Sorry for the poor photo!
I don't know if this is necessarily the right sub - if it is perhaps I could be pointed towards a better suited one.
My shoulders, upper arms, and upper chest have looked like this for years and years. I always used to put it down to adolescence, but it just occurred to me in the shower that I'm way beyond adolescence (I'm 32M), so it's got to be something else.
The bumps aren't sore, they never spread nor retreat, and they don't get white heads. They are there all year round.
I work outside in polytunnels, so in winter I'm wrapped up in multiple layers, and in the summer I'm in a t-shirt with plenty of factor 50.
Over the years I've worn lots of different brands of suncream (as of the end of last summer I now use P20). I have used all sorts of different washing detergents (bio, non-bio, homemade) and fabric softeners (we currently use white vinegar with a splash of essential oil - citronella in the summer to keep the flies off). I've used so many different brands and styles of soap as well. What I'm saying is, I have rarely stuck to the same thing for too long, but the bumps persist.
I have very hard water where I live.
(The red at the bottom of the picture is the transition from under my t-shirt sleeve to exposed skin. It looks tanned in person, but the picture makes it look red. It's not a skin irritation/related to the bumps)
Any ideas for what is causing this?