Raynaud's syndrome

To fully understand Raynaud's syndrome, it is important to know that our fingers, toes, nose and ears are traversed by very small blood vessels. These vessels allow blood to reach the skin, which helps to nourish and warm it.
When everything is functioning normally, these vessels contract slightly to limit heat loss when it is cold, then dilate to restore circulation. This mechanism helps to maintain a stable body temperature.
But in people with Raynaud's syndrome, this regulation is disrupted. The vessels constrict too tightly or for too long, blocking blood flow. This causes visible symptoms on the skin: colour changes, intense cold sensations, numbness.

Raynaud's syndrome manifests itself in episodes called ‘attacks’ or ‘flare-ups’. These often occur when a person is exposed to the cold, such as when going outside in winter without gloves, touching a cold object, or entering an air-conditioned environment. However, these attacks can also occur during stressful situations or as a result of certain activities or specific medications.
During an attack, the fingers or toes suddenly become very pale, sometimes even white. This phase is due to a lack of blood in the area. They may then turn blue, as the little blood that remains no longer carries enough oxygen. When circulation resumes, the skin turns red and the person often feels tingling, pain or a sudden sensation of heat.
These episodes usually last from a few minutes to an hour. They mainly affect the fingers and toes, but can sometimes affect other parts of the body such as the nose, lips or ears.

The most common form of Raynaud's syndrome, known as ‘primary’ Raynaud's syndrome, has no clearly identified cause. It is often benign, and many people do not require any specific treatment. This form is more common in young women, often between the ages of 20 and 30, and can be hereditary.
The ‘secondary’ form, on the other hand, is linked to other diseases, particularly those affecting the immune system, such as scleroderma, lupus or rheumatoid arthritis. It can also be caused by certain occupations involving exposure to cold or repeated vibrations (such as the use of mechanical tools), smoking, medication, etc. .
In these cases, Raynaud's syndrome is often more severe, more frequent and can lead to complications if left untreated.

The diagnosis of Raynaud's syndrome is based primarily on the symptoms described by the person: the reaction of the fingers or toes to cold or stress, changes in skin colour, intense cold sensation, numbness, or tingling.
During the clinical examination, two simple tests can help guide the diagnosis:

• Allen's test, which checks whether blood is circulating properly in the arteries of the hand.
• The chandelier test, where the patient raises their arms. If this position triggers discomfort, a feeling of heaviness or paleness in the fingers, this may suggest compression of a vessel or nerve in the shoulder.

These tests can distinguish between a benign form of Raynaud's and one linked to an underlying vascular or nerve problem.

To differentiate between the primary and secondary forms, the doctor may use a method called capillaroscopy. This involves examining the tiny vessels at the base of the nail using a small microscope. If any abnormalities are found, this may indicate a secondary form linked to another disease. If the capillaroscopy is abnormal, additional clinical and blood tests to assess the immune and rheumatological status are necessary.

In most cases, especially for the primary form, simple measures are sufficient to limit attacks. The most important thing is to protect yourself from the cold: wear gloves, a hat, thick socks, often several layers, and avoid touching cold objects with your bare hands. It is also advisable to reduce stress, as it can trigger episodes. Smoking should be avoided, as it aggravates the contraction of the blood vessels.
When these measures are not enough, certain treatments may be offered. Doctors generally prescribe medications that help the blood vessels to relax and improve circulation, such as calcium channel blockers. If the person cannot tolerate these treatments or if they are ineffective, other options may be considered: vasodilator medications, locally applied creams, or, as a last resort, procedures to block certain nerves responsible for constricting the blood vessels.
In more severe cases, particularly if circulation is severely reduced and wounds appear, specialised care is required.

In its primary form, Raynaud's syndrome often progresses slowly and without major complications. Episodes may remain stable for years, or even decrease over time. It is rare for this form to cause lasting damage.
However, the secondary form can lead to more serious complications, especially if it is linked to an autoimmune disease. When episodes are frequent and prolonged, the lack of blood can damage the tissue at the tips of the fingers or toes. This can lead to wounds that are difficult to heal, called ulcers, or even tissue death (gangrene) in extreme cases. These situations require prompt medical treatment to avoid serious consequences.

It is recommended to consult a healthcare professional if episodes of discolouration of the fingers or toes occur regularly, even if they are not very painful. Medical advice is particularly important if:

• The episodes become more frequent or last longer than before.
• Other parts of the body begin to be affected (nose, ears, etc.).
• A wound, infection or black area appears on a finger or toe: this may indicate serious tissue damage.

Prompt treatment allows a diagnosis to be made, a potentially more serious secondary form to be ruled out, and appropriate treatment to be put in place.

At the first signs of the condition, the patient may be referred to a specialist, particularly in internal medicine, rheumatology, immunology or angiology, who will assess the form of the syndrome (primary or secondary) using a thorough clinical examination and, if necessary, capillaroscopy and blood tests. Capillaroscopy is performed by our immunology and angiology specialists. 

Is Raynaud's syndrome dangerous?

In its most common form, known as primary Raynaud's syndrome, it is often not serious. It causes temporary discomfort but does not damage tissue. However, in its secondary form, which is linked to another disease, complications such as sores or tissue damage can occur if circulation is interrupted for too long.

How do I know if I have the primary or secondary form?

Only a healthcare professional can make this distinction. They will take into account your age, medical history and the symmetry of your symptoms, and may request tests such as a capillaroscopy or blood test. The primary form usually begins early in life and does not cause skin lesions.

Are all fingers affected?

Not always. Symptoms usually start in one or two fingers. However, it is common for several fingers to be affected over time. The thumbs are often spared. The phenomenon is usually symmetrical, except in certain secondary forms where only one side may be affected.

Can the attacks disappear over time?

Yes, especially in the primary form. Some people see their symptoms diminish or even disappear spontaneously over the years. Others continue to have regular attacks without any worsening. Medical follow-up is still recommended to monitor the progression.

Can Raynaud's syndrome be cured?

There is no ‘cure’ in the strict sense of the word, but many patients learn to control their symptoms through simple everyday measures. In secondary forms, treating the underlying disease often helps to limit attacks. Medication is also available to improve circulation in more severe cases.