Acne is a skin problem that affects almost all teenagers. The condition results from the action of hormones on the skin's oil glands (sebaceous glands). The sebaceous glands make an oily substance called sebum that empties onto the skin surface through the hair follicle opening (pore). The mixture of oil and cells allows bacteria that normally live on the skin to grow in the follicle openings. When this happens, pores become clogged and pimples develop.

Pimples can be one of the following kinds:

• Comedones: Non-inflammatory papules that can be open (blackheads) or closed (whiteheads).
• Papules: Lesions that are inflamed and can be tender to the touch. These usually appear as small, pink bumps on the skin.
• Pustules (pimples): Lesions that are inflamed and filled with pus. They may be red at the base.
• Nodules: Solid lesions that are large, painful, and lodged deep within the skin.
• Cysts: Pus-filled lesions deep under the skin. These may cause scarring and pain.

In most cases, pimples occur on the face, neck, back, chest, and shoulders. Acne does not present a serious health risk, but severe acne can result in permanent scarring. In addition, acne can have significant physical and psychological consequences, such as causing a poor self-image, social inhibition, and anxiety.

Why Do Some People Get Acne and Others Don't?

It is not clear why some people are more prone to acne than others. The exact cause of acne is not known, but one important factor is an increase in male sex hormones called androgens. Androgens increase in both boys and girls during puberty. Androgens cause the sebaceous glands (oil glands) to get larger and produce more sebum. Androgens also can increase because of hormonal changes related to pregnancy or starting or stopping birth control pills.

Another factor in the cause of acne is genetics. Researchers believe that the tendency to develop acne can be inherited from parents. In addition, some drugs (for example, anti-epilepsy medication, prednisone, androgens and lithium) are known to cause acne. Cosmetics that have a greasy consistency may change the cells of the follicles, causing them to stick together and resulting in a plugged pore. Water-based products are less likely to cause acne.

Things that can make acne worse include:

• Friction caused by leaning on or rubbing the skin; harsh scrubbing
• Picking or squeezing blemishes
• Pressure from bike helmets, backpacks, or tight collars
• Changing hormone levels in adolescent girls and adult women two to seven days before the start of the menstrual period
• Stress

Other factors that were previously thought to make acne worse do not seem to have an effect on the development of acne. These factors include chocolate, greasy foods, and dirty skin.

Acne Treatments: A Host of Solutions

During the past decade, the number of acne treatments has expanded greatly, according to the American Academy of Dermatology. Among the significant advances:

• Newer topical products such as retinoids such as Tretinoin (derived from vitamin A), help unplug follicles. Although retinoids can irritate skin, new ones are made for different types of skin and promise to be less irritating.
• Combination treatments are becoming more common, with many doctors prescribing a topical retinoid together with a topical antimicrobial or an oral antibiotic to fight bacteria. Combination creams, putting ingredients such as the cleansing agent benzoyl peroxide and the antibiotic clindamycin in one product, are more common.
• Prescribing oral contraceptives for teenage girls with acne is becoming more accepted. At low doses, some types of birth control pills may help clear acne.
• Oral isotretinoin (or Accutane) can help in severe cases that haven't responded to other medications. Because the drug has been associated with depression and suicidal thoughts, patients who use it are closely followed for any changes in mood. Blood tests monitor any potential adverse effects, such as elevated cholesterol levels.