Blue light
However, in a 2007 study of 22 patients with moderate to severe acne randomized to one of three ALA-PDT treatments – intense pulsed light (IPL; 600-850 nm), a combination of IPL (580-980 nm) and bipolar radiofrequency (RF) energies, or blue light (417 nm) – in three sessions at 2-week intervals, ALA-PDT with activation by IPL yielded the most consistent, lasting improvement in moderate to severe acne (J. Drugs Dermatol. 2007;6:1010-6).
In a study of 60 volunteers with facial acne (grades II and III), de Arruda et al. compared the safety and efficacy of blue light to topical benzoyl peroxide 5% over 4 weeks. Thirty patients received blue light treatment twice a week, and the other 30 self-applied the topical formulation twice daily. The improvements were similar in both groups, but side effects were milder in the blue light group (An. Bras. Dermatol. 2009;84:463-8).
Choi et al. compared the bactericidal effects of 5-aminolevulinic acid (ALA) with blue and red light on P. acnes and found that blue light was more effective than red light phototherapy in eliminating the bacteria unless ALA was added, which substantially augmented red light phototherapy efficacy (J. Dermatol. 2011;38:661-6).
In summarizing the off-label uses of light-based treatments and PDT using topical precursors of porphyrins, Sakamoto et al. observed that blue light alone lessens acne severity due to anti-inflammatory effects; PDT using 5-ALA or ALA derivatives provides antimicrobial and anti-inflammatory activity; and, at high doses, red-light PDT may suppress or eradicate sebaceous glands, yielding clinical improvement (J. Am. Acad. Dermatol. 2010;63:183-93).
Combination therapy
In 2011, Wheeland and Dhawan assessed the efficacy and tolerability of treating mild to moderate facial acne using a novel, handheld, light-emitting diode (LED) blue-light device, along with a foam cleanser containing 5% glycolic acid and 2% salicylic acid, plus a serum containing 1.25% salicylic acid, 0.5% niacinamide, 0.08% liposomal-based azelaic acid, and superoxide dismutase. In all, 28 of 35 adults aged 25-45 years completed the 8-week study, in which they used the device twice daily (in addition to the cleanser before treatments and the serum after nighttime treatments). Significant reductions in inflammatory lesion counts were seen from week 1 onward, and significant reductions in noninflammatory lesion counts were seen from week 4 onward compared with baseline counts. The number and severity of flares were significantly reduced from baseline as well.
Therapy was well received by patients, with more than 90% claiming improvement in overall skin appearance and other parameters. In addition, 86% described the treatment as gentler than other therapies. (J. Drugs Dermatol. 2011;10:596-602).
Products
The Skin Clarifying Blue Light device has a power density of 400 mW/cm2, which is 10 times the power of other LED acne devices. This high power density allows the Skin Clarifying Blue Light device to deliver high levels of efficacy with short treatment times. When used as stand-alone treatment, it delivered a 70% reduction in inflammatory lesions in 8 weeks. The success of products designed for self-administration has coincided with the rampant interest in the creation of smart phone applications (J. Cosmet. Laser. Ther. 2011;13:308-14; J. Clin. Aesthet. Dermatol. 2009;2:40-4; J. Clin. Aesthet. Dermatol. 2009;2:44-50). That is, blue-light therapy apps have been developed for the iPhone and the iPod touch. None, however, has been approved by the Food and Drug Administration, although at least one is said to be under investigation in a clinical trial. I am skeptical about the efficacy of these LED-backlit apps and concerned about potentially prolonged magnetic radiation exposure that would be required. The self-administered devices appear to be a more reliable alternative.
Conclusion
Blue light can effectively be used to treat mild to moderate acne by causing photodynamic destruction of P. acnes. It can be used alone or in combination with topical or other light regimens. Additional studies are needed before a consensus protocol can be established, and future research goals should include establishing the optimal incubation time, activating light source, and frequency of treatment.
Dr. Baumann is in private practice in Miami Beach. She did not disclose any conflicts of interest. To respond to this column, or to suggest topics for future columns, write to her at sknews@frontlinemedcom.com.
