Acne, in fact, is caused not by dirt or oil, but by bacteria called P. acnes that live on everyone's skin. During puberty, the body produces higher levels of androgens, which can overstimulate the skin's oil-producing (sebaceous) glands, resulting in a greater amount of the oily substance called sebum. The more sebum, the more likely it is that a hair follicle will become clogged, resulting in follicular plugs called comedones. These clogged follicles allow P. acnes to proliferate. Some people are hypersensitive to P. acnes, says Guy Webster, MD, PhD, vice chairman of the department of dermatology at Jefferson Medical College in Philadelphia. These people have excessive immune responses to the bacteria -- similar to an allergic reaction -- and this results in acne.
But hormones, too, can be the cause. According to Debra Jaliman, MD, clinical instructor of dermatology at Mount Sinai School of Medicine in New York City, some women are genetically prone to having more drastic hormone swings, higher levels of androgens, and oil glands that are more sensitive to hormones. "When hormone levels stay stable, it's easier on the skin. When they fluctuate a lot, that's when the skin breaks out." Hence, those pesky pre-period breakouts with which women are so familiar.
Studying the Pill
That's another reason some scientists believe the birth control pill and other hormone-controlling drugs can treat acne. The only birth control pill studied for this purpose is Ortho Tri-Cyclen, but according to Jaliman, any formulation that contains a low amount of androgen can be used to treat acne.
In a study published in the November 1997 issue of the Journal of the American Academy of Dermatology, researchers looked at the effectiveness of Ortho Tri-Cyclen in treating acne. Evaluating 247 women, scientists found that 93.7% of the Pill-taking group showed an improvement, while only 65.4% of the placebo group had such skin-clearing results.
Still, those results, while they sound promising, can be deceiving, says Jaliman. "Improvement does not mean total clearing. To a patient, if they're improved but not clear, they're still not happy," says Jaliman, who, in her practice, has seen mixed results with the Pill.