March 22, 2012 (San Diego, California) — Ultrasound treatment of axillary sweat glands might offer a nonsurgical option for patients with hyperhidrosis, according to 2 pilot studies presented here at the American Academy of Dermatology 70th Annual Meeting.
"We're hypothesizing that it's permanent; we're destroying the glands," said Mark Nestor, MD, PhD, from the University of Miami Miller School of Medicine in Florida, who received a grant for the study from Ulthera, the company that makes the ultrasound device.
The treatment, known as microfocused ultrasound, is currently approved by the US Food and Drug Administration for the cosmetic indication of "noninvasive lift," he said.
"We hypothesized it could target sweat glands at 2 to 5 mm without surface effects."
The first pilot study enrolled 14 patients, 18 to 75 years of age, with an average baseline gravimetric sweat production of 166 mg at 5 minutes, he said.
For most patients, lidocaine and epinephrine (6 to 8 mL) was injected bilaterally and followed with ultrasound treatment on one side; a sham procedure was used on the other side. To test the effect of different anesthetic approaches, a subset of patients had lidocaine-only anesthesia on one side or no anesthesia.
"We wanted to know if injecting fluid would impede the ability of the device to heat the glands," he said.
Using a plastic grid, the investigators divided the treatment area into 12 squares of about 3 to 4 inches. Two separate transducers — one penetrating to 3.0 mm (7 MHz) and the other to 4.5 mm (4 MHz) — were passed over the area twice, making approximately 120 lines with each pass.
"It's not very easy to pinpoint exactly where the sweat glands are, so the larger the area, the better," Dr. Nestor said. Treatment of each axilla took about 20 minutes.
Patients received 2 treatments 28 days apart. Sweat production was measured gravimetrically 7, 14, and 30 days after the first treatment, and 7, 14, 30, 60, and 90 days after the second treatment.
Overall, there was about an 80% reduction in sweat from baseline. Gravimetric testing showed that 7, 14, and 30 days after the first treatment, there was a 78.3%, 53.9%, and 66.3% reduction in sweat, respectively. Similarly, at 7, 14, 30, and 60 days after the second treatment, there was a was 77.3%, 73.7%, 68.6%, and 79.5% reduction in sweat, respectively, reported Dr. Nestor.
A second pilot study with 20 patients is currently ongoing. It shows about a 60% reduction in sweat production 30 days after the first treatment.
There was no difference in anesthesia between the 2 groups, but the lidocaine plus epinephrine group had the best pain control, he said.
"I have always found that lidocaine with epinephrine is a better anesthetic, without question. It closes the blood vessels and holds the anesthetic in," Dr. Nestor explained. "Without any anesthesia, [treatment-related pain] is probably about a 7 to 8 on the VAS scale. It dropped down dramatically with anesthesia, and patients were extremely comfortable."
In the first study, 35% of patients had mild transient bruising, as did 15% in the second study; this was likely from the anesthesia injection. "We think that as we get better, the anesthesia gets easier and there's less bruising," he noted. Similarly, about 20% reported transient paresthesia, also likely from the anesthetic, and some reported tenderness and soreness.
An alternative treatment for hyperhidrosis is interesting, said Maria Hordinsky, MD, professor and chair of the Department of Dermatology at the University of Minnesota Medical School in Minneapolis, who was part of the abstract selection committee and chaired the session in which this study was presented.
"What grabbed me was the potential to use this in other body regions," said Dr. Hordinsky.
Currently, botulinum toxin is the next alternative after patients have failed topical treatments, but this can involve 30 to 40 injections for roughly a 6-month effect, she told Medscape Medical News.
Sympathectomy, although invasive, is effective for palmar hyperhidrosis but not useful for more diffuse sweating, she said. "This is a device that you could potentially use in these kinds of individuals."
It's too early to determine the duration of the ultrasound results, but early efficacy may not be as good as botulinum toxin. These numbers are still fairly high," Dr. Hordinsky noted.
Dr. Nestor said that more work needs to be done to assess this technique on other body parts, specifically the hands for palmar hyperhidrosis.
"There's much more leeway under the arms. Under the [axillary] sweat glands, there's fat before we get to muscle, and then the muscle guards the nerves. This is not the case in the hands, where we have all the tendons and not a lot of fat," he said.
Dr. Nestor reports receiving a grant for the study from Ulthera, the company that manufactures the ultrasound device. Dr. Hordinsky reports receiving investigator grants from Astellas Pharma US, Allergan, Johnson & Johnson Consumer Products, Lexington International, Medicis Pharmaceutical, and Novartis Pharmaceuticals.
American Academy of Dermatology (AAD) 70th Annual Meeting: Late-breaking abstract. Presented March 16, 2012.
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Cite this: Ultrasound for Axillary Hyperhidrosis Shows Promise - Medscape - Mar 22, 2012.