Clinical And Antibacterial Efficacy Of High Intensive Narrow Band Blue Light On Acne Vulgaris

Objectives To explore the bacterial etiology of acne vulgaris and to assess the antibacterial efficacy of high intensive narrow band blue light on acne vulgaris in vivo and vitro. Methods Patients with mild to moderate acne were divided into two groups at random: studied group and control group. Studied group was treated by high intensive narrow band blue light (405-420 nm, ClearLight^TM, LUMINUS) combined with Chinese traditional medicine: DotClear (?), while control group solely by DotClear (?). Lotio alba was applied topically in both groups. Bacteria were cultured before and after the treatment. Main kinds of bacteria isolated from the acnes got the irradiation from blue light. CFU (colony forming units), morphology and ultrastructure of the bacteria irriated by the blue light were observed. Results The data showed that the phototherapy group got more significant reduction rate compared with control group. Differences in mean percentage improvements for 2 weeks and 4 weeks between groups were 18.8% (95%CI 10.7²7.0%) and 27.0% (95%CI 19.3³4.8%) . After 2 and 4 weeks, the differences in mean percentage improvements in inflammatory lesions between treatments were 15.2% (95%CI 4.8²5.5%) and 13.3% (95%CI 3.1²3.4%) , and thatin comedones between groups were 18.0% (95%C710.3-25.8%) and 32.8% (95%C7 22.9-42.8%) . There was no difference on adverse effects between groups. P. acnes (32.4%), P. granulosum(6.9%), S. epidermidis(35.3%), S. aureus(4.9%), S. heamolyticus (7.8%) , S. cohnii (1.0%), Corynebacterium 5^.(9.8%), Kpeumoniae(\.0%) and B group Streptococci{\.0%) were isolated from the acne patients. The bacterial cultures showed that P.acne disappeared in 64.7% studied and 25% control patients. In vitro investigation revealed that irradiation from this light source reduced CFU of P. acne and S. epidermidis. The bactericidal rate to P. acnes was 82.2%. And the bactericidal rates to P. granulosum, S. epidermidis and 5". aureus were all higher than 50%. Conclusions High intensive narrow band blue light has proven to be an effective antibacterial method to both inflammatory and non-inflammatory acne lesions. Blue light combined with Chinese traditional medicine provide us a new attractive way to treat acne.