This photo is of a Raynaud's attack in a systemic scleroderma patient. Note the dark, dusky blue tinge in most fingers.

Raynaud's causes spasms of the blood vessels, which can shut down circulation to the affected areas, usually for a few minutes at a time. The temporary lack of blood flow to the area causes distinct color changes, often a stark, waxy white; sometimes a dusky blue; and as the circulation returns, the areas sometimes turn a bright pink or red. (Also see: What is Raynaud's?)

The large bump is not related to Raynaud's; it is calcinosis. Raynaud's and calcinosis are both symptoms of CREST Syndrome, which is a form of systemic scleroderma.

Severe cases of systemic scleroderma and Raynaud's (as well as other illnesses) may cause a total lack of blood supply to the extremities. When this happens, necrosis (death of tissue) and gangrene may set in, sometimes making it necessary to have the affected part(s) amputated.

Raynaud's and gangrene sets in more frequently among scleroderma patients who smoke or use caffeine, because such substances further constrict blood vessels. (Also see: Raynaud's Prevention)