This test looks for reduced blood flow in the fingers after they are exposed to cold temperatures. It measures the temperature of each finger after cold exposure.
A cold stimulation test may be advised when a healthcare professional suspects Raynaud's phenomenon. This condition causes the small arteries of the fingers, toes, ears, or nose to go into spasm. The spasm causes changes in skin color. Feelings of numbness and pain also often occur.
Cold temperatures or emotional stress can bring on symptoms of Raynaud's phenomenon. When this condition lasts for 2 years or more and an underlying cause cannot be found, it is called Raynaud's disease. The cold stimulation test is used to see if a person's symptoms are from Raynaud's phenomenon or from other causes of low blood flow, such as atherosclerosis.
A heat sensor is attached to the person's fingers to measure their normal temperature. Then, each finger is chilled with cold water or some other device. The fingers are removed from the cold after a short period of time. The skin temperature of the fingers is measured every 5 minutes until it returns to normal.
No special preparation is needed for this test.
Normally, cold causes little decrease in blood flow to the fingers. Skin temperature generally returns to normal within 15 minutes. Raynaud's phenomenon may be present if it takes more than 20 minutes for the fingers to return to normal temperature.
Anderson, Kenneth N. and Lois E. Anderson, Mosby's Pocket Dictionary of Medicine, Nursing,&Allied Health, Second Edition, Mosby, 1994.
Farrington, Nancy K. and Paul g. Sutej, "Cold Extemities: Investigation and Management of Raynaud's Phenomenon," Journal of Southern Orthopaedic Association, Spring, 1996.