Diagnosis of Raynaud's Disease
To diagnose Raynaud's disease, the physician evaluates the symptoms and their patterns and performs a number of diagnostic tests. Following the evaluation, the next step in diagnosis is a cold simulation test. This test recreates a Raynaud's attack for the doctor to observe first-hand.
In this test, temperature sensors are attached to the affected area and a reading is taken. The area is then exposed to cold water or air, triggering a Raynaud's attack. The physician takes another reading and notes the length of time it takes for the affected area to return to the original temperature. This interval is longer than normal for patients with Raynaud's disease.
A diagnosis of Raynaud's also involves checking for conditions that can cause secondary Raynaud's. In a test called a nailfold capillaroscopy, the physician applies a drop of oil to the skin at the base of the finger nail and then examines the area under a microscope. If the blood vessels show are enlarged or inflamed, an underlying illness may be causing symptoms and further testing is needed.
An antinuclear antibody (ANA) test can indicate whether the immune system is producing antibodies to fight disease. Positive test results are common in people who have connective tissue and autoimmune diseases, which are frequently associated with secondary Raynaud's.
The erythrocyte sedimentation rate (ESR) test also can be used to help diagnose conditions associated with secondary Raynaud's. In this test, a sample of blood is examined and the rate at which blood cells fall to the bottom of the tube is determined. If this occurs at a faster-than-normal rate, an autoimmune or inflammatory disease may be indicated.
If the results of all the tests are normal and no cause is apparent, then primary Raynaud's is diagnosed.