LS5 CRITICAL REVIEW OF HAIR REMOVAL SYSTEMS

Wimmershoff M., Landthaler M., Stolz W., Hohenleutner U., Department of Dermatology, University of Regensburg, Germany

Unwanted hair is a widespread cosmetic problem. Shaving, epilation and chemical depilations are temporary methods of hair removal which are tedious, only partially effective and frequently cause side effects. Recently, several laser systems have been developed for epilation by selective photothermolysis of the hair follicle. These include the long-pulsed ruby laser, long-pulsed alexandrite laser, Nd:YAG laser and the diode laser. The most important difficulty in treating unwanted hair is the fact that hair growth is a cyclical, multifactorial process that is poorly understood. Anagen and telogen vary greatly in different body areas. It is important whether hairs are in anagen or telogen at the time of hair removal because only anagen hairs are especially sensitive to the laser light. Additionally, it is unknown which parts of the follicle have to be destroyed for long-time or permanent epilation. The most likely target sites for inactivation of hair follicles are the bulge (location of the stem cells) and/or the papilla. Long-pulsed ruby lasers operate at a wavelenght of 694 nm which is well absorbed in melanin and less absorbed on other chromophores of the skin. Hair follicles are injured as a result of selective energy absorption by melanin in the bulge area, the papilla and the hair. Until now, several studies have investigated the efficacy of the ruby laser for hair removal. 35-80% regrowth has been reported after multiple treatments with different pulse lengths and spot sizes. We give an overview over recently investigated studies with the long-pulsed ruby laser and our study with a 5-msec long-pulsed ruby laser and the results six weeks and six months after laser irradiation.