can also bring on an attack. The hands are most often affected, but it sometimes involves the feet and occasionally the tip of the nose or the earlobes.
Typically, one or more fingers will turn white and numb and, on rewarming, blue due to a sluggish blood flow. This is sometimes followed by a bright red colour and swelling due to a compensatory increase in blood flow before the normal skin colour and sensation are restored.
Attacks may be painful and can last from minutes to hours.
How do I distinguish primary from secondary Raynaud phenomenon?
Primary Raynaud phenomenon is about twice as common as the secondary form. It usually starts under 25 years of age and is five times more common in women than in men. Individuals often recall cold intolerance dating back to childhood.
Patients with secondary Raynaud phenomenon often have the symptoms of an associated condition (see below) or are on medication that can cause Raynaud phenomenon as a side effect. If you develop Raynaud phenomenon for the first time when older than 25 years and do not recall any cold intolerance in childhood, seek medical advice.
What are the causes of secondary Raynaud phenomenon?
Secondary Raynaud phenomenon is much less common than the primary form. It can be associated with a variety of underlying conditions.
Connective tissue diseases
Connective tissue diseases are believed to be due to disordered regulation of the immune system. The underlying connective tissue disease may not be apparent when Raynaud phenomenon first occurs.
The one most likely to cause Raynaud phenomenon is systemic sclerosis (a systemic form of scleroderma), which has diffuse cutaneous and localised cutaneous forms. The hallmark of this condition is thickening and tightening of the skin, especially on the hands and face. Dilated blood vessels (telangiectases) and deposits of chalky material under the skin (calcinosis) are also features. Ulceration of the fingertips may occur if vasospasm is severe.
Raynaud phenomenon also occurs in systemic lupus erythematosus, dermatomyositis, Sjogren syndrome, and granulomatosis with polyangiitis.
Medications aggravating or causing Raynaud phenomenon include beta-blockers (widely used for angina, high blood pressure, and anxiety), migraine remedies containing ergotamine or methysergide, bleomycin and other chemotherapy agents (for cancer treatment), clonidine (for high blood pressure, migraine or flushing), bromocriptine (for Parkinsonism and some other conditions), imipramine (for depression) and rarely, the oral contraceptive pill. If medication is the cause, stopping it can result in rapid improvement.
Raynaud phenomenon may sometimes indicate underlying atherosclerosis and Buerger disease, especially in smokers.
Raynaud phenomenon may develop in a limb affected by a stroke and can also occur in multiple sclerosis and polio. Rarely, Raynaud phenomenon is due to an extra rib causing compression on the nerves and blood vessels.
Occupations associated with Raynaud phenomenon include construction workers using a vibrating tool (eg, pneumatic drill) and industrial workers exposed to vinyl chloride polymerisation processes.
Disorders that increase the viscosity (thickness) of the blood can also cause Raynaud phenomenon, by reducing blood flow through the small blood vessels in the fingers and toes.
Raynaud phenomenon has been associated with hypothyroidism.
Information Source: DermNet NZ: https://dermnetnz.org/topics/raynaud-phenomenon/