I feel like i got an itch under my skin top right shoulder, like when i move it or walk it feels itchy under it, workout injury? something else?

Possible nerve : If it is an isolated itch with no associated rash it may be related to a nerve irritation. A peripheral nerve which normally performs a sensory function to a specific area of the skin can sometimes malfunction and create an area of intense itching in that area. It is benign but annoying and usually resistant to antihistamines. Other compounded topicals or pressure with taping may help.