How to diagnose CREST syndrome ?
How is CREST syndrome diagnosed? CREST syndrome can be difficult to diagnose. Signs and symptoms vary widely and often resemble those of other connective tissue and autoimmune diseases. Further complicating matters is that limited scleroderma sometimes occurs with other autoimmune conditions  such as polymyositis, lupus and rheumatoid arthritis.   A blood sample can be tested for antibodies that are frequently found in the blood of people with limited scleroderma. But this isn't a definitive test because not everyone with limited scleroderma has these antibodies. Sometimes doctors take a small sample of skin that's then examined under a microscope in a laboratory. Biopsies can be helpful, but they can't definitively diagnose limited scleroderma either.  Along with a blood test and skin biopsy, additional tests to identify lung, heart or gastrointestinal complications may also be conducted.