Selective photothermolysis of hair follicles by normal-mode ruby laser treatment.

This study was designed to evaluate the effect of selective photothermolysis on dark pigmented hair follicles treated with a normal-mode ruby laser (694-nm wavelength, pulse duration 0.5 ms, fluence 20 J/cm2, spot size 2 mm). In 15 volunteers, four test areas each were selected. After shaving, the first area was irradiated once, the second twice, the third three times and the fourth served as control area. A punch biopsy was taken from each volunteer immediately after the first laser treatment. Four weeks after the last irradiation, no effect was found in six cases and little effect in another six cases (50-90% regrowth). Hair regrowth of less than 30% was observed in only three cases. Eight weeks after the last session, no effect was found in 11 cases, little effect in 2 cases (10%) and less than 30% regrowth in only 2 cases. Twelve weeks after the last treatment, no difference could be detected between the areas untreated and treated by laser. The laser parameters applied in this study do not result in effective epilation of body hair. In some cases, a delay in growth of several weeks was noticed.