• Red light therapy rarely causes adverse events.
• When it does, reactions are minor and may include headaches, ocular impacts and dyspigmentation.

Red light therapy is safe for most dermatologic conditions. But overuse or misuse has been linked to reports of headaches, ocular injuries and other adverse events that can be avoided with some commonsense precautions.

In this Beneath the Surface video interview, Joel M. Gelfand, MD, MSCE, FAAD, the James J. Leyden Professor of Clinical Investigation and professor of dermatology and epidemiology at University of Pennsylvania’s Perelman School of Medicine and Healio Dermatology’s Chief Medical Editor, spoke with David M. Ozog, MD, FAAD, FACMS, chair of the department of dermatology at Michigan State University College of Human Medicine, about the safety of red light therapy.

“There is very little in terms of concern. There have never been cases of death, serious burns or hospitalizations,” Ozog said. “There are very few treatments where you can’t get to some excess and hurt someone. I would put red light therapy in that category.”

Nevertheless, red light therapy is associated with a potential risk for certain adverse events, the most well-known being ocular injuries, according to Ozog.

“We have not seen ocular injuries, but you could do it,” Ozog said. “If you get close enough and create enough energy, particularly if you have anything else in your eye that could possibly absorb that energy, an injury is possible.”

Low-level red light therapy has been approved for macular degeneration; however, the devices used for this indication are not the same as the ones used in dermatology. Ozog recommends that red light therapy users always wear the eye protection that comes with their device.

Although low, the likelihood of experiencing an adverse ocular event increases if you have a darker color eye, according to Ozog. The risk for adverse events with red light therapy, particularly overheating or dyspigmentation, increases for people with skin of color in general.

“If you are getting hot from the light, that means it is too much energy or it is too close,” Ozog said. “You should not feel a heat effect, but people with skin of color tend to warm up a little more quickly.”

Isolated instances of pigmentation changes from red light therapy in skin of color have also been documented, prompting general awareness concerning the best times to use red light therapy in this population, according to Ozog.

Adverse events are also associated with overuse of red light therapy.

“There is a subset of patients who feel that more must be better,” Gelfand said. “But more could actually be worse.”

A common reaction to red light therapy overuse followed by withdrawal is headaches. According to Ozog, this may be due to vasodilatation, but the cause remains unknown.

“Most of us have seen this in our daily lives ... work out a little bit too much and you damage your tissue,” Ozog said. “So, there does appear to be a [limit] and we are still trying to figure that out.”

Editor’s note: Beneath the Surface is a video series in which Joel M. Gelfand, MD, MSCE, FAAD, Healio Dermatology’s Chief Medical Editor, discusses hot topics in the field with leading experts. This four-part edition is focused on red light therapy. Part one can be found here. Part two can be found here.

Joel M. Gelfand, MD, MSCE, FAAD, is the James J. Leyden Professor of Clinical Investigation and professor of dermatology and epidemiology at University of Pennsylvania’s Perelman School of Medicine and Healio Dermatology’s Chief Medical Editor. Gelfand can be reached at dermatology@healio.com.

David M. Ozog, MD, FAAD, FACMS, is chair of the department of dermatology at Michigan State University College of Human Medicine and the C.S. Livingood Endowed Chair of Dermatology and chair of the department of dermatology at Henry Ford Health. Ozog can be reached at dozog1@hfhs.org.