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Louise Gagnon is a medical writer and editor based in Oakville, Ontario, Canada.
The use of a fixed combination of 924 nm and 975 nm continuous wave laser energy can treat primary axillary hyperhidrosis, according to a study presented at the 2012 annual meeting of the American Society for Laser Medicine and Surgery.
Kissimmee, Fla. - The use of a fixed combination of 924 nm and 975 nm continuous wave laser energy can treat primary axillary hyperhidrosis, according to a study presented at the 2012 annual meeting of the American Society for Laser Medicine and Surgery.
"The difference is in the selectivity of these wavelengths," explains Mitchell Chasin, M.D., the study's principal investigator and medical director, Reflections Center for Skin and Body, Livingston, N.J.
"The 924 nm wavelength is exquisitely absorbed by fat and spares the dermis. The predominant number of glands are in the superior aspect of the subcutaneous tissue and not in the skin. When you look at where most of the sweat glands are, they are in direct proximity to the fat. We use the 975 nm wavelength in combination because it selects the dermis where water is the target and where the remainder of the sweat glands reside," he says.
"They are not putting the energy where the glands are," he explains. "There is not enough absorption (of energy) by the target. By the time there is enough energy absorbed to damage the sweat glands, you start seeing damage to other tissues as well.
"When we use a combination of 924 nm and 975 nm wavelengths, the histology shows there is clear thermal damage to the apocrine and eccrine sweat glands," Dr. Chasin says.
The study of 22 patients, including 16 women and six men with a mean age of 34 and a range of ages of 17 to 45, excluded patients who had undergone onabotulinumtoxinA injections within the past year, those who had undergone previous axillary surgery, patients with insulin-dependent diabetes, and patients who were pregnant. The study also excluded patients who had axillary hyperhidrosis secondary to another condition like thyroid disease.
All patients in the study reported a grade 4 rating on the Hyperhidrosis Disease Severity Scale (HDSS), meaning underarm sweating was severe and constantly interfered with their daily activities. In terms of transepidermal water loss, the measurement was 15 times the normal range in all subjects in the study.
Investigators performed baseline Vapometer readings and starch iodine sweat tests. Complete anesthesia was achieved using a modified Klein tumescent formula. Investigators divided the axillae into sections and administered laser energy to each section, up to a maximum infrared skin temperature of 39 degrees Celsius. Depending on the size of the sweat area, total energy delivered per side ranged from seven to 11 joules. Cannulas were then used for suction curettage of the region.
Histological examination pre- and postprocedure showed destruction of eccrine and apocrine sweat gland units. In addition, patients took part in follow-up interviews over a nine-month period postprocedure, and some beyond one year. Universally, patients reported a drop in the HDSS scale of at least two levels, meaning sweating was significantly improved and didn't interfere with daily activities. The improvement was described as immediate, and subjects judged their decrease in sweating in excess of 90 percent. Only one patient required touch-up treatment at the three-month mark.
Treatments such as onabotulinumtoxinA (Botox, Allergan) provide some assistance in curbing underarm perspiration, but if the hyperhidrosis is quite severe, patients need to look to other treatment options, Dr. Chasin says.
"Botulinum toxin is better for mild sufferers," he says. "People who have severe type sweating, which would be stage 4 on the HDSS, don't respond as well to botulinum toxin and typically have limited longevity of its effects."
Some patients require more frequent injections of Botox to reduce perspiration, while others require less frequent injections of Botox. "Botulinum toxin initially works, but then it dissipates over time," Dr. Chasin says. "People worry when it will wear off, and they will be embarrassed by the effects of their condition."
Given that it is not thought that sweat glands regenerate, the AxiLase treatment is regarded as permanent, Dr. Chasin explains.
Future studies will evaluate the effectiveness of laser without suction curettage on individuals with grade 2 and grade 3 ratings on the HDSS, Dr. Chasin says. Food and Drug Administration approval for AxiLase is pending. DT
Disclosures: Dr. Chasin reports no relevant financial interests.