Pimples Past Puberty

What’s going on

Acne begins when glands at the base of hair follicles secrete too much sebum, an oily substance that lubricates the skin. Excess sebum, along with dead skin cells, can clog the follicles causing whiteheads or blackheads. If bacteria on the skin invade the clogged follicles, the follicle wall can rupture, resulting in redness and inflammation—that is, a red pimple.

Teens develop acne when a flood of hormones causes the oil glands to go wild. What triggers this cascade of events in adults is less clear, but besides genetics, hormonal changes remain a leading culprit. This explains why many women have acne flare-ups prior to their menstrual periods and during pregnancy. Some women experience acne for the first time, or a worsening of it, at menopause. Certain medical conditions may cause hormonal imbalances as well. Blemishes are also blamed on resistant bacteria, cosmetics, and some medications; emotional stress, climate changes, too little rest, and smoking may be other factors.

What about diet? Despite persistent beliefs, a diet-acne connection has never been proven. Studies have failed to show that even large amounts of chocolate trigger acne outbreaks. Same goes for French fries and other greasy foods.

While the role of diet in acne is controversial, emerging research suggests that avoiding high-glycemic carbohydrates may help. Such foods are quickly broken down into sugar in the blood and raise insulin levels, which in turn may increase production of hormones implicated in acne. In a 2007 study in the American Journal of Clinical Nutrition, young people who ate lower-glycemic foods (such as whole-grain bread and certain fruits) had less acne after 12 weeks, compared to those who ate a lot of refined grains and sugary foods.

When to seek treatment

Adult acne is usually mild and tends to clear up on its own or with a little self help (see below). But if it persists or develops suddenly, see your doctor or dermatologist. Mild-to-moderate cases are usually treated with topical medicines (they may contain benzoyl peroxide, antibiotics, retinoids, and other ingredients); oral medications (including antibiotics) may help in more severe cases. What works for teens generally works for adults, too, although adult skin may be both more sensitive and more resistant to various ingredients. A dermatologist may also do light therapy, chemical peels, and gentle extractions. If hormone imbalance is a factor in a woman, oral contraceptives or an anti-androgen may be prescribed. The drug isotretinoin (Accutane) is very effective for scarring acne, but it has serious side effects and must not be taken by pregnant women or women who could become pregnant during treatment; it’s safe to become pregnant a month after you stop the drug.