 Symptoms may include areas of thickened skin, stiffness, feeling tired, and poor blood flow to the fingers or toes with cold exposure.One form of the condition, known as CREST syndrome, classically results in calcium deposits, Raynaud's syndrome, esophageal problems, thickening of the skin of the fingers and toes, and areas of small dilated blood vessels.The cause is unknown; however, some suspect it may be due to an abnormal immune response.