I Have A Rash On My Stomach And Legs That

I have a rash on my stomach and legs that I have had for about 2 mths now. I've had it before several years ago. I was treated with many prescription creams and 2 cortisone shots, I also took100 mg of prednisone daily. After no improvement I seen an iridologist who told me my liver was black and needed a liver cleanse to get rid of the junk that was backing up. I proceeded to do as he said with herbal treatments , bathing daily in vinegar and peroxide and was cleared up in about two weeks. My question is what would cause this to be happening? He said I was in chemical over load.