Suggest Remedies For Fleshy Bumps On My Back And Chest

I have little fleshy bumps that came up on my upper back and chest after wearing a new shirt. I did not wash it first which I probably should have but I have never had a reaction like this before. I also thought it might be due to my new body wash or detergent but its ONLY on my back and chest. How can I get rid of this and what is it?