A safe and effective yellow light-emitting diode treatment for mild to moderate acne: A within-patient half-face dose ranging study, Chris Edwards, PhD, Stephanie Hill, Alexander Anstey, MD, Royal Gwent Hospital, Newport, United Kingdom
Previous studies have shown that blue light phototherapy can improve mild to moderate acne. One proposed mechanism for action of visible light in acne is an effect on endogenous porphyrins in Propionibacterium acnes (P acnes). Intense yellow light around 585 nm should penetrate deeper than blue light and will also activate the porphyrins in Pacnes. This study assessed the safety and efficacy of an acne treatment using a light-emitting diode (LED), a cheaper and safer (than laser) high-power light source for dermatological use.
Thirty subjects with mild to moderate facial acne were treated twice a week for 4 weeks. Each side of their 2 face received one of 3 doses of yellow light: 3.0, 1.5, and less than 0.1J/cm (sham) in an incomplete blocks design such that each treatment dose was compared with each other dose within patients for 20 patients. Main outcome measures were numbers of adverse events (to assess safety), Leeds acne grading, lesion counts, Dermatology Life Quality Index (DLQI), and patient and investigator global assess- ment of improvement. Assessments were made before and immediately after the treatment and at 2, 4, and 6 weeks after treatment. No adverse events were recorded.
The highest dose resulted in a 27% improvement in Leeds acne score immediately after treatment (P = .05), which remained at the 6-week assessment (23%, P = .05). Total lesion count decreased by 49% immediately after treatment (P<.001) and was 21% less at 6weeks (P<.07). DLQI improved by 36% immediately after treatment (P = .004) and was still improved by 21% at 6 weeks (P = .03). Standardized color photographs were independently assessed by 3 dermatologists.Seventy-seven percent of assessments of preimage compared with immediately postimage judged that the high-dose treatments had improved the appearance of acne. We conclude that intense yellow light is a safe, well-tolerated treatment for mild to moderate acne.
Author disclosure: Presenting author has funding to attend this AAD meeting. Supported by Enfis Ltd.Poster Discussion Session P105, American Academy of Dermatology, 64th Annual Meeting, March 3-7 2006, San Francisco.Supplement to Journal of The American Academy of Dermatology, March 2006, Volume 54, Number 3.