Pulsed Dye Lasers (PDL)

Pulsed Dye Laser Treatment of Erythema

Pulsed Dye Lasers (PDL) are occasionally used for the treatment of both active acne symptoms and acne scars. Although they can be used for multiple applications, Pulsed Dye Lasers are not usually not first-choice for the treatment of active acne or acne scars.

How Does Pulsed Dye Laser Treatment Work?

Pulsed Dye Laser (PDL) Treatment
Pulsed Dye Laser (PDL) Treatment

Dye Lasers get their name from the fact that they use a specialized liquid dye suspension, instead of a crystal, as the source of the laser beam. Pulsed Dye Lasers (PDLs) are designed to deliver short bursts of light that last only a fraction of a second. Many Pulsed Dye Lasers can be adjusted (tuned) to create lasers of several different wavelengths (colors). For dermatology purposes, Pulsed Dye Lasers that produce laser beams at ~495 nm (green/yellow) are the most common.

The most popular dermatology application for Pulsed Dye Lasers is for the removal of birthmarks and other hyper-pigmented marks on the skin. Low power Pulsed Dye lasers are also used to improve the appearance of wrinkles by stimulating regrowth of the tissue immediately underneath the skin.

Pulsed Dye Lasers can be used for two ablative and non-ablative treatments. Ablative treatments (ablative means to be removed or vaporized at very high temperature) utilize longer laser pulses and/or high light intensity to thermally damage or destroy the target tissue. Certain molecules, like oxyhemoglobin (found in red blood cells), preferentially absorb energy from Pulsed Dye Lasers. This feature makes Pulsed Dye Lasers a viable treatment for spider veins, erythematous acne scars and other skin discolorations caused by damaged or dilated blood vessels.

Ablative laser treatments destroy the target tissue, which is then replaced by new, healthier tissue. Researchers are experimenting with using ablative laser treatment to target and destroy the sebaceous glands, whose hyperactivity can contribute to acne symptoms. However, longer wavelength laser sources, like diode and CO2 lasers are generally preferred over Pulsed Dye Lasers for many dermatology applications.

The more common application of Pulsed Dye Lasers is for non-ablative treatments. These treatments are intended to stimulate tissue growth or to target specific molecules like porphyrins. Although most commonly used to improve skin tone and correct small wrinkles, Pulsed Dye Lasers are also used to improve the appearance of mild acne scars.

Pulsed Dye Lasers and Active Acne

Chart Showing Good Efficacy of PDL Treatment of Active Acne (Jung)
Chart Showing Good Efficacy of PDL Treatment of Active Acne (Jung)

There are a handful of clinical research studies that found Pulsed Dye Lasers may be effective for treating active acne infections. There are also a few studies that found PDLs were not effective treatments for active acne. This disagreement is likely because there are several different kinds of PDLs, and the treatments being researched are not all the same for every study.

Chart Showing Poor Efficacy of PDL for Treatment of Activ Acne (Orringer)
Chart Showing Poor Efficacy of PDL for Treatment of Activ Acne (Orringer)

Pulsed Dye Lasers can be used as part of Photodynamic Therapy (PDT), which is a treatment that targets sebaceous glands and acne-causing P. acnes bacteria. Photodynamic Therapy works better with adjustable PDLs that are capable of producing a laser with a wavelength near 415 nm (ultraviolet), instead of the more common 595 nm (green/yellow). However, PDLs are rarely used for PDT because there are more accessible (and less expensive) light sources available for this treatment.

PDL Acne Treatment Before and After (Harto)
PDL Acne Treatment Before and After
(Harto)

PDLs are also being studied as a way to selectively ablate the sebaceous gland, which then inhibits sebum production and reduces acne symptoms. While the research indicates using PDLs is a a viable approach, there are alternative lasers (eg. Diode Lasers) with longer wavelengths that are better suited for this application.

Pulsed Dye Lasers can also be used to directly kill acne-causing bacteria. The acne-causing Propionibacterium acnes bacterium produces a special molecule called porphyrin. When porphyrin is exposed to high intensity light at a wavelength around 420 nm (ultraviolet/blue) it generates free radical molecules which can kill the bacterium.  This process is called Blue Light Photherapy. Pulsed Dye Lasers are available that can generate high intensity light in this spectrum. However, other high-intensity sources of blue light (eg. LEDs) are substantially less expensive than PDL and are generally used for this type of acne treatment.

Pulsed Dye Lasers and Acne Scars

Treatment of Acne Scars with PDL (Alster)
Treatment of Acne Scars with PDL (Alster)

The most common application of Pulsed Dye Lasers is for the treatment of acne scars. Both ablative and non-ablative PDL treatments are available for treating acne scars. Pulsed Dye Lasers are generally only used for the treatment of mild acne scars. Improvements in acne scars following PDL treatment are usually modest and superficial. The Pulsed Dye Laser platform is not well suited to correct severe acne scarring. This is because most PDL systems do not penetrate deeply enough into the skin tissue to correct significant acne scar damage.

On average, Pulsed Dye Laser treatment of acne and acne scars is reviewed as poor to moderate by patients after treatment. It is likely that PDLs are popular because they are a relatively inexpensive, versatile and common platform and not because they are highly efficacious for acne treatment.

How and Where is Pulsed Dye Laser Treatment Administered?

Candela Vbeam Laser System
Candela Vbeam Laser System

Pulsed Dye Laser treatment is usually administered at a dermatology or cosmetic surgery clinic. PDL systems can also be found at some spas specializing in light and laser therapy. As with almost all laser-based treatments, there is the potential to cause permanent damage and PDL treatment should only be administered by a trained and certified professional.

Pulsed Dye Laser treatments generally cost between $200 and $600 per session. In almost all cases, multiple sessions are required. Research studies on the use of PDL systems for the treatment of active acne for acne found that optimum results required at least four treatments. In addition, PDL-based treatment of active acne usually only provides temporary relief, and acne symptoms eventually return.

Overall, a complete PDL treatment plan for active acne usually starts around a thousand dollars, and goes up from there. PDL treatments are comparable in cost to many other laser treatments, but their mediocre efficacy make them a relatively poor value. The cost and the number of visits required for PDL-based treatment of acne scars varies considerably, depending on the specific application, the amount of damage and the size of the affected region.

Popular Pulsed dye laser (PDL) Systems

C-Beam, Cobra, Cynergy, Navigator, N-Lite, PhotoGenica, Regenlite, Vbeam.

Pulsed Dye Laser Images

References

Laser Treatment of Acne Vulgaris. Jih, et al. 2007.
Investigation of the Mechanism of Action of Nonablative Pulsed Dye Laser Therapy in Photorejuvenation and Inflammatory Acne Vulgaris. Seaton, et al. 2006.
Treatment of Acne Vulgaris With a Pulsed Dye Laser: A Randomized Controlled Trial. Orringer, et al. 2004.
Improvement of Facial Acne Scars by the 585 nm Flashlamp-Pumped Pulsed Dye Laser. Alster, et al. 1996.
Comparison of a 585-nm pulsed dye laser and a 1064-nm Nd:YAG laser for the treatment of acne scars: A randomized split-face clinical study. Lee, et al. 2008.
Dye Lasers @ Wikipedia
Pulsed Dye Laser Patient Reviews @ Realself.com

Pulsed Dye Laser Treatment of Erythema