Pustules are well circumscribed elevations of the superficial layers of the epidermis. Like papules, they may be follicular or interfollicular in distribution. The most common cause is bacterial infection, where the pustules are filled with neutrophils, bacteria, debris, and possibly a few loose keratinocytes (acantholytic cells). It must be kept in mind that pustules, due to the thinness of the epidermis are usually transient. What is often observed is a transition from erythematous macules to papules to relatively few pustules to small crusts and scale.

small, inflamed, pus-filled, blister-like lesions on the skin surface. Pustules on the skin surface are relatively common occurrences. Pustules are common in acne and are the yellowish topped small, pus-filled lesions that adolescents are notorious for picking and squeezing.

Pus-filled pimples.