EXPERT ANALYSIS FROM WCD 2015

VANCOUVER (FRONTLINE MEDICAL NEWS) – Six developments – daylight photodynamic therapy, body sculpting, better laser treatments for tattoo removal, marketing of home-use fractionated lasers for skin rejuvenation, novel lasers for vascular malformations, and light-based microphoton microscopy as an alternative to conventional histopathology – will have significant impact upon dermatologic practice, Dr. Christopher B. Zachary predicted in a keynote address at the World Congress of Dermatology.

Savvy patients will increasingly be asking their dermatologists about them, added Dr. Zachary , professor and chair of the department of dermatology at the University of California, Irvine.

Several of these advances fall within cosmetic dermatology, a field he vigorously defended. Showing before-and-after facial photos of a middle-aged woman who appeared 10-15 years younger following skin resurfacing with a fractionated ablative laser, Dr. Zachary asserted, “You can dramatically change people’s lives with this therapy.

“When this lady’s at work, she’s surrounded by younger women who want her job. So, this therapy has social and economic benefits,” he said. “I know that some of you in the audience might think that aesthetics is sort of a Cinderella sister to mainstream dermatology, but it’s important. We’re going to live longer, hopefully, and we want to look good – because in this culture, that’s important.”

* Daylight photodynamic therapy: Developed in Scandinavia as a field therapy for photodamaged skin and precancerous skin conditions, daylight PDT delivers continuous, low-level activation of protoporphyrin IX rather than the faster activation achieved with pulsed dye laser or other artificial light sources.

The big advantage of daylight PDT is that it’s essentially pain free. In contrast, most patients find traditional PDT so unpleasant they are reluctant to return for a second session. Moreover, natural daylight is actually a better light source, in Dr. Zachary’s view, because daylight includes a peak at about 625 nm, which allows for deeper penetration into the skin.

Daylight PDT is quite popular throughout Europe, and it’s sure to catch on here, according to Dr. Zachary, who has published research confirming its safety and efficacy ( Lasers Surg. Med. 2015;47:168-72 ). Because patients receive their daylight therapy at home, it saves time for the patient, physician, and clinic. Plus, physicians avoid the need for expensive equipment, he noted.

Dr. Zachary offered a tip based upon his daylight PDT experience: Because aminolevulinic acid (ALA) is poorly absorbed on the arms and legs, he often pretreats those target areas with a superficial fractional ablative laser to a depth of 20 microns.

“It enhances ALA uptake tremendously,” the dermatologist said.

He also finds daylight PDT to be an excellent therapy for patients with severe, drug-resistant acne. The only difference is they get 4 hours of daylight exposure instead of the 2.5 hours used in field therapy for photodamaged skin. The result is a more robust response, with significant reductions in inflammatory and comedonal acne lesions 2 weeks later. Dr. Zachary typically treats at 2- to 3-week intervals and finds fewer and fewer new lesions appear between consecutive treatments.

“This is, to me, a great therapy. But I’ll tell you, these patients come in after the first 2 weeks and say, ‘I’m never going to have this procedure again, ever.’ Then 2 weeks later they call and ask, ‘When can I have my next treatment session?’ Because they actually get phenomenal results,” according to Dr. Zachary.

* Body sculpting: Cryolipolysis devices to noninvasively reduce substantial quantities of subcutaneous fat in large areas such as love handles are supported by compelling evidence of effectiveness, as documented by MRI and ultrasound studies. The treatment is safe, relatively painless, and the results are predictable, Dr. Zachary noted.

Recently, similar benefits have been shown with bulk heating devices, including 1,060-nm infrared laser systems.

“I will tell you that whether you cool or heat fat for a long period actually doesn’t make much difference,” he explained. “In either case, you’re inducing a delayed-onset panniculitis. There are no acute histologic changes. The panniculitis event occurs at day 14 or so post-treatment, and it causes apoptotic reduction and fat necrosis.”

Other recent useful developments in body sculpting, albeit for treatment of smaller areas, include the Food and Drug Administration’s approval of ATX-101 for reduction of preplatysmal excess submental fat, or the double chin, and the use of botulinum toxin injections for facial contouring. An example of the latter is botulinum toxin injections to reduce the size of large masseter muscles in order to change the facial shape and reduce the common problem of nighttime teeth-grinding, he continued.

* Novel laser therapies for tattoo removal: The new picosecond-pulse lasers are what everyone in laser medicine is talking about. “I think this is definitely the pico epoch,” Dr. Zachary declared.

Twenty years in development, these picosecond lasers produce faster results and more complete clearing of tattoos than obtainable with Q-switched nanosecond lasers. The results are particularly impressive when addressing the traditionally challenging green and blue pigments.

Another noteworthy development in laser tattoo removal has been the use of topical perfluorodecalin to speed tattoo removal using Q-switched lasers. The so-called R20 technique developed by Dr. R. Rox Anderson of Harvard Medical School, Boston, and coworkers ( J. Am. Acad. Dermatol. 2012;66:271-7 ) allows for four treatment passes per session rather than just one pass every 3 months. However, it’s impractically time consuming, because the passes have to be spaced 20 minutes apart.

Physicians at the Laser and Skin Surgery Center of New York have refined the R20 technique by showing that applying perfluorodecalin speeds resolution of the laser-induced immediate whitening reaction. This effectively turns the R20 technique into R0 ( Lasers Surg. Med. 2013;45:76-80 ).

* Home-use fractionated lasers for skin rejuvenation: The skin rejuvenation lasers that dermatologists use in their offices are being miniaturized and made available for home self treatment. Do they work?

“Some do,” according to Dr. Zachary. “If you use them frequently – once or twice a week for an entire year – they’ll probably give you the same benefit as with the traditional in-office treatments. Histologically, they cause a similar tissue injury.”

A host of handheld ultrasound devices for home-use skin rejuvenation are coming soon as well, he added.

* Laser treatment of vascular malformations: There is a growing sense among experts that the 595-nm pulsed dye laser, the traditional workhorse in treating port wine stains, is not the best tool for the job. Targeting additional wavelengths may be a better way to prevent lesion recurrences. The long-pulsed Nd:YAG 1,065-nm laser and 755-nm alexandrite laser appear advantageous in this regard.

* Multiphoton microscopy: At the University of California, Irvine’s Beckman Laser Institute, Dr. Zachary and coworkers are using laser-scanning microscopy to achieve sub-micron-resolution three-dimensional in vivo images of skin lesions. They have found it compares favorably to standard histopathology of processed biopsy specimens for basal cell carcinoma ( JAMA Dermatol. April 24, 2015 [doi:10.1001/jamadermatol.2015.0453 ]).

In other studies, they have compared in vivo multiphoton microscopy to standard histopathology for melanocytic nevi and melanomas. “In some ways, there is better detail than with H&E staining,” according to the dermatologist.

Will this novel in vivo imaging method replace conventional histopathology? Quite possibly, but not for many years to come, Dr. Zachary cautioned.

”I think what’s going to happen is it will take a whole generation of people to understand this. We’ll have to miniaturize these devices, which currently are very large, and put them into clinics so we can look at tens of thousands of lesions before we feel confident in replacing conventional histopathology with noninvasive imaging,” he predicted.

Dr. Zachary reported serving as a consultant to and receiving honoraria and/or equipment loans from Amway, Solta Valeant, and Zeltiq.

bjancin@frontlinemedcom.com

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