Could anyone tell me what these strange bumps are?

For ages now, perhaps even a year, I have had a patch of skin on my left back shoulder (if that makes sense) that itches. If you look at it there is no rash. However, lately, I can feel bumps under my skin. It feels at times are though something is crawling under my skin? It’s starting to freak me out as lately it has been very ‘crawly’ and feels awful. It’s not easy to scratch either because of its location.
Is it a part of peri? As I am peri at the moment!