While patients with mild-to-moderate acne have been shown in studies to respond well to treatment with blue or red light-emitting diode (LED) devices, new research indicates results might be better with combinations of light colors with photodynamic therapy (PDT).
Especially blue and red LED devices shine in acne treatment, according to James Swan, M.D., dermatologist, professor of medicine (dermatology), Loyola University Medical Center, Maywood, Ill., and senior author of a review and clinical experience on light-emitting diodes published June 2015 in the Journal of Clinical and Aesthetic Dermatology.1
“There are a number of non-laser light devices, and some are used as solo, light only, and some are used as part of a photodynamic therapy treatment with levulinic acid or other photo-sensitizers,” Dr. Swan says. “Results vary somewhat. Blue light is probably the first one to be used and has some moderate benefit. Red likewise has benefit. LED treatments seem to work better when red and blue are used together and even better when combined with photodynamic therapy. But they all work; red, separately, blue, separately,” he says.
There are new devices that combine red and blue light. Blue LED light, 400nm to 470nm, is best suited to target P. acnes in acne vulgaris, according to the review. Studies looking at patients treated with blue LED devices for mild-to-moderate acne suggest the device type reduces lesion counts by 50 to 60 percent and even clears patients, as well as reduces lesion size and erythema. Treatment regimens vary, and included 8-, 10- or 20-minute blue LED (415 nm) treatments over four weeks, as well as two weekly 20-minute treatments for four to eight weeks. Combining blue LED treatment with aminolevulinic acid (ALA) didn’t seem to improve results but did increase side effects. 1
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While the review did not look specifically at acne treatment with red LED devices, which penetrate tissue deeper than other visible wavelengths, Dr. Swan says that red LED (like blue) effectively targets P. acnes. But acne treatment efficacy improves with combination blue (415nm) and red (640) LED devices. This includes the use of at-home combination devices, which in one study decreased inflammatory acne lesions by 77 percent and noninflammatory lesions by 54 percent. 1