Common myth calls it an unavoidable consequence of adolescence and mistakenly links it to eating chocolate and greasy foods. Yet acne need not be the bane of teen-agers any longer, dermatologists say, thanks to an arsenal of treatments and a better understanding of the anatomy of pimples.

"Today, no teen-ager need have acne," Dr. Stanley Hurwitz, professor of dermatology and pediatrics at Yale University School of Medicine, told participants at the annual spring meeting of American Academy of Pediatrics earlier this month. "We have the medications that we need to fight acne . We know exactly how to utilize them. Even the most severe cases can be controlled."

Among the more recent acne-fighting medications are benzoyl peroxide, topical antibiotics and ointments containing vitamin A. For severe cases, there are oral antibiotics, while the very worst cases may be helped by the prescription drug Accutane.

Accutane is a powerful drug, one that can cause birth defects as serious as thalidomide caused. It is not recommended for women who are pregnant or who may become pregnant, and it is advised that women who have taken Accutane stop the drug for at least a month before becoming pregnant.

These medications work by halting the development of pimples inside the skin rather than on its surface. They break up the cell formation clogging oil ducts, and allow the build-up of oil to be flushed away. They also fight bacterial colonies that thrive inside these blocked ducts and cause further inflammation.

Acne develops not in pores but in the canals or oil ducts located about one-eighth inch beneath the surface of the skin. "For years we misunderstood it," says Hurwitz. "We thought that it was dirt and oil clogging the pore."

Oil ducts are often blocked by cells that have been shed from the lining of the duct. This produces microscopic whiteheads inside the skin. These whiteheads "are not perceptible," Hurwitz says, but they are like a time bomb -- they eventually grow and burst, letting oil escape inside the skin.

When that happens, the oil acts as an irritant and triggers inflammation. "The body tries to compensate by sending white blood cells to the rescue," Hurwitz says. But that only makes matters worse. The result is pimples and in severe cases painful cysts that often wound the psyche and frequently mar the skin with permanent scars.

Alcohol and other astringents can take oil off the skin and may be good for getting rid of a few blackheads. But for people with full-blown cases of acne, these treatments may actually do more harm than good. "By drying the skin," Hurwitz says, "the ducts may counteract the process by producing more oil."

It takes these newer treatments to get to the source of the acne, experts say. The standard course of treatment begins with benzoyl peroxide soaps and gels bought over the counter. These products should be tested in small amounts on the inside of the wrist, experts say, since about 1 percent of people are allergic to them. If after six to eight weeks of use the pimples persist, experts recommend consulting a dermatologist.