My doctor's first diagnosis on me was Ankylosing Spondylitis, because in the blood work I was positive for the HLA-B27 marker. Then he went to Psoriatic Arthritis because I had a small patch of psoriasis at the back of my scalp. Then he mentioned Fibromyalgia, and I can't remember what else. We do know I've got Osteoarthritis, but there's also one, two or 3 other different things along with it, which he just calls "Rheumatism", so I'm going with RA, since he won't come right out and call it that. Peripheral Spondylitis I have not heard of. I hope you are able to get the treatment that you need.