- Raynaud’s phenomenon causes your extremities to whiten and feel ice cold. It’s caused by sudden constrictions of your blood vessels.
- The cold simulation test is used to help diagnose Raynaud’s by measuring how quickly your skin returns to a normal temperature from being cold.
- This test is a preliminary step and other tests must be conducted for a full diagnosis of Raynaud’s.
Raynaud’s phenomenon is a whitening of your fingers, toes, ears, or nose. It’s caused by vasospasms, or sudden constrictions of your blood vessels. These constrictions block or slow blood flow to your extremities, causing them to whiten and feel ice cold.
Your skin may first turn white and then blue, and you may feel numbness or pain. When normal blood flow returns, your skin will turn red and may throb and tingle. It will eventually go back to a normal color.
Stress and cold temperatures can trigger an attack of Raynaud’s. People with Raynaud’s have spasms in their blood vessels when exposed to cold temperatures or strong emotions. The duration of episodes ranges from minutes to hours.
According to the National Heart, Lung, and Blood Institute, about five percent of the U.S. population has Raynaud’s.
There are two types of Raynaud’s: primary and secondary. Primary Raynaud’s is more common and secondary Raynaud’s tends to be more severe.
The cause of primary Raynaud’s isn’t known. According to the Mayo Clinic, this type of Raynaud’s is:
- more common in women than men
- usually seen in people between the ages of 15 and 30
- seen in people who live in colder climates
- more prevalent if you have a parent or sibling with it
Secondary Raynaud’s is caused by another disease, condition, or other factor. Some causes of secondary Raynaud’s include:
- artery diseases, such as Buerger’s disease or atherosclerosis
- medications that narrow the arteries, such as some beta-blockers and certain cancer drugs
- autoimmune conditions, such as rheumatoid arthritis, lupus, and scleroderma
- repeated injury to the arteries, especially from activities that cause vibration, such as jackhammering
- thoracic outlet syndrome
Secondary Raynaud’s is harder to manage than primary, as you will have to treat the disease or disorder causing it.
The cold simulation test is designed to trigger symptoms of Raynaud’s and is used in conjunction with other tests to diagnose the condition.
The test involves a few simple steps:
- A small temperature-measuring device is attached to your fingers with tape.
- Your hands are placed in ice water to trigger symptoms, and then removed.
- The measuring device records how long it takes your fingers to return to normal body temperature.
The test may cause some mild discomfort but there are no risks associated with it. No specific preparations are needed for the test.
If your finger temperature returns to normal within 15 minutes, your test results are normal. If it takes longer than 20 minutes, you have abnormal results and you may have Raynaud’s.
Your doctor will order more tests if you have abnormal results. These other tests include:
- nailfold capillaroscopy, a test to look at the capillaries under your fingernails
- antinuclear antibodies test (ANA), to test for autoimmune disorders and diseases in your connective tissues
- erythrocyte sedimentation rate (ESR), used to test for inflammatory or autoimmune disorders
- C-reactive protein test
The main concern for people with Raynaud’s is damage to your skin tissue. If tissue damage is severe, fingers and toes may need to be removed. Treatment aims to minimize the number and severity of attacks.
You can prevent a Raynaud’s attack by:
- keeping warm, in particular your hands and feet
- controlling stress, as it can trigger an attack
- exercising regularly to promote good circulation and good overall health
- not smoking
- avoiding medications that constrict your arteries or reduce blood flow
There are several tests to diagnose Raynaud’s phenomenon. Your doctor will typically use the cold simulation test as a preliminary test. If the results are abnormal, they’ll proceed with other tests for a complete diagnosis.
Although there’s no cure for Raynaud’s, treatment aims to control and prevent attacks to keep your skin tissue healthy.