Hair Remeval utilzing a Long-pulsed Alexandrite Laser

ABSTRACT

Excess hair growth in unwanted areas may result from heredity, endocrine disease, or drug therapy. Conventional methods of hair removal include shaving, wax epilation and chemical depilatories that frequently cause side effects such as contact dermatitis and that also have temporary effects. Electrolysis is a well-established medical method for permanent destruction of terminal hair follicles. However, this method is tedious and efficacy has been reported to range from 15-to-50% permanent hair loss. The evolution of the laser use for hair removal continues a year after Food and Drug Administration (FDA) approval of the first laser for these applications. The authors have experienced hair removal utilizing a long-pulsed alexandrite laser. This laser system employs the principle of thermokinetic selectivity, a revolutionary concept. The principle of thermokinetic selectivity involves the use of lasers with pulse durations below the thermal relaxation on a the large target such as the hair folllicle (40-100 msec), and significantly longer than the thermal relaxation time of smaller structures of the same chromophore (melanin) in epidermis (3-10 msec). The study was based on 76 patients treated with 20 msec pulse duration laser set to energy densities of 17-21 J/cm2. Treated areas included arms, legs, beard-chin, upper lips and bikini lines. Gross observation showed leaching of hair color, decresed size of the skin pores, easily broken hair shafts, and elimination of hair. Therefore, it can be assumed that the majority of hair follicles were destroyed by this procedure, Side effects included intermediary risk of hyperpigmentation and blister. Over 80% of treated patients were satisfied with the results. As the process of research and clinical application continues, we need the long-term results of this laser system to ensure its efficacy.