Does Severe Itching On Breasts And Underarms Indicate Psoriatic Arthritis?

I have severe itching on both my breast. I also have severe itching under my arms. My breast and under arms are clear of any rashes, sores and discolorations. The nipples do not leak. I have Crohn's disease that has been in remission for approximately seven years. Also, I have osteo arthitis and fibromyalgia. I was wondering if I might be getting psoriatic arthritis. I only thought of this because my sister and neice have been diagnosed with it. The itching is so bad that I bruise myself. I have been doing this for over a year. I started developing itching all over my entire body. I use unsented everything, soap, deorderant, detergent, dryer sheets, etc. I no longer itch everywhere, just the breast and underarms. It never dawned on me that this could be a sign of something bad. I just assumed I was allergic to something topical. I will be going for my annual checkup within the month and I will discuss this with my doctor. I am planning on seeing an allergist. Do you have any suggestions that might help.