Bacne

Bacne is informal shorthand for acne on the back, and in everyday use the term often stretches to cover the shoulders and chest. The mechanism is the same as facial acne — pores blocked by dead cells and sebum, with resident skin bacteria and inflammation involved — but the skin on the back is thicker and carries larger, more numerous oil glands, so lesions can be deeper and slower to settle.

Friction and sweat make it worse. Backpack straps, sports bras, tight synthetic tops and long hours in damp gym clothing all contribute, and showering promptly after sweating, then changing out of wet layers, helps more than most people expect. Conditioner and styling product rinsing down the back is another common trigger.

Over-the-counter routes usually involve salicylic acid or benzoyl peroxide body washes and long-handled sprays that reach the area — note that benzoyl peroxide bleaches fabrics and towels. Both can dry and irritate at first, so build frequency up slowly and keep treated skin covered or protected in strong sun. Deep, painful or scarring lesions, and anything that has not improved after a couple of months, belong with a dermatologist. Picking makes marks last longer.