Overview

Acne affects almost every teen; the American Academy of Dermatology reports that some 85 percent get pimples. Although many use over-the-counter topical preparations to treat their acne, those with moderate and severe acne may consider light treatments.

Causes

Acne has several interrelated causes, according to the Mayo Clinic. In most teenagers, hormonal surges overstimulate the skin's sebaceous glands, which produce sebum oil to lubricate the skin. The excess oil combines with rapidly shedding skin cells to clog pores. Once a pore is clogged, forming a whitehead or a blackhead, bacterial infection sets in, causing inflammation.

Function

Acne light therapy uses blue LED lights, targeted in a narrow bandwidth, on the affected skin. The blue lights penetrate the skin and kill the bacteria that cause inflammatory acne. But blue light therapy does not appear effective on nodulocystic acne, a severe type of acne that involves cysts under the skin, according to the American Academy of Dermatology. The U.S. Food and Drug Administration has approved acne light therapy, but many dermatologists reserve it for patients who have not seen success with other treatments.

Time Frame

Acne blue light therapy involves a series of closely spaced treatments over several weeks, according to the American Academy of Dermatology. In most cases, dermatologists recommend treatments twice a week over one month. The treatments themselves take about 15 minutes each, and side effects, which include reddening of the skin, swelling and dry skin, tend to be minor.

Research

Medical research backs the use of blue light therapy in acne treatment. For example, a study published in the Journal of Cosmetic Dermatology in September 2008 looked at 21 patients with mild to moderate facial acne. All patients received sessions twice a week for four weeks. The researchers reported that both inflammatory and noninflammatory acne lesions improved significantly, and the patients' appearance also improved.

Considerations

Although studies show that blue light therapy treats acne in the short term, the American Academy of Dermatology warns that long-term studies haven't been done. In addition, because acne light treatment only targets one facet of acne's causes--bacterial infection--your dermatologist likely will recommend using topical medications that target other acne causes in addition to light therapy.