I'm just having severe pain on my left shoulder back area ..as if you take your right hand and pat yourself on the left back shoulder..it's chronic non stop pain throbbing and is so painful..no redness or swelling I can see or feel..just bad pain. I had a mild pinkish itchy rash on my left lower back over New Years whuch was there fir approximately 2 weeks and couldn't get in to a doctor. Then rash subsided but pain started in shoulder..i have a dermatology appt this Tuesday..Im.hoping someone can diagnose me because I'm I'm severe pain. I read that PMR comes on suddenly ..5 days of severe pain chronic ..so far.