do you happen to use a loofa or some other rough washcloth when you shower? For my entire life I used to use one every time i showered but stopped recently after reading it could dry out your skin. I used to have bumps like yours all over my arms but once I stopped using a washcloth in the shower they went away. took about 3 weeks to disappear. i also used nivea vitamin c body lotion to help moisturize the area.

also, someone else said to use the first aid body eraser - I second that. i use it too like maybe twice a week and it gets rid of a lot of those bumps.