I have rash up my legs that look to be purpura, i have gone to doctors 4 times now and still don't have diagnosis, it went away and came back. ideas?

Vasculitis: This may be an autoimmune vasculitis where small blood vessels in the skin(capillaries) rupture and leak blood. Since only your lower legs are involved, a rheumatologist or hematologist is qualified to evaluate,advise and treat you. Appropriate tests will be ordered. If you had generalized purpura, a blood dyscrasia would be likely and a hematologist would then be recommended instead.