161 Effect of Intense Pulsed Light on Hair Cycle. Clinical and Histological Aspects.

G Moreno-Arias1, C Castelo-Branco2, J Ferrando1. Depts. of 1Dermatology and 2Gynecology, Hospital Clínic, University of Barcelona, Spain.

The aim of this prospective, randomized, controlled clinical assay was to evaluate the clinical and histological response to intense pulsed light (IPL) in 49 females with hormonal or idiopathic facial hirsutism (chin/sideburns) and dark/coarse hair. Age ranged between 13 and 62 years while skin phototype was II-IV (Fitzpatrick’s scale). The treatment was an intense pulsed light source (EpiLight™, ESC Medical Systems, Israel) with 695- 755 nm, 10×45 nm spot, 3.5-3.8 ms pulse length, triple mode, fluence of 40-43 J/cm2 at 8-week intervals. A total of 4 to 8 sessions were administered. Clinical pictures, trichogram per area unit and terminal hair digitalized photo-count were performed before each treatment session in both control and study areas. Two biopsies were performed to each patient, one at the beginning of the study in the control area, and the second one after any of the treatment sessions in the study area. Conventional optical microscopy, androgenic hormonal profile and a gynecological (CCB) evaluation were performed. We observed a decrease in terminal hair count with an increase in the proportion of vellus-like hair. Delayed hair regrowth and minimal side effects were also evidenced. Trichograms showed a decrease in the anagen/telogen ratio with dystrophic broken hairs. Histological findings disclosed: architectural changes in the follicular unit, perifollicular vacuolization, focal damage to sebaceous gland and ostium dilatation. Intracellular edema, apoptosis, intra and extra-cellular melanin debris, perifollicular inflammatory infiltrate and fibrosis, and neocolagenogenesis were also observed. These results allow us to confirm IPL epilation as a safe and effective treatment method for hirsutism.