Laser hair removal affects sebaceous glands and sebum excretion: a pilot study

Photothermal therapy using gold nanoparticles and a long-pulsed 755-nm alexandrite laser to treat facial photoaging in Asian skin: A prospective clinical trial

BACKGROUND AND OBJECTIVES

Transdermally delivered gold nanoparticles (AuNPs) irradiated with near-infrared laser energy can create a photothermal effect within the sebaceous glands (SGs). Photothermal therapy (PTT) can be used clinically to reverse photoaging in SG-rich areas of the skin. Improvements in wrinkles and enlarged pores in Asian skin were assessed following AuNP-mediated PTT with a long-pulsed 755-nm alexandrite laser.

STUDY DESIGN/MATERIALS AND METHODS

A single-arm, prospective trial was designed. Twenty Korean patients underwent three gold PTT interventions performed 4 weeks apart at laser hair-removal settings without cooling. At Week 20, changes in the wrinkle index (WI) and pore index (PI), size, and count were calculated using three-dimensional camera analyses. Overall improvements in wrinkles and pores (0-4 scale) were assessed by blinded investigators using standardized photographic comparisons. The subjects scored their satisfaction (0-10 scale) and treatment discomfort (0-10 scale). Safety data were also collected.

RESULTS

There were significant reductions in the WI (8.3%, p < 0.01), pore size (23.1%, p = 0.035), and PI (19.9%, p = 0.034) in the periorbital areas at week 20 compared with baseline. The mean reductions in the size (22.5%, p = 0.027), count (16.5%, p = 0.048), and index (22.4%, p = 0.023) of the cheek pores were also significant. Investigators reported average scores of 3.2 ± 0.6 for improved wrinkle appearance, and 3.1 ± 0.7 for improvement in visible pores. Participants were moderately satisfied with the overall results (7.6 ± 1.8). Subjects felt moderate discomfort during treatment (4.7 ± 2.6). No serious or persistent adverse events occurred.

CONCLUSIONS

AuNP-mediated PTT showed noticeable efficacy and tolerability in treating wrinkles and pores in Asian skin over a 12 week-follow-up. Further studies with a longer follow-up are needed to confirm the reduction in SG activity at the parameters used.

Effects of a long-pulsed 800-nm diode laser on axillary hyperhidrosis: a randomized controlled half-side comparison study

BACKGROUND

Generally, axillary hyperhidrosis (AH) is treated with antiperspirant agents, botulinum toxin, or local surgery. The effect of laser treatment on sweat secretion in patients with AH has not been investigated.

OBJECTIVE

To evaluate the effect of diode laser epilation on the sweat rate of patients with AH.

MATERIALS AND METHODS

We performed a randomized half-side controlled trial. Twenty-one patients were treated with 5 cycles of an 800-nm diode laser. Sweat rates were documented using gravimetry and a visual analogue scale. Histologic examination was performed in all patients before and after treatment.

RESULTS

A significant reduction in sweat rate was observed on the laser-treated (median 89 mg/min, range 42-208 mg/min vs 48 mg/min, range 17-119 mg/min; p < .001) and the untreated contralateral (median 78 mg/min, range 25-220 mg/min vs median 65 mg/min, range 24-399 mg/min; p = .04) sides, although no significant difference was found between the treated and untreated sides (p = .10).

CONCLUSION

Although we observed a significant decrease in sweat rate on laser-treated sites, laser epilation was not able to reduce the sweat rate significantly more than on the untreated contralateral side. These results probably indicate a placebo effect rather than a direct therapeutic effect of laser epilation.

Uncommonly reported side effects of hair removal by long pulsed-alexandrite laser

OBJECTIVE

To provide retrospective clinical review of some uncommonly reported side effects of long-pulsed alexandrite laser treatment for hair removal.

MATERIAL AND METHODS

Two hundred and fifty female patients suffering from hirsutism of the face were subjected to treatment by long pulse alexandrite laser for a maximum of 15 sessions per patient at 5- to 7-week intervals.

RESULTS

Apart from the commonly reported side effects of pigmentary changes, occasional blistering and rare scarring, other untoward effects have been observed. These include - among others - de-novo growth of hair outside the area treated by laser, potentiation of co-existing vellus hair in the treatment area, induction or aggravation of acne, rosacea-like rash, premature grayness of hair, tunneling of hair under the skin, prolonged diffuse redness and edema of the face, focal hypopigmentation of the lip, angular cheilitis, allergic reaction to the cooling gas, and inflammatory and pigmentary changes of pre-existing nevi.

CONCLUSION

Although the efficacy of long-pulsed alexandrite laser seems unmistakable, the short- and long-term untoward effects of such treatment have yet to be carefully delineated and the underlying mechanisms are yet to be adequately clarified.

Optical treatments for acne

Light-based treatments for acne are becoming increasingly commonplace in dermatology. This article reviews various light approaches in acne therapy. Methods are discussed from an anatomical and a functional perspective. The emphasis is on the practicality of treatment as well as the pros and cons of various devices. Also, a review of the recent literature is presented. The article is intended to give the reader a panoramic view of this still-young and developing area. Most likely, light-based acne treatment will receive more popularity as dermatologists learn how to integrate this type of therapy within the context of more established drug agents.

Low-intensity indocyanine-green laser phototherapy of acne vulgaris: pilot study

Near infrared (NIR) diode laser low-intensity (soft) phototherapy with the topical application of indocyanine green (ICG) has been suggested for treatment of acne vulgaris. Twelve volunteers with acne lesions on their faces and/or backs were enrolled in the experiment. Skin areas of the subjects that were 4 x 5 cm2 were stained with ICG solution for 5 min before laser irradiation (803 nm) at a power density up to 50 mW/cm2 for 5 to 10 min. For 75% of the subjects, a single treatment was provided and for the other 25%, eight sequential treatments over a period of a month were carried out. Observations a month after the completion of the treatment showed that only the multiple treatments with a combination of ICG and NIR irradiation reduced inflammation and improved the state of the skin for a month without any side effects. A month after treatment, the improvement was about 80% for the group receiving multiple treatments. Single treatments did not have a prolonged effect.

Selective photothermolysis of the sebaceous glands for acne treatment

BACKGROUND AND OBJECTIVES

The purpose of this study is to evaluate the efficacy of a long pulse diode laser (Cynosure, Inc.) to target and destroy enlarged sebaceous glands that are preloaded with Indocyanine green (ICG) chromophore.

STUDY DESIGN/MATERIALS AND METHODS

This study was designed in three phases. First, preliminary studies were performed to determine the ability of ICG to penetrate into enlarged sebaceous glands. Once penetration of the sebaceous gland was confirmed, the second phase was to determine the necessary parameters for the diode laser to effectively target the ICG loaded glands. This was done using laser-tissue interaction analysis. The final phase was done with patients that had active acne on their back to determine if selective destruction of the sebaceous glands could be achieved and also to assess the safety and efficacy of this novel treatment for acne.

RESULTS

Fluorescence microscopy of biopsy samples show evidence of ICG penetration into the sebaceous glands. Histological examination of biopsy samples from the treated areas finds selective necrosis of the sebaceous glands. Preliminary clinical results demonstrate a decrease in acne noted in the treatment area at 3, 6, and 10 months follow-up.

CONCLUSIONS

ICG and diode laser treatment is a new approach for the treatment of acne based on experimentally observed selective photothermolysis of the sebaceous glands.

Hair removal with the long pulsed Nd:YAG laser: a prospective study with one year follow-up

BACKGROUND AND OBJECTIVE

The aim was to investigate the efficacy, side effects, and the long-term results of a long pulsed Nd:YAG-Laser for hair removal in different hair colors and skin types.

STUDY DESIGN/MATERIALS AND METHODS

We performed a prospective clinical study with 29 volunteers. Treatment was performed on the lower leg with a long pulsed Nd:YAG-Laser. Five test areas were treated 1-5 times in monthly intervals; one served as control. Follow-up investigations were performed at each session, and 3, 6, and 12 months after the last therapy. No depilatory treatment except shaving was allowed during the time of follow-up. Percentual hair loss, short- and long-term side effects, and pain during the treatment were evaluated.

RESULTS

After one month, a hair loss of greater than 50% was found in 44.9% of the areas treated once. With up to five treatments, this percentage increased up to 71.5%. One year after therapy, a greater than 50% hair reduction was still present in 40% of the five-treatment-areas and in 0% of the areas treated only once. There were no permanent side effects despite one small scar after a folliculitis.

CONCLUSIONS

The long pulsed Nd:YAG is suitable to remove hair for more than 12 months effectively, although 4-5 sessions are necessary for these results. Blond hair can also be removed, although much less effective. No lasting side effects could be seen. Darker skin types or tanned skin can also be treated without side effects. A cooling may be advisable due to the pain reported by the volunteers.

Laser hair removal: guidelines for management

Laser-assisted hair removal is the most efficient method of long-term hair removal currently available. Several hair removal systems have been shown to be effective in this setting: ruby laser (694nm), alexandrite laser (755nm), diode laser (800nm), intense pulsed light source (590 to 1200nm) and the neodymium:yttrium-aluminium-garnet (Nd:YAG) laser (1064nm), with or without the application of carbon suspension. The parameters used with each laser system vary considerably. All these lasers work on the principle of selective photothermolysis, with the melanin in the hair follicles as the chromophobe. Regardless of the type of laser used multiple treatments are necessary to achieve satisfactory results. Hair clearance, after repeated treatments, of 30 to 50% is generally reported 6 months after the last treatment. Patients with dark colored skin (Fitzpatrick IV and V) can be treated effectively with comparable morbidity to those with lighter colored skin. Although there is no obvious advantage of one laser system over another in terms of treatment outcome (except the Nd:YAG laser, which is found to be less efficacious, but more suited to patients with darker colored skin), laser parameters may be important when choosing the ideal laser for a patient. Adverse effects reported after laser-assisted hair removal include erythema and perifollicular edema, which are common, and crusting and vesiculation of treatment site, hypopigmentation and hyperpigmentation (depending on skin color and other factors). Most complications are generally temporary. The occurrence of hypopigmentation after laser irradiation is thought to be related to the suppression of melanogenesis in the epidermis (which is reversible), rather than the destruction of melanocytes. Methods to reduce the incidence of adverse effects include lightening of the skin and sun avoidance prior to laser treatment, cooling of the skin during treatment, and sun avoidance and protection after treatment. Proper patient selection and tailoring of the fluence used to the patient's skin type remain the most important factors in efficacious and well tolerated laser treatment. While it is generally believed that hair follicles are more responsive to treatment while they are in the growing (anagen) phase, conflicting results have also been reported. There is also no consensus on the most favorable treatment sites.

Epilation with a long-pulse 1064 nm Nd:YAG laser in facial hirsutism

BACKGROUND

Facial hirsutism and hypertrichosis are common problems and a methods are available to clinicians for the unwanted hair in a large number of patients. Several depilatory laser systems are now available and one of these modalities is the long-pulse Nd:YAG laser.

OBJECTIVE

To evaluate the efficacy of the long-pulse Nd:YAG laser in removing unwanted facial hair.

METHOD

In all, 29 patients completed their treatment course with a long-pulse (4 ms) Nd:YAG (1064 nm line) with fluences between 56 J/cm(2) and 70 J/cm(2). The average reduction in hair density was assessed using hair count on digital photographs at removal 3, 6 and 9 months postoperatively. The hair-free interval was variety of also evaluated.

RESULTS

The average reduction of in the hair count (the same diameter as the baseline for the criterion) was 43% at 3 months, 36% at 6 months, and 46% at 9 months. The hair-free interval with laser was two- to sixfold longer than with self-applied methods. No significant complications were observed in the range of skin types treated, even in the darker skin types.

CONCLUSION

The long-pulse Nd:YAG laser is an effective and safe method for long lasting hair removal in all skin types. The delay in hair regrowth most likely explains patient satisfaction.