Keratosis pilaris is a common, harmless skin condition that causes small, rough bumps, often on the arms, thighs, or cheeks. It happens when dead skin cells clog hair follicles, leading to a bumpy, sandpaper-like texture. Though it’s not painful or serious, moisturizing and gentle exfoliation can help smooth the skin. It often improves with age and is sometimes called “chicken skin” due to its appearance.