What are the little white bumps on the back of my arm?

This is called keratosis pilaris and it is most often found on the upper arms, buttocks and thighs and cause some reddish white bumps that feel rough and dry. You will notice this problem more in the winter because low humidity causes more clogged pores. Try an exfoliation product or an alpha and beta hydroxyl acid peel along with intensive daily moisturizer. Try dermadoctor KP Double Duty or L'Oreal ReFinish Chest, Arms and Hands MicroDermabrasion kit. link....