Moisturize!! Keratosis pilaris is a common skin condition that causes rough patches and small, acne-like bumps, usually on the arms, thighs, cheeks and buttocks. Keratosis pilaris bumps are usually white, sometimes red, and generally don't hurt or itch. Keratosis pilaris can be frustrating because it's difficult to treat. However, keratosis pilaris isn't often serious and usually disappears by age 30.