My mother's form was systemic, and it was horrible to watch.  Here is
some info from rheumatology.org:

http://www.rheumatology.org/public/factsheets/scler.asp?aud=prs

Found this on Mayoclinic.com...

Scleroderma (sklere-o-DER-muh) is a rare, progressive disease that
leads to hardening and tightening of the skin and connective tissues
- the fibers that provide the framework and support for your body. It
usually begins with a few dry patches of skin on the hands or face that
begin getting thicker and harder. These patches then spread to other
areas of the skin. In fact, scleroderma literally means "hard skin."

In some cases, scleroderma also affects the blood vessels and internal
organs. Scleroderma is one of a group of arthritic conditions called
connective tissue disorders. In these disorders, a person's antibodies
are directed against his or her own tissues.

Researchers haven't established a definitive cause for scleroderma.
About 150,000 Americans have the disease. It's more common in women
than in men and more common in adults than in children. Scleroderma can
run in families, but in most cases it occurs without any known family
tendency for the disease. It's not considered contagious or cancerous,
but this chronic condition can greatly affect self-esteem and the
ability to accomplish everyday tasks.