Reference: Jagdeo J, Austin E, Mamalis A, Wong C, Ho D, Siegel DM. Light-emitting diodes in dermatology: a systematic review of randomized controlled trials. Lasers Surg Med. 2018;50(6):613–628. doi:10.1002/lsm.22791
Rationale: PubMed-indexed articles on medical uses of LEDs have more than doubled each year since 2010, providing growing evidence of efficacy and safety of therapeutic uses of non-ionizing LED light.
Objective: This systematic review critically analyzed published evidence of safety and efficacy of LEDs used in dermatology and provided evidence-based recommendations for this use.
Methods: Two authors and a research librarian searched the PubMed, Cochrane, EMBASE, and Web of Science databases through 2016 to identify and analyze any RCT that compared at least 1 LED therapeutic arm with any other topical treatment of patients with skin wounds or conditions. Preclinical, non-clinical, and ultraviolet light studies reviewed elsewhere were excluded. Results were tabulated separately for US Food & Drug Administration (FDA)-cleared and for non-FDA-cleared indications. Resulting evidence was graded according to the Oxford Centre for Evidence-based Medicine—Levels of Evidence6 and then used to support related recommendations, which were graded according to statistical consistency (P < .05) of effects supporting dermatologic use of LEDs. Grade A was defined as consistent support by a systematic review of RCTs or high-quality RCT; Grade B was consistent low-quality RCT and/or cohort study and/or case-control systematic review support; Grade C was consistent support from case series and extrapolations from cohort and/or low-quality RCTs; and Grade D was troubling, inconclusive, or inconsistent support from case reports, expert opinion, or bench studies.
Results: Of the 3844 articles screened for inclusion, 31 qualified for inclusion as RCT evidence exploring the effects of LEDs on skin. There were no Grade A recommendations, largely due to limited capacity to conduct double-blind studies of colored light-based interventions, small sample sizes, and variations in stimulation parameters, including distance from source, power density, orientation, and fluence. Grade B recommendations were supported by (1) eight RCTs on 456 patients exposed to red (8–100 mW/cm2) or blue (6–40 mW/cm2) LED for 20 minutes twice weekly to reduce inflammation or counts of acne vulgaris lesions; (2) three RCTs on 147 patients exposed to near infrared (830 nm at 55 mW/cm2 for 10 minutes 4 times over 10 days) to reduce healing time and scarring of herpes simplex and zoster lesions; or (3) five RCTs on 99 patients receiving 2 minutes of daily exposure to yellow (5 mW/cm2) or 20 minutes of daily exposure to near infrared (about 50 mW/cm2) LED to reduce acute wound erythema or healing time. Of indications with Grade B recommendations, only acne vulgaris and herpes simplex and zoster were FDA-cleared. The FDA-cleared skin rejuvenation received a Grade C recommendation for daily treatment with near infrared (55 mW) or red light (55 mW/cm2) combined or alone for up to 20 minutes per day for 8 to 10 weeks to improve skin wrinkles (6 RCTs of 328 patients with 42 withdrawn). Non-FDA-cleared daily treatment of psoriasis with blue light (50 mW/cm2) received a Grade C recommendation based on 3 RCTs (114 patients) for reducing inflammatory aspects of psoriasis. Indications receiving Grade D recommendations not cleared by the FDA were chronic wound healing (2 RCTs on 97 patients), oral mucositis(1 RCT on 80 patients), radiation dermatitis (1 RCT on 33 patients), or cellulite reduction (1 RCT on 9 patients).
Authors’ conclusions: Based on published evidence, acne vulgaris, herpes simplex and zoster (shingles), and acute wound healing have shown improved outcomes in response to LED therapy sufficient to support Grade B recommendations. While other skin conditions have less supporting evidence, rare adverse events, affordability, and encouraging clinical results suggest the merit of further clinical research.