Back acne, also known as "bacne," refers to acne that appears on the back. Like acne on the face, back acne can manifest in various forms such as pimples, blackheads, whiteheads, cysts, or nodules.

It occurs when hair follicles become clogged with excess oil (sebum), dead skin cells, and bacteria.

Factors such as hormonal changes, genetics, certain medications, sweating, and friction from clothing can contribute to the development of back acne.