Similar to whiteheads, these superficial pimples form on the lips, chin and nostrils when pores become clogged. These papules are pores containing sebum and bits of keratin. Each pore has a sebaceous gland that can be emptied. Once sebum mixes with dead skin cells and keratin fragments or proteins from the epidermis, it produces knobs that resemble whiteheads. People with oily skin tend to have more of these pimples because more sebum accumulates in the pores.
These baby whiteheads are more superficial than traditional whiteheads and often spread through wrinkles in the skin. These are common around the nostrils and in the chin folds as it is where oil is collected and placed throughout the day. Creases can also cause friction, and anything that causes skin friction can cause acne because the pores are irritated. That said, no matter how often you try to pop these pimples, they're likely to change depending on their location. Sometimes we just have pore problems and can flare up in the same area over and over again.