Red Light Therapy for Burns: Scientific Evidence

When researchers added red light to standard dressing care, a 2023 clinical trial tested healing of second-degree burns on the lower legs in patients who rely on steroid medicine. 62 patients were placed into a control group of 25 and a treatment group of 37 according to treatment order and their own preference rather than by randomization, with both groups treated using a 1% silver-based antibacterial cream. The treatment group also receiving 630 to 650 nm red light at 4.5 J/cm² for 20 minutes before dressing, over 21 days. The treated group showed a higher wound healing rate, less discharge from the wound, and more relief at the wound edges than the control group. The study concluded that red light at this range could reduce discharge, ease the reaction at the wound edges and the pain, and promote healing.

Among 40 children with deep burn ulcers who were candidates for skin graft surgery, a 2022 clinical trial compared photobiomodulation (PBM) against the graft. 39 children completed the study, with ulcers averaging about 61 cm² in the PBM group and 64 cm² in the graft group at the start. The PBM group received 650 nm red light at 150 mW over a spot of 0.6 cm², applied for 10 seconds per point to deliver 1.5 J, every other day until the wounds closed. All wounds in the PBM group closed within 10 to 12 sessions. The trial found a significant difference in burn area at 6 months in favor of PBM, and concluded that it was an effective alternative to grafting that lowered the rate of scarring.

Comparing aerobic exercise alone against aerobic exercise preceded by low-level laser therapy (LLLT), a 2022 randomized controlled trial examined fitness in people whose burns had already healed. 60 adults aged 25 to 40 with healed second-degree burns covering 20 to 40% of the body were split into 2 equal groups, with the treated group receiving 808 nm near-infrared light at 800 mW for 8 minutes before each exercise session, 3 times per week for 84 days, and both groups following the same routine physical treatment program. Both groups improved in the most oxygen the body could use during exercise and in how long they could keep going, but the gains were significantly larger in the laser group. Adding laser therapy before exercise appeared to help fitness recovery in people who had been burned. The burns in this trial had already healed, so what was measured was fitness rather than wound healing.

18 patients with recent second-degree burns were treated with fluorescent light energy (FLE) in a 2021 observational study. Treatment used light in the visible range between 400 and 700 nm, with the active band between 440 and 460 nm, at 55 to 129 mW/cm², given in sessions of 5 and 9 minutes twice per week over 14 to 21 days, and laboratory tests on skin samples ran alongside the patient cases. Healing was reported in all 18 patients. No harmful effects and no infections were reported. According to the study, these results are encouraging and point to the need for randomized controlled trials to establish whether FLE works.

A 2019 clinical trial tested low-level laser therapy (LLLT) followed by a graft of the patients' own cultured skin cells for full-thickness burn ulcers in people with diabetes. 10 diabetic patients with full-thickness burn ulcers, all of whom were candidates for skin graft surgery, received red light at 650 nm and 150 mW, delivering 1 J/cm² to the ulcer bed, and near-infrared light at 808 nm and 200 mW delivering 6 J/cm² to the edges, every other day for 10 sessions across 3 to 4 weeks. In contrast, their own skin cells were grown in the laboratory. Wounds measured 16.28 cm² on average before treatment, and all of them closed completely within 10 to 12 weeks. The study concluded that the method can be used for large wounds, particularly in patients with complications such as diabetes. Every patient received both the light and the cell graft, so the effect of light on its own cannot be separated.

Each patient's burned limb was treated while the matching limb on the other side received a placebo, in a 2018 observational study of LED therapy. 5 patients with skin burns received 658 nm red light at 40 mW, delivering 7 J/cm² every other day, with those who had burns on both sides serving as their own comparison, and small skin samples taken and the healing photographed along the way. The treated limbs showed more new skin covering the wound, more growth of the cells that rebuild skin, and more collagen than the placebo limbs, along with less pain and itching. The study found faster clinical improvement on the limbs that received light.

Researchers in China tested systemic red light therapy on wound repair in burned patients, in a 2010 randomized controlled trial. 138 patients were randomly split into a treatment group of 69 and a control group of 69, with the control group receiving routine care and the treatment group also given whole-body red light for 30 minutes once a day until the wounds healed, and assessments made on days 7, 10, 14, and 21 after the burn and again on the day of healing. Deep wounds healed in an average of 19.86 days in the treatment group against 21.02 days in the control group, a statistically significant difference. Pain during dressing changes on days 10 and 14 was also lower in the treatment group. The trial found the approach effective for healing and for pain relief, and described it as safe for these patients.

22 of 67 patients with deep burns reaching the lower layers of the skin were treated without surgery in a 2002 observational study in Belgium. These 22 had been judged to have very limited potential to heal on their own, and 4 of the 6 surgeons involved would have recommended an operation. Still, they instead received polarised light therapy spanning 400 to 2000 nm at 40 mW/cm² and 2.4 J/cm², given for 10 minutes per session until the wounds closed. A panel of 4 burn surgeons judged that healing time was significantly shorter with polarised light, with almost no raised, thickened scarring and good appearance and function at long-term follow-up. No extension of the hospital stay was needed, so polarised light therapy may be a way to avoid surgery in deep burns.