Background: Available topical treatments are slow and frequently irritating. Oral therapies may be associated with increased bacterial resistance (antibiotics) or possible severe side effects (oral isotretinoin). In vitro and in vivo exposure of acne bacteria to 405-420 nm ultraviolet (UV) free blue light results in the photo-destruction of these bacteria through the effects on the porphyrins produced naturally by Propionibacterium acnes. A novel, high-intensity, narrow band 420 nm UV free blue light has been shown to decrease inflammatory acne lesions after eight bi-weekly treatments.
Objectives: To examine the effects of high-intensity, narrow band 420 nm UV free blue light (ClearLight) on inflammatory acne lesions.
Methods: Three studies were carried out to examine the clinical effects of high-intensity, narrow band blue light on papulo-pustular acne: the split-face dose-response study, the full-face open trial and the split-face, double-blind controlled study. The studies enrolled 10, 13 and 23 patients respectively.
Results: The data show more than an 80% response to 420 nm acne phototherapy with a significant reduction of 59-67% of inflammatory acne lesions after only eight treatments of 8-15 minutes. The reduction in lesions was steady in the follow-ups at 2, 4 and 8 weeks after the end of therapy. Prolonged remission was evident in the 8 weeks after the end of therapy. No adverse effects or patient discomfort were noted in any of the patients.
Conclusions: Acne phototherapy by high intensity, narrow band 405-420 nm light is proven to be an attractive, fast, effective, non-invasive alternative to current topical and parenteral anti-acne remedies.