Table 4.

Studies on blue light therapy for acne vulgaris

Light source	Clinical trial type	Acne type	Treatment regimen	No. of patients/acne location	Total follow-up time	outcome	Side-effects	Ref
407–420 nm metal halide lamp	open clinical trial	Mild to moderate acne	twice a week up to 5 weeks	30	during the trial period (0, 1, 3 and 5 weeks) and at 1 month after the final treatment	Acne lesions were reduced by 64%.	Two patients experienced dryness.	281
Handle 412nm LED	prospective, single-center, open-label study	Mild-to-moderate, including inflammatory or non-inflammatory	2J/cm2/day full-face treatment or 29J/cm2/day localized spot treatment, twice daily at home	32/facial acne	eight weeks	100 percent of subjects considered their overall appearance was improved, clarity (97%), radiance (73%), tone (80%), texture (80%), and smoothness (83%)	Three adverse events: minimal transient skin dryness and minimal transient hyperpigmentation	282
home use Blue-light LED	IRB approved randomized self-control study	inflammatory	Four Treatments were conducted twice daily in the clinic	30/facial acne	followed-up till resolution	significant reduction in lesion size and lesion erythema as well as the improvement in the overall skin condition controlled with the placebo	NA	283
hand-held, Blue-light LED	open clinical trial	mild-to-mode rate inflammatory acne	a daily dose of ~29 J/cm2, twice daily	33/facial acne	eight weeks	90% improvements	NA	284
407 to 420 nm LED	A prospective, randomized, open and comparative study	inflammatory acne lesions grades II or III	underwent 8 sessions of light therapy for 15 minutes each, twice a week, within minimum intervals of 48h	60/facial acne	4 weeks	The improvement achieved by the blue light was the same as the one with benzoyl peroxide	23.3% patients with mild desquamation and/or dryness	285
415nm LED	open-lab el study		48 J/cm2, receiving two treatments of 20 minutes per week for a period of 4–8 weeks	45	2, 4 and 8 weeks after treatment	mean improvement score was 3.14 at 4 weeks and 2.90 at 8 weeks		286
blue LED, peak wavelength	open-label study	mild to moderat	Over 4 weeks, patients	30	at weeks 5, 8 and 12	An overall effect on inflammatory		287
409–419 nm		e acne	received eight 10- or 20-minute light treatments			counts was observed at week 5, and a statistically significant decrease in inflamed counts was detected at the week 8 assessments, which continued to week 12.