• Home-device safety. This is an area of such great concern that she and her colleagues in the European Society for Laser Dermatology recently published hair-removal home-device safety guidelines (J. Eur. Acad. Dermatol. Venereol. 2012;26: 799-811).
"People just aren’t being trained in the safe use of these devices," she cautioned.
The risks associated with improper use include ocular injury, skin burns, and paradoxical hair growth, as is the case with devices used in physicians’ offices.
The paradoxical hair growth risk in untreated areas close by treated skin is an issue that has been largely beneath dermatologists’ radar prior to the European guidelines. The reported risk with professional devices used by dermatologists is 0.6%-10%. With home devices, who knows?
"It’s a real matter of concern these days. When you lower the fluences, the incidence of paradoxical hair growth may be even higher. There’s nothing in the literature yet, but I’m sure there will be in the next few years," Dr. Haedersdal said.
Patients at increased risk for paradoxical hair regrowth are women with darker skin types, typically with polycystic ovarian syndrome, who are undergoing facial treatment. The mechanism of paradoxical hair regrowth is unknown. Two leading possibilities are light-driven triggering of inflammatory mediators or stimulation of the hair cycle secondary to subtherapeutic thermal injury, she continued.
• Burn scars. A solid body of evidence has accrued regarding the efficacy and safety of both ablative and nonablative fractional lasers to remodel mature burn scars.
Particularly noteworthy was a recent prospective, single-arm, blinded-evaluator study in which a 1,550-nm nonablative fractional erbium laser was employed to treat burn scars in 10 patients. Ninety percent of patients showed improved skin texture and 80% demonstrated improvement in dyschromia, something that hasn’t previously been reported with laser therapy (Lasers Surg. Med. 2012;44:441-6).
The 13 published studies of nonablative fractional laser therapy for burn scars show 26%-50% improvement. That’s slightly less than the 26%-83% improvement reported in the 13 studies of ablative fractional lasers. On the other hand, nonablative fractional laser therapy entails fewer side effects: 1-3 days of erythema and a postinflammatory hyperpigmentation rate of up to 13%, compared with 3-14 days of erythema with ablative fractional laser therapy and a postinflammatory hyperpigmentation rate of up to 92%. As yet, though, there have been no head-to-head comparative studies of the two types of devices.
• Onychomycosis. This is a brand-new area for laser therapy. A recent review noted that, while the Food and Drug Administration has approved four YAG lasers for treatment of onychomycosis, the regulatory standards for device approval don’t require persuasive evidence of efficacy, unlike for drugs (J. Am. Podiatr. Med. Assoc. 2012;102:428-30). Although it’s a promising technology, the authors stated that there are as yet no data showing how laser therapy stacks up against existing standard treatments for onychomycosis in terms of efficacy.
Nevertheless, Dr. Haedersdal noted, attention-getting cure rates were seen in a recent Chinese study involving 154 laser-treated nails in 33 patients. The week-24 complete cure rate, both mycologic and clinical, was 51% after eight weekly treatments and 53% after four weekly treatments (Chin. Med. J. 2012;125:3288-91).
Dr. Haedersdal reported serving on the scientific advisory boards for Galderma, LEO Pharma, and Procter & Gamble.