You may have pimples only along your shoulders and upper back. Or they may develop all over your back and torso down to your waist. These zits can be painful and may develop in clusters. You might have one type of pimple or a combination of: Blackheads. Cysts, which result from a type of acne called cystic acne. The cysts form bumps deep below your skin’s surface. Nodules, which result from a severe type of acne called nodular acne. Acne nodules form hard lumps under your skin. Red bumps that don’t have a “head.” Whiteheads.