Acne is a common, chronic skin condition caused by inflammation of oil-producing sebaceous glands. Acne usually begins between the ages of ten and thirteen, and persists for five to ten years. Acne breakouts are most common on the face, but they can also occur on the back, shoulders, neck, chest, scalp, upper arms and legs.

Young men and women get acne in equal numbers. Younger males are more prone to severe, longer-lasting forms of the skin condition. Many women suffer from "hormonal acne" — their outbreaks are tied to the hormonal changes related to their menstrual cycle. While hormonal acne typically starts between the ages of 20-25, it can strike teenagers as well. Hormonal acne is sometimes persistent in women in their 30s.

In adolescents, acne breakouts are related to the natural release of androgen hormones, which occur during puberty. Acne can also be caused by the use of harmful, body-building steroid drugs. Humidity and perspiration can also contribute to breakouts. Contrary to earlier belief, acne is not affected by diet or poor hygiene. In fact, over-washing can make an acne flare-up harder to control.

Even though teenagers tend to call any form of a breakout a "zit," acne has more than one symptom. A build-up of P. acnes can cause:

• Blackheads and whiteheads, also known as comedones; comedones are enlarged pores filled with sebum. Blackheads are comedones that have opened onto the skin surface. Whiteheads are comedones that are closed on the surface.
• Pimples, also known as pustules; these inflamed follicles occur when the P. acnes bacteria in the follicle attracts infection-fighting cells. The follicle may rupture, spilling its contents into the surrounding skin, causing further inflammation.
• Nodules and cysts, which are more severe forms of acne that go deeper into the skin, forming firm, deep bumps and swellings; similar to pimples, they result from increased sebum production, which leads to bacterial growth, irritation and redness.

When left untreated, or when "picked at," acne lesions can lead to permanent scarring.

Continue to: Teen Acne