Acrocyanosis

This painless disorder is caused by constriction or narrowing of small blood vessels in the skin. This results in less blood being delivered to the hands and feet, causing them to turn blue and become cold and sweaty. Localized swelling may also occur.

Cold temperatures can worsen the symptoms, while warmth can relieve them. The disease is seen mainly in women and the effect of the disorder is mainly cosmetic. 

Treatment focuses on keeping the foot warm and the blood circulating normally. It may include wearing insulated boots, thin polypropylene liner socks to wick the moisture away from the skin, and/or use of an insulated sock to maintain normal skin temperature. The disorder itself cannot be remedied, but does not worsen over time.