The symptoms of CREST syndrome include red spots or lines on the skin, hardening of the skin, difficulty swallowing, bumps under the skin and a condition known as Raynaud's phenomenon, according to Mayo Clinic. While some people develop symptoms rapidly, most people develop symptoms gradually over time.
CREST syndrome is a subtype of a skin condition called sclerodema, which can not only harden the skin on a person's arms, legs and face, but can also affect a person's digestive tract, states WebMD. The condition may also cause tiny calcium deposits to form under the skin, resulting in bumpy skin, notes Mayo Clinic. Additionally, sclerodema may cause a person's blood vessels to swell, resulting in the appearance of red lines or spots under the skin.
Raynaud's phenomenon is another side effect of CREST syndrome and is often one of the first signs of the disorder, reports Mayo Clinic. This condition happens when small blood vessels in a person's hands or toes go into spasms in response to emotional stress or cold. This can block the supply of blood in those areas, causing white skin that eventually turns blue and becomes numb and cold. However, many people who develop Raynaud's phenomenon never go on to develop sclerodema, explains WebMD.