KISSIMMEE, FLA. (FRONTLINE MEDICAL NEWS) – A noninvasive microwave system reduced light and dark axillary hair by approximately 70%, with durable results 1 year after treatment, according to data from a prospective multicenter study of 44 patients.
The device is Food and Drug Administration–approved for thermal treatment of axillary sweat glands, and has been used for about 35,000 such procedures, Dr. Jeremy Brauer said at the annual meeting of the American Society for Laser Medicine and Surgery.
The system targets microwave energy at the interface between the dermis and the hypodermis, “and we hypothesized that heat at this level in the skin may also have an important effect on the hair bulb,” he said.
Hair reduction is the third most common cosmetic procedure that U.S. dermatologists perform, said Dr. Brauer, a dermatologist with the Laser & Skin Surgery Center of New York. Laser is the primary modality, but is not always effective and can cause serious tissue damage if melanin concentrations in the hair and skin are too similar, he said.
For the study, Dr. Bauer and his associates used the microwave device to treat the axillae of 44 patients during either one or two treatment sessions. Average age of the patients was 33 years (range, 18-61 years), 80% were female, and 62% had dark axillary hair. Most had Fitzpatrick skin type II (33%), III (27%), or I (23%), but about 18% had type IV or V. During follow-up visits at 3, 6, 9, and 12 months, three blinded assessors counted hairs within a 2 cm x 2 cm area in the center of each axilla, and also qualitatively compared follow-up and baseline photos.
The blinded assessors correctly chose the baseline photos for all the photographic series, Dr. Brauer said. At 12 months, mean hair reduction was 75% for all patients, 72% for light-haired patients, and 76% for dark-haired patients, he reported. Ranges of response within these subgroups were relatively narrow, but patients who were treated at higher energy levels (settings of 3 or 4) achieved significantly more hair reduction (P < .0001) at 12 months than did patients who were treated at a setting of 1, he said. He recommended that future studies examine dose response and optimal number of treatment sessions.
Dr. Brauer reported consulting fees from Miramar, maker of the device.
