Pulsed dye laser therapy not effective in treating acne

Unfortunately, there also appears to be no benefit, at least with one type of laser treatment called pulsed dye laser therapy, according to new research from the University of Michigan Health System. The study, which appears in the June 16 issue of the Journal of the American Medical Association, found pulsed dye laser therapy was not effective in treating acne.

Many dermatologists already use lasers to treat various conditions, including wrinkles, scars and acne. However, few randomized, controlled clinical trials have examined the value of lasers for treating acne and none show conclusively whether the treatments actually work.

“Acne affects the vast majority of people at some point and may have a significantly negative impact on their lives. Lasers have the potential to be a safe and convenient treatment option – but only if it’s effective. The only way to know how to advise patients is to objectively study these treatments,” says lead study author Jeffrey Orringer, M.D., clinical assistant professor of dermatology at the U-M Medical School.

In this study, researchers randomly assigned 40 participants with acne to receive treatment to either the left side or right side of their face. The untreated half of the face could then serve as a comparison that would take into account each person’s natural skin changes.

The treatment involved moving a wand-like device across the person’s face to deliver nearly 400 laser pulses. Each treatment lasted about 10 minutes, and most people reported no side effects. The pulses felt like a rubber band snapping and some participants reported slight redness that lasted a few hours. Patients returned for clinical examinations, including counts of the number of acne lesions, every two weeks for 12 weeks. In addition, both sides of the face were photographed at each visit, and a panel of three dermatologists later assessed the overall severity of the acne. These doctors and those conducting the clinical examinations were not aware of which side of each person’s face had been treated.

The researchers compared the differences in subjects’ acne severity from the beginning of the study to the conclusion 12 weeks later. In that time, on average, the side of the face that received treatment showed the same degree of change – for better or worse – as the side that was not treated, indicating that the laser therapy did not impact the course of the disease.

A study published last year in the journal Lancet reported positive results with very similar therapy. That study was published while the UMHS study was ongoing. The Lancet study did not include a split-face design, however, and instead used separate participants who received placebo therapy as a comparison.

“In our study, we saw some patients’ skin getting better, and we saw other patients’ skin worsening. However, the changes were the same for both the treated and untreated sides of the face. It is easy to see how, without the split-face design, some changes could be interpreted as a treatment-related improvement,” says Orringer, director of the Cosmetic Dermatology and Laser Center at UMHS.

Pulsed dye lasers have been used successfully to treat vascular lesions, including such conditions as port wine stains. There is also some evidence that the therapy may improve fine wrinkles and acne scarring by increasing collagen production.

Laser therapy is an attractive option for treating acne because it produces so few side effects and avoids the potential complications of medications. It may also be more convenient for patients than applying daily topical creams. In addition to pulsed dye lasers, other types of laser therapy using different wavelengths of light are being used to treat acne.

Most studies on laser therapy for acne have been small and not rigorously designed, Orringer says. But because the devices are cleared for use and because most don’t generally cause harm to patients, many dermatologists are using lasers in clinical practice based on these early studies and anecdotal reports of success.

“Lasers may prove to effectively treat acne. This paper is not meant as an indictment of all laser therapy for acne,” Orringer says. “But we need rigor in our clinical trials. We need to study these devices thoroughly before recommending them to physicians, who are spending a lot of money to buy the lasers, and more importantly to patients, who may be seeing no significant clinical benefits.”

The study was funded by the Babcock Endowment for Dermatological Research at U-M, ICN Pharmaceuticals Inc., a Dermatology Foundation Clinical Career Development Award in Dermatologic Surgery and the National Institutes of Health. ICN Pharmaceuticals donated the NLite? Lasers used in the study, but the study was designed, performed, analyzed and reported solely by the faculty and staff of the U-M Department of Dermatology.