Cold Stimulation Test

What is a cold stimulation test?

A cold stimulation test involves placing your fingers in an ice water bath to find out if you have Raynaud's syndrome. Raynaud's syndrome, also known as Raynaud's disease or Raynaud's phenomenon, is a condition that causes brief episodes where little or no blood flows to certain parts of your body after exposure to cold or sometimes stress. It mostly affects fingers and/or toes.

A Raynaud's episode can be triggered by very mild and limited exposure to cold, such as taking food out of the freezer or holding a cold drink. When an episode happens, your skin may feel cold and numb. It may also make your skin turn white or blue. As blood flow returns, your skin may tingle, throb, or turn red. It usually takes about 15 minutes for normal blood flow to return.

There are two forms of Raynaud's syndrome:

• Primary Raynaud's, a fairly common and mild condition. It is not associated with any other health problem. Symptoms usually start between the ages of 15 and 25. Most people with primary Raynaud's syndrome can manage their symptoms without medical treatment.
• Secondary Raynaud's, often referred to as Raynaud's phenomenon, is less common than primary Raynaud's but more serious. Symptoms may include skin ulcers (open sores caused by poor blood flow) or skin infections. Symptoms usually start between the ages of 35 and 40. Secondary Raynaud's is most often caused by another medical condition. These include immune system disorders and connective tissue diseases. Connective tissue diseases affect blood flow to tissues and organs.

Other names: cold challenge test

What is it used for?

A cold stimulation test is used to diagnose Raynaud's syndrome.

Why do I need a cold stimulation test?

You may need this test if you have symptoms of Raynaud's syndrome. Symptoms usually show up after exposure to cold. They mostly affect fingers and toes and include:

• Skin that turns white or blue
• Skin that is numb and painful
• Skin that takes a long time to warm up after exposure

What happens during a cold stimulation test?

• A small device that measures temperature will be taped to your fingers.
• Your provider will record the temperature.
• You will then place your hands into an ice water bath for 20 seconds.
• You will remove your hands from the ice water.
• Your provider will record your finger temperature every five minutes for up to 20 minutes, or until your temperature returns to the same as it was before the ice water bath.

Will I need to do anything to prepare for the test?

You don't need any special preparations for a cold stimulation test.

Are there any risks to the test?

You may feel some discomfort while your hands are in the ice water.

What do the results mean?

If it takes 20 minutes or more for your finger temperature to return to normal after the ice water bath, it probably means you have Raynaud's syndrome. If your symptoms are severe and/or you are age 35 or older, you may have secondary Raynaud's syndrome. Secondary Raynaud's can be caused by several disorders, including:

• Scleroderma, a disease that causes hardening of the skin and other body tissues
• Sjögren's syndrome, a disorder that causes dryness of the eyes and mouth
• Lupus, an autoimmune disorder that affects multiple parts of the body, including the joints, blood vessels, kidneys, and brain
• Rheumatoid arthritis, an autoimmune disorder that causes pain, swelling, and stiffness of the joints
• A blood disorder, such as polycythemia vera, a disease that causes your body to make too many red blood cells
• Pulmonary hypertension, a type of high blood pressure that affects arteries in your lungs and heart

If your provider thinks you have secondary Raynaud's syndrome, he or she may order more tests to help diagnose the disorder that is causing it. These tests include:

• Nailfold capillaroscopy. For this test, your provider will place a drop of oil on the base of one of your fingernails. The nail area is then examined under a microscope. If abnormal arteries are seen, it can be a sign of scleroderma or other connective tissue disease.
• Blood tests to check for immune system disorders. These include an antinuclear antibody (ANA) test, erythrocyte sedimentation rate (ESR), and C-reactive protein.

If you have questions about your results, talk to your health care provider.

Is there anything else I need to know about a cold stimulation test?

There are steps you can take that may help you avoid or reduce the symptoms of Raynaud's syndrome, including:

• Dressing extra warmly for cold weather. This includes wearing a hat, mittens, scarf, and heavy socks.
• Using battery- or chemical-operated hand and/or foot warmers
• Turning down air conditioning and wearing a sweater or jacket when in an air-conditioned space
• Getting regular exercise, which increases blood flow
• Limiting caffeine and alcohol
• Avoiding stress

These changes should be enough to manage the symptoms of primary Raynaud's syndrome. If your symptoms are causing too much discomfort, or if you have secondary Raynaud's syndrome, your provider may also prescribe medicines that can help open your blood vessels.