Below is an instruction from Human. Write a response.
    ### Instruction:
    How to diagnose CREST syndrome ?
    ### Response:
    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.
    