@karenll that’s great to hear. It’s important to understand your skin isn’t actually itchy. Like sciatic pain of the leg, it originates at the lower spine when spinal disc bulges contacting the sciatic nerve sending messages to the brain. The brain interprets it as pain (in some cases). I had this and mine felt like my whole leg hurt. But later became foot pain. Nowadays (decades later) my big toe hurts and I get on my inversion table for traction.
Brachial nerve in the neck heading over the shoulder and down the arms gets touched by cervical spinal disc (probably bulging from poor posture). The stretch gives the disc a chance to pull back into place. When it does the brain stops getting the information (arm is itchy).
Others like my wife have the same but hers causes pain over the shoulder and down the arms gets touched. The stretch helps her as well.
You may need to be pro active about the stretch. I do it every morning 2 x 30 seconds of hold my head up off my shoulders. While rolling my shoulders back and holding them down.
Best of luck with your recovery