Acne FAQ • What Is Acne? • How Does Acne Develop? • What Causes Acne? • Factors That Can Make Acne Worse • How Is Acne Treated? • Treatment for Blackheads, Whiteheads, and Mild Inflammatory Acne • Treatment for Moderate to Severe Inflammatory Acne • Treatment for Severe Nodular or Cystic Acne • Other Treatments for Acne • How Should People With Acne Care for Their Skin? • What Research Is Being Done on Acne? • Why Acne Forms, and How Accutane Knocks It Out • Where Can People Find More Information on Acne?

Acne is the most common skin disorder, and while it usually appears in adolescence, adults can get it too. Acne occurs when hair follicles and the sebaceous glands inside the follicles are inflamed. Sebaceous glands make an oily substance called sebum. Too much sebum can clog the follicles and lead to bacterial growth and inflammation.

According to the American Academy of Dermatology, the four basic mechanisms contributing to acne are hormones, increased sebum production, changes inside hair follicles, and bacteria. Acne usually occurs at age 11 to 14 when the body starts producing male hormones called androgens. Androgens can over-stimulate sebaceous glands and make them produce more sebum.

Dead cells inside hair follicles normally are shed and come out onto the surface of the skin. But in people with acne, the cells are shed faster, stick together, mix with sebum, and clog the follicle. Then bacteria contaminate the skin cell and sebum mixture and grow. When the body's immune system tries to destroy the bacteria, inflammation results.

Accutane helps the function of the follicles return to normal, lowers production of sebum, slows the growth of a bacterium called Propionibacterium acnes (P. acnes), and reduces inflammation and the chance for scarring. The drug is unique in its ability to affect all main underlying causes of acne formation.

Acne begins in pilosebaceous units, which consist of sebaceous glands and a single hair follicle. The sebaceous glands produce an oily substance called sebum.

Sometimes, hormones produced in the adrenal glands trigger the production of excess sebum, clogging the follicle and leading to bacterial growth. The resulting plug can appear dark and is called a blackhead, or open comedo.

If the plug is below the skin surface, it is called a whitehead, or closed comedo.

But, if the pocket of sebum and bacteria becomes too large, the follicle will rupture, spilling its contents into the surrounding tissue. These tissues are damaged when the body's immune system attempts a repair, resulting in a papule, pustule, cyst or abscess.

Source: FDA/Office of Public Affairs.