While dermatologists and others are increasingly using lasers and light-based therapies to treat acne, the literature proving efficacy among these therapies is limited by few high-powered trials and lots of small, low-quality studies, according to a review of the medical literature on the use of laser therapy for the treatment of active acne vulgaris.
The need and potential demand for an alternative to medical therapy makes this topic timely, according to the study’s senior author Arielle R. Nagler, M.D., assistant professor in The Ronald O. Perelman Department of Dermatology at NYU Langone Health, New York City.
“We’re at a point in acne where there have been some advances, but we are in need of additional therapeutic options. Lasers are other treatment modalities that we should consider,” Dr. Nagler says. “They provide an alternative modality, especially now patients are generally very interested and excited about lasers.”
Dr. Nagler and colleagues searched PubMed on September 1, 2016, uncovering studies looking at acne treatments with erbium glass, Nd:YAG, pulse dye laser, potassium titanyl phosphate (KTP) laser and laser-based photodynamic therapy for the treatment of acne.
Many of the lasers used to treat acne have longer wavelengths and penetrate deeper into the skin, actually into the dermis. According to Dr. Nagler, many of the laser treatments used for acne are thought to target the sebaceous glands and decrease sebum production. Sebum plays a role in acne pathogenesis.
Additionally, although many of the lasers used in these studies are not commonly used in practice, some — the pulse dye laser, for example — can be used for other indications in addition to acne, she says.
SELECTED LASER TREATMENTS
Many of the lasers studied for the treatment of active acne are infrared spectrum, such as the Erbium laser, and have longer wavelengths.
“Their mechanism of action is thought to be through coagulation and targeting the sebaceous glands” says Dr. Nagler.
The authors found that the erbium laser, which is more commonly used for acne scarring, has shown promising results in several studies for acne treatment. These studies were notable for the long-term benefit of a single erbium treatment, where one treatment could lead to lasting effects.
The 1,064 Nd:YAG also has been studied in some larger, but uncontrolled, studies. In one study, the treatments with the 1,064 Nd:YAG laser were associated with reduced expression of IL-8 and NF-kB, she says.
In addition to infrared lasers targeting sebaceous glands, the authors also found studies using both the 585 nm and the 595 nm pulse dye lasers and the KTP laser for the treatment of acne. The mechanism of action for these lasers in acne is largely unknown, but they are not thought to target the sebaceous gland, she says.
“Unfortunately, many of the studies with [pulse dye laser] for active acne used the 585nm laser, whereas, the 595 nm is more commonly used today” Dr. Nagler says.
The KTP laser, a green light laser, is postulated to treat acne through photo activation of porphyrin and destruction of Propionibacterium acnes, or P. acnes, another factor in acne pathogenesis, according to Dr. Nagler. The review revealed KTP, which isn’t widely used anymore, has been investigated in a few split-face studies in acne, which have largely shown only mild, temporary improvement.
Importantly, the studies included in this review suggest that the lasers that have been studied to treat acne have been well tolerated with the main side effects being pain, redness and some discomfort.
Studies also have looked at lasers and photodynamic therapy, combining light with a typically topically applied photosensitizer, for acne. The lasers studied with photodynamic therapy in acne include the pulse dye laser, KTP and erbium:YAG. These treatments are thought to act through the preferential uptake of the photosensitizer in the sebaceous unit and free radical destruction of P. acnes upon exposure to the laser, she says.
Although photodynamic therapy with blue and red light has been more extensively studied in acne, the studies using lasers with photodynamic therapy, while promising, are extremely limited having been done in a small number of patients, according to Dr. Nagler
“Laser based [photodynamic therapy] for acne is not standard of care, but something that we may want to study more,” she says
All in all, there is no stand-out laser treatment for acne, but several lasers have been studied.
“At this point, there isn’t enough data to point to one modality. There are likely meaningful differences in their efficacy in the treatment of acne, but there aren’t randomized trials powerful enough to elucidate these differences,” Dr. Nagler says. “Nevertheless, the smaller available studies are promising, and we should investigate the use of laser for the treatment of acne more extensively.”
If laser treatment does pan out in high-powered studies, lasers would fill a gap in acne treatment.
“Lasers and other light-based treatments for acne are potentially exciting therapies because many of the medical treatments for acne require daily use and can be associated with side effects. So, many people—especially, young patients--may prefer single, in office, physical treatments for acne,” she says.
Wiznia LE, Stevenson ML, Nagler AR. “Laser treatments of active acne,” Lasers Med Science. Aug. 4, 201: 10.107. DOI:07/s10103-017-2294-7