Pimples, zits, blemishes--acne is the most common skin disease in the United States. Between 17 million and 45 million people have some form of acne, the University of Maryland Medical Center says. It exists in many forms and can develop in many places. One common type of acne is blackheads, which frequently develop on the back.
Hormones are the primary cause of blackheads on the back. When hormones surge, says the American Academy of Dermatology, the body produces more sebum, which is the oil produced by the sebaceous glands to lubricate hair and skin. The sebum clogs hair follicles, which sometimes close and form a closed comedo, or whitehead. When the clogged pore stays open, the oil darkens; this is called an open comedo, or blackhead. Oilier parts of the body, including the upper back, are more prone to the different forms of acne, including blackheads.
Friction from tight clothing and backpacks can cause acne outbreaks. Acne mechanica is a type of acne caused by heat, constant pressure and repetitive friction, says the American Academy of Dermatology. If you've been on a long hike with a backpack, for example, you may discover an outbreak of blackheads on your back. People who have a predisposition to back acne are more likely to develop acne mechanica.
Though there are many advertisements for cosmetics that are oil-free and non-acne-producing, you might not think that’s a concern when it comes to your back. But oil-based moisturizers or sunscreens can clog pores as well, so the American Academy of Dermatology recommends using products labeled “non-comedogenic,” or oil-free. In people with longer hair, hair products can be a concern as well. In the event the hair touches the back, products in the hair or even oily hair itself can trigger a breakout.
Your family history and genetics may be responsible for the blackheads on your back. The CNN Health website says that a family history of acne is a risk factor. If your parents were prone to acne, you probably will be as well.