SAN FRANCISCO – Use of light-based therapy for acne is increasing, despite a lack of proof that it works.
“Light-based therapy has become very popular as there is increasing public demand for nonpharmacologic options,” Dr. Christina Kim said at the meeting.
Dermatologists like light-based therapy for acne for a few reasons. It offers an alternative to isotretinoin for women who are concerned about the drug's teratogenicity. As a nonantibiotic alternative, light-based therapy does not contribute to the emergence of antibiotic resistance. Patient adherence to topical therapies is low, said Dr. Kim, a dermatologist at the University of California, Los Angeles.
“However, the efficacy of light-based therapy has not been proven,” she added. That's mostly because, unlike new medications, the Food and Drug Administration requires medical devices to be proven only safe, not efficacious. she said.
Light-based therapy works, theoretically, because light with a wavelength of 400-700 nm reacts with endogenous porphyrins to create reactive oxygen species that are toxic to Propionibacterium acnes. This effect is enhanced with the photosensitizing agent aminolevulinic acid.
Longer wavelengths with deeper penetration may damage the sebaceous glands and provide a more effective therapy, but the safety of that strategy is unknown. “It's not clear if that's 100% safe – to permanently destroy your sebaceous gland,” she said.
Dr. Kim said she has no pertinent conflicts of interest.