PHOENIX – One cycle of selective transepidermal cooling on the backs of 11 men with healthy, normal skin produced a transient 40% reduction in sebum production by sebaceous glands in a controlled pilot study.
Sebum production fell significantly by 1 and 2 weeks after treatment, compared with production prior to treatment, but by week 4, was not significantly different than at baseline, Dr. H. Ray Jalian and his associates reported at the annual meeting of the American Society for Laser Medicine and Surgery. Sebum production did not change significantly on untreated patches of skin that served as controls.
Dr. H. Ray Jalian
The results give hope that selective cryolysis of sebaceous glands might be a noninvasive treatment for acne vulgaris, which should be explored in additional studies, said Dr. Jalian of the Wellman Center for Photomedicine, Massachusetts General Hospital, Boston.
The study won a top award at the meeting and piqued the interest of attendees. Dr. Jeffrey Dover, immediate past president of the ASLMS, explained the excitement over this small pilot study.
"If you extend that to the future, after they do more studies; more cold for longer [time periods], or maybe more applications may produce prolonged sebaceous gland inactivity," he noted. "And maybe [achieve] permanent sebaceous gland inactivity, which theoretically could be a cure for acne – there could be Accutane-like results with an applicator that’s cold, with no side effects," said Dr. Dover, a dermatologist in Chestnut Hill, Mass. "Now, that would be an advance for dermatology," he said in an interview.
Sebumeter measurements at 2 weeks (the primary outcome measure) showed a 40% reduction in sebum production for two temperature settings, compared with baseline.
The study involved the off-label use of a handheld cooling applicator that has been approved for body sculpting to destroy fat in some body areas. Lipid-rich tissue is susceptible to cold injury, and the researchers hoped to target the lipid content of the sebaceous glands.
Participants were randomized to treatment on select areas of their backs at temperatures of –10° C or –15° C, and they received either a single 20-minute cooling cycle or two 10-minute cooling cycles with rewarming in between. Some skin areas on the scapulas served as control sites, and each subject had two treatment sites and one control site. Sebum measurements and standardized clinical photos were taken just before treatment and on follow-up visits at 3 days (72 hours) and at 1, 2, and 4 weeks.
Among secondary outcomes, a smaller but significant sebum reduction occurred at 1 week, but sebum production did not differ significantly at 72 hours or at 4 weeks, compared with baseline. Transient pain reported during treatment (average on a Visual Analog Scale score of approximately 3 on a 10-point scale) disappeared quickly post treatment and at follow-up visits. "It actually was a very-well-tolerated procedure," Dr. Jalian said.
Transient post-treatment erythema, dysesthesia, and edema also cleared quickly, though one subject had erythema lasting approximately 72 hours, according to blinded evaluators.
"Perhaps the most interesting part of our study was the histology," Dr. Jalian noted. Biopsies from a subset of participants showed histologic evidence of sebaceous gland damage after treatment that persisted at weeks 1 and 2.
There was no clinical or histologic evidence of damage to tissue outside of the treated areas.
"Selective cryolysis of sebaceous glands is achievable through noninvasive cooling," said Dr. Jalian. Future studies may examine whether repeated treatments could maintain the reduction in sebum output beyond 2 weeks, he added.
Previous studies have shown that a 30%-50% reduction in sebum is needed to produce a 50% improvement in acne (Br. J. Dermatol. 2010;163:683-8).
The human pilot study followed preclinical experiments on the ears of mice, sheep, and pigs that showed histologic damage in sebaceous glands after treatment, Dr. Jalian said.
The study was funded by Zeltiq Aesthetics, which makes the handheld cooling device. Dr. Jalian reported no other relevant disclosures.
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