79 Year Old Female Having Purple Blotchy Shin Changes On

79 year old female having purple blotchy shin changes on lower left leg and foot; comes and goes. Swelling, redness and pain in wrists and hands. Left side worse. Is on furosemide 40 mg/day and potassium 750 mg/day for the swelling. Had blood in stool sample. Could the potassium be the cause of the purple blotchy skin and bleeding? What is another alternative to the furosemide to avoid taking the potassium?