Could be gluten/ wheat intolerance.
It’s called Keratosis Pilaris – a very common skin condition that causes acne-like bumps (resembling goose bumps) from a build up of keratin, a natural protein in the skin.
Because keratosis pilaris is an inflammatory disorder, anything you can do to reduce inflammation is going to help a great deal – take fish oil, avoid sugar.
Don’t scrub (it doesn’t get to the problem which isn’t on the surface). If anything, scrubbing further inflames skin.
Try reducing/eliminating refined carbs/wheat in your diet – and voila, you’ll find that they disappear!!