Systemic sclerosis is a form of scleroderma. There is information on Scleroderma.org or you can google scleroderma and look for the nih (national institute of health) site.
It's an autoimmune disease like lupus but manifests differently. As with lupus, scleroderma can affect only the skin or it can potentially affect other organs. Systemic means that it can be spread throughout the body. It's treated with some of the same meds as lupus.
Don't let all the information scare you. I have systemic lupus (SLE) but am in remission, so just because lupus or scleroderma can be very serious, in many cases they very manageable. Educate yourself by reading, but only your doctor can answer specific questions about your situation.
A scleroderma forum will connect you with other people who will be more knowledgeable about it than most of us here, and you may find a link to one on Scleroderma.org.
That said, hang around here if you're able to get the support you want and need. Everyone is welcome here!
SLE, fibro, renauds, restless leg?