Comparative study on a single treatment response to long pulse Nd:YAG lasers and intense pulse light therapy for hair removal on skin type IV to VI--is longer wavelengths lasers preferred over shorter wavelengths lights for assisted hair removal

Abstract

Objective: To investigate the safety and effectiveness of a long pulsed Nd:YAG (1064nm) laser compared to a shorter wavelength intense pulse light system for assisted hair removal in volunteers with skin type 1V, V and VI.

Methods: Eleven patients of Fitzpatrick skin type IV-VI were recruited into the study. The area treated included the face (upper lips, chin and jaw area), axillae and legs. One half of the body was treated with the long pulse Nd:YAG laser and the other half was treated with the IPL system randomly under topical anesthesia. Degree of pain experienced during treatment, the treatment outcome and any complications were observed. Patients were reviewed at 2 weeks and 6 weeks post-treatment.

Results: Volunteers generally described pain from the IPL system as "prolonged burning sensation" but tolerable. Pain from Nd:YAG laser treatment was described as "pinprick" and more intense but tolerable. "Slowing of hair growth"was reported with IPL and Nd:YAG, but with a greater effect from Nd:YAG. Sixty-four percent and 73%(8/11) noticed hair reduction <20% after 6 weeks on IPL and Nd:YAG treated side respectively (ns). Post-inflammatory pigmentation occurred in some volunteers on the IPL treated sides whereas this was not seen on any Nd:YAG treated side, and three of these patients experienced blistering, followed by post-inflammatory pigmentation.

Conclusion: In our experience the long pulse width 1064 nm Nd:YAG laser, which can penetrate 5-7 mm into the dermis depths to reach the whole length of the hair follicle, would be expected to produce sufficient follicular injury with less epidermal damage in patients with darker skin type compared to shorter wavelength laser and light system.