Laser-assisted hair removal for darker skin types

Before the advent of longer wavelengths, longer pulse durations and more efficient cooling devices, laser-assisted hair removal was best suited for phototypes I-III with dark terminal hairs. Now, laser-assisted hair removal can be performed safely and efficaciously on darker skin types. The long-pulsed diode and Nd:YAG-wavelength-based laser systems are best suited to safely and effectively treat patients with darker skin types. By using conservative fluences, longer pulse durations and multiple treatments, safe and effective laser-assisted hair removal is possible for darker skin types. Patients with darker skin who suffer from hirsutism, hypertrichosis, and pseudofolliculitis barbae can finally be treated safely and effectively.     

Laser resurfacing today and the ‘cook book’ approach: a recipe for disaster?

Background Laser ablative skin resurfacing achieves skin rejuvenation by precise ablation of photoaged skin and subsequent re‐epithelialisation and dermal remodelling. Carbon dioxide (CO₂) and Erbium:YAG (Er:YAG) lasers are the established choice. A wide range and many sets of parameters have been proposed as the gold standard for each system but results have varied. Aims To show that this single system ‘cook book’ approach must be rejected in favour of a more comprehensive approach. Subjects and methods The author has experience of ablative skin resurfacing in over 1200 patients and has used both systems. A more flexible approach, using a combined wavelength system, is presented. It comprises precise ablation of the epidermal with the Er: YAG (to create an epidermal window), followed instantaneously with subablative heating of the exposed dermis with the CO₂ laser. Results Since adopting the dual wavelength/dual modality approach, more than 600 patients have been treated, with excellent results and a very high patient satisfaction index, currently around 90%, obtained from the sum of the very satisfied and satisfied patients using a five‐grade scale. Possible resurfacing‐related complications have included prolonged erythema, hyper or hypopigmentation, scarring and viral infections, which were more common with single system resurfacing. The author's complication rate remains under 1%, without any prophylactic use of antiviral agents. Conclusions The cook book approach, whereby a particular set of fixed laser resurfacing parameters for a specific single laser system are adopted and rigidly applied in all patients, will not achieve the best treatment effects and may even produce a bad result and dissatisfied patients. The dual modality approach allows a combination of the favourable elements of each of the two wavelengths with excellent and consistent results.     

A study of multiple full-face treatments with low-energy settings of a 2940-nm Er:YAG fractionated laser

Abstract

Background and objective: Fractional Er:YAG 2940-nm laser resurfacing is a relatively new approach to the treatment of photodamaged skin. Typically, this approach uses fairly high delivered energies in order to create ‘microscopic wounds’ of tissue coagulation at various dermal depths. The purpose of this study was to evaluate the efficacy, safety and tolerability of low-energy, multiple-treatment, fractional Er:YAG laser resurfacing for the treatment of photoaged skin. Methods: Sixteen subjects with photoaged skin received six, lower-fluence laser treatments with a 2940-nm wavelength Er:YAG laser, using a fractionated handpiece and a maximum energy of 30 mJ per micro-spot. Subject satisfaction, treatment tolerability, and subject outcome assessment were performed. Results: Of the 12 subjects who completed the trial, all recorded improvement in their treated skin; half reported over 50% improvement. Most patients reported none or only mild stinging and burning during and after treatment. There was no downtime associated with the procedure. No adverse events were reported. Patient satisfaction rates were high. Conclusion: Low-energy, multiple treatment, 2940-nm Er:YAG laser resurfacing with this novel device is a safe and well-tolerated method for the treatment of superficial to moderate photoaged skin.     

Energy-based devices in the treatment of acne scars in skin of color

Background

Acne scarring is disfiguring and psychologically taxing on patients. Many energy-based modalities have emerged and been studied for the treatment of acne scarring; however, there is a paucity of these studies in skin phototypes IV–VI.

Objective

To review the medical literature and discuss the most significant studies regarding safety and efficacy of energy-based devices (ablative lasers, non-ablative lasers, and radiofrequency microneedling) in the treatment of ethnic skin (skin phototypes IV–VI).

Methods

A literature search was conducted using the PubMed database and bibliographies of relevant articles.

Results

Ablative and non-ablative lasers have proven to be effective for treatment of acne scars in ethnic skin. The risk of developing adverse effects such as post-inflammatory hyperpigmentation is contingent upon several factors including skin phototype, laser device, fluence, and moreso density settings. Non-ablative fractional lasers have been considered first line for the treatment of acne scars in skin of color due to their better safety profile; however, they are less efficacious and require more treatments compared to ablative lasers. Studies regarding efficacy and safety of radiofrequency microneedling for treatment of acne scarring in skin of color are limited, but are promising.

Conclusion

Ablative lasers, non-ablative lasers, and radiofrequency microneedling are all useful treatments for acne scarring in ethnic skin when appropriate settings are used. Further head-to-head studies are needed to evaluate their efficacy and safety in darker skin phototypes V–VI.     

Lasers in skin resurfacing

Laser skin resurfacing has revolutionized the approach to facial skin rejuvenation over the last decade. It has also added an approach to managing both atrophic and hypertrophic scars. This paper will review the basic principles of laser skin resurfacing, the different lasers used, the approach to treatment and potential complications of the procedure, followed by a discussion of future prospects in the field.     

Histology of ex vivo skin after treatment with fractionated picosecond Nd:YAG laser in high and low-energy settings

ABSTRACT

Background: The fractionated picosecond laser produces microscopic lesions in the epidermis and dermis, which are known as laser-induced optical breakdown (LIOB) and intra-dermal laser-induced cavitation (LIC). There have been multiple histological reports on these phenomena, although some have been challenged on the grounds of similarity to artifacts. Asian skins, with a higher melanin content, may react differently to this treatment, and present literature is also lacking in this area.

Purpose: To observe and report the histological effect of different energy levels and parameters of the fractional 532 nm/1064 nm picosecond laser on Asian skin ex vivo.

Methods: Six skin samples were taken from clinically normal-looking perilesional areas and treated with different energy levels and parameters of the fractional 532 nm/1064 nm picosecond laser. The specimens were then sent to the lab for H&E staining, and the slides were reviewed by a dermatopathologist.

Results: Superficial, intra-epidermal LIOBs were seen in skin treating at higher laser energies; deep, intra-dermal LICs were seen in skin treated at lower energies. Lesion sizes and depths were consistent with previously reported values on Caucasian skins, and lesions were spaced in 600-μm intervals or its multiple.

Conclusions: The histological findings are consistent with results from other ethnicities, and the spacing of lesions is a strong indication of their validity as LIOBs or LICs.     

Histologic analyses on the response of the skin to 1,927-nm fractional thulium fiber laser treatment

Background: The histologic responses to varied parameters of 1,927-nm fractional thulium fiber laser treatment have not yet been sufficiently elucidated. Objective: This study sought to evaluate histologic changes immediately after 1,927-nm fractional thulium fiber laser session at various parameters. Methods: The dorsal skin of Yucatan mini-pig was treated with 1,927-nm fractional thulium fiber laser at varied parameters, with or without skin drying. The immediate histologic changes were evaluated to determine the effects of varying laser parameters on the width and the depth of treated zones. Results: The increase in the level of pulse energy widened the area of epidermal changes in the low power level, but increased the dermal penetration depth in the high power level. As the pulse energy level increased, the increase in the power level under the given pulse energy level more evidently made dermal penetration deeper and the treatment area smaller. Skin drying did not show significant effects on epidermal changes, but evidently increased the depth of dermal denaturation under both high and low levels of pulse energy. Conclusion: These results may provide important information to establish treatment parameters of the 1,927-nm fractional thulium fiber laser for various skin conditions.     

Skin tightening induced by fractional CO(2) laser treatment: Quantified assessment of variations in mechanical properties of the skin

Background Certain authors have reported the efficacy of fractional resurfacing laser treatment in patients with photodamaged skin resulting in skin tightening of treated area. Objective To assess skin tightening after CO₂ fractional resurfacing laser treatment by measuring variations in mechanical properties in treated areas. Dermal elasticity was measured using suction applied with an in vivo skin elasticity meter (Cutometer^®). Methods A prospective observational study was undertaken from January 2007 to August 2009. Laser treatment was performed with the SmartXide Dot^® (Deka^®, Firenze, Italy) CO₂ fractional resurfacing device. Patients were offered quantified analysis using the Cutometer^® before and after treatment. Results Seventeen patients (61 areas treated) were included in the study. Median delay between before and after cutometric evaluations was 80 days. We found significant improvement in elastic (R2 +5.9%), viscoelastic (R8 ?9.4%), fatigue (R3 and R9 ?16.2% and ?19.7%, respectively), and thickness (R0 ?14.9%) parameters. These results are consistent with significant tightening and also elastic tissue improvement. Conclusions It was possible to quantify skin tightening because of CO₂ fractional laser treatment using a noninvasive technique.     

Superficial erbium:YAG laser resurfacing of photodamaged skin

Background: Light chemical peels and microdermabrasion have enjoyed recent popularity for the treatment of mild photoaging. However, clinical improvement from these modalities is often minimal from both a patient's and physician's perspective. Erbium:YAG lasers have been effective in treating mild to moderate photoaging, but the need for either regional or general anesthesia, as well as the significant post‐treatment recovery period has limited its use.

Objective: We sought to utilize a very low fluence approach to erbium:YAG laser resurfacing, with topical anesthesia, to ascertain its efficacy in treating mild to moderate photoaging.

Methods: A total of 250 subjects aged 28–80 years with skin types 1–4 and mild to moderate facial rhytids were treated with topical anesthesia and subsequently one pass of a 2940?nm erbium:YAG laser, using between 5 and 17.5?J/cm². In addition, 58 of the treated facial subjects underwent neck resurfacing with fluences between 5 and 15?J/cm² and eight treated facial subjects underwent upper chest resurfacing at fluences of 5–7?J/cm². A single treatment was received by 246 subjects; four subjects were treated a second time after a 1‐month interval.

Results: Most subjects completely re‐epithelialized by 3–4 days; healing time was depth dependent. Most subjects were able to start skin care regimens within 1–2 weeks after the procedure. Results were judged to be excellent in individuals with thin skin and good in subjects with thicker skin.

Conclusions: One pass of low fluence erbium:YAG resurfacing, under topical anesthesia, was effective for the treatment of mild to moderate photoaging.     

Laser therapy of a dermal nevus in the esthetic zone of the nasal tip: A case report and comprehensive literature review

This case report demonstrates the ablation of a dermal nevus using a diode laser in the esthetically very demanding facial area of the nasal tip. The clinical outcome shows good results and a high level of patient satisfaction. Due to effective wound granulation and healing, elaborate skin grafts could be avoided. The application of the contact laser ensures safe treatment in highly perfused areas thanks to haptic feedback and good coagulative effect. The method should therefore be considered as an alternative to other ablative procedures for benign lesions in the facial area.     

The dual 980‐nm and 1470‐nm diode laser for vascular lesions

Transcutaneous use of dual diode lasers is a new option in dermatology. The aim of the study was to demonstrate the transcutaneous application of a dual laser in dermatologic outpatients. We used a laser system that combines 980 nm and 1470 nm wavelengths for treatment of vascular lesions. Fifty‐six adult Caucasian patients of Fitzpatrick skin type I‐III, 32 females and 24 males with mean age of (41 ± 3.7) years were included. We treated 497 vascular lesions of skin and lips. Complete clearance was achieved in cherry angiomas, venous lakes, lip hemangioma, and spider nevi in 100% after a single treatment. Patients with couperose and/or facial telangiectasia needed several treatment sessions. Mild to moderate pain during the laser shots was noted in all patients. No adverse events were recorded. The dual 980‐nm/1470‐nm diode laser is a safe and effective tool for common vascular lesions.     

1320nm激光对小鼠皮肤组织病理和生理特性的影响

目的:研究1320 nm激光对小鼠皮肤组织病理和部分皮肤生理指标的影响。方法:用该波长激光对小鼠背部皮肤照射,于照射前、照射后1 h3、d7、d、15 d、30 d取皮肤做病理,同时用MPA皮肤多功能测试系统测定其皮肤回声值、黑素含量、皮肤血红蛋白含量、经皮失水量、表皮含水量和皮脂含量。结果:激光照射后1 h,真皮纤维组织排列致密。照射后3 d,真皮炎症细胞和成纤维细胞增多。照射后15 d真皮层增厚、胶原增加。激光照射后短期内对于皮肤弹性、皮肤血红蛋白含量、经皮失水量、皮脂含量、表皮含水量,均有一定程度暂时性影响,对皮肤黑素含量无影响。结论:1320 nm激光可引起小鼠成纤维细胞增生和胶原蛋白合成增加,改善皮肤弹性,但在短期内对皮肤生理状态可产生一定的负面影响。     

Histological hair removal study by ruby or alexandrite laser with comparative study on the effects of wavelength and fluence

BACKGROUND: Several different laser systems are currently used to remove unwanted hairs. In this study, we studied follicular changes following hair removal with ruby or alexandrite lasers at different fluences.

METHODS: Unwanted hairs were treated with a ruby laser (Chromos 694, ICN PhotonIcs, UK) at 10, 14 or 18?J/cm² or with an alexandrite laser (LPIR, Cynosure, USA) at 11, 14 or 17?J/cm². A 3?mm skin punch biopsy was taken immediately after each laser exposure and also 1 month later. Specimens were stained for histological observation. They were observed using immunohistochemistry with antibodies recognizing factor VIII related antigen or PCNA, and also by the TUNEL method. Similarly, electron microscopic observation was examined.

RESULTS: Immediately after the laser exposure, moderate follicular damage was observed following treatment with either type of laser. One month later, cystic formation of hair follicles and foreign body giant cells were observed in skin treated with either type of laser. A similar fluence with either laser treatment resulted in similar histological changes.

CONCLUSION: In this study, the histological changes following treatment with a ruby or an alexandrite laser at the same fluence are similar.     

Facial resurfacing using a high-energy, short-pulse carbon dioxide laser

Facial skin resurfacing is now possible using short-pulse, high-energy carbon dioxide (CO₂) lasers. The laser utilized in this particular paper is the Ultrapulse CO₂ laser. The Ultrapulse laser represents the first CO₂ laser able to vaporize tissue in a single pulse with the use of a large spot size. This laser utilizes the principles of selective photothermolysis. The high-power pulses are completed in less than the thermal relaxation time of skin, estimated to be less than 1 millisecond. This translates into rapid vaporization of tissue with little heat conduction to surrounding tissues. It also should allow a reproducibility of results between practitioners with set parameters not possible with previous CO₂ lasers. Clinically, this laser is useful for the removal of skin lesions, and the resurfacing of areas of sun damage, wrinkles and scars. The immediate haemostasis and excellent visibility allows for precise vaporization of abnormal tissue. Rapid and pain-free wound healing is usual. The complication rate would appear to compare very favourably with dermabrasion and chemical peeling techniques.     

Syringoma of the face treated with fractional photothermolysis

Abstract

We experienced that two Japanese women diagnosed with syringoma, confirmed by a punch biopsy, were successfully treated with fractional resurfacing. Both clinical cases have had positive results after only a few treatments, with high patient satisfaction, not only for the improvement of syringoma, but also for the improvement of aging skin, and with no side effects. From that aspect, laser treatment with fractional photothermolysis may be considered to be one of the effective treatment methods for syringoma. Although fractional photothermolysis was originally developed for an aesthetic purpose, it also can be utilized for intractable skin disease, as demonstrated by taking the concept of fractional photothermolysis and the results from this study with skin biopsy.     

Alexandrite laser hair removal results in 2359 patients: A Turkish experience

Background: Various lasers have been developed for epilation of unwanted hair. Effective hair removal in the Turkish population can be difficult, and multiple treatments are usually required for effective treatment. Objective: To evaluate the safety and efficacy profile of a long-pulsed alexandrite laser for hair removal in the Turkish population with Fitzpatrick skin types II–V exclusively and to determine the benefit of multiple treatments. Methods: Retrospective clinical evaluation conducted from September 2005 to May 2008 at a referral private clinic. Pre-laser skin testing was performed starting at 16 J/cm² and the energy fluence was selected according to response. All subjects were followed for 6 months after their final treatment. Results: A total of 2359 patients are reported (264 men and 2095 women) ranging in age from 14 to 70 years, for a total of 3830 treatment sites. The majority of treatment sites were axillae (24.2%) followed by the bikini line (16.8%). Maximum reductions observed were 95% for axillae, 92% for the bikini line, 86% for breast, respectively. The patients had a mean 80.6% hair reduction. Complications occurred in only 2.2% of cases. Transient hyperpigmentation (0.7%), folliculitis (0.5%), transient hypopigmentation (0.5%), and blistering (0.4%) were commonly seen complications. No subjects had scarring or long-term pigmentary changes. Conclusion: The long-pulsed alexandrite laser is safe for hair removal in darker skin tones. Although Turkish skin can be effectively treated with a cooled, long-pulsed alexandrite laser, complications do occur.     

橙皮苷、β-七叶皂苷、丹参酮等局部外用对甲皱皮肤微循环的影响

目的：研究局部外用8种天然植物提取物对皮肤微循环的影响。方法：给受试者中指甲皱处分别涂1％植物提取物,并安放激光多普勒检测探头,稳定5min后开始记录甲皱皮肤血流灌注量,以后每5min记录1次,每次1min,共观察30min取平均值。基质作对照。对有效成分进一步观察浓度为0．10％、0．01％药物对皮肤血液灌注量的影响,并用毛细血管微循环仪观察其对红细胞血流速度的影响。结果：1．00％、0．10％橙皮苷可以显著增加皮肤的血液灌注量,外用0．10％橙皮苷亦可使红细胞的血流速度显著增加。结论：橙皮苷局部外用可以改善皮肤的微循环。     

A new surgical approach for the treatment of severe epithelial skin sun-induced damage

BACKGROUND: Cutaneous photoageing is a complex biological process affecting all layers of the skin. Skin damage resulting from intrinsic ageing and extrinsic photoageing may trigger skin cancer. In patients with advanced photoageing and/or diffuse actinic damage, local therapy is often inadequate and the possibility of combined therapy needs to be assessed. SUBJECTS: Here we report three cases of patients over 75 years of age with advanced diffuse epithelial skin damage of photoexposed areas consisting of several superficial actinic keratoses, ipermelanotic lesions and multiple skin cancers. METHODS: Neoplastic lesions and damaged skin were removed by superficial erbium laser ablation and the epidermis reconstructed with autologous epidermal sheets expanded in vitro from healthy cells obtained from unexposed areas of the body. RESULTS: Our initial studies show that this procedure is very effective in the short term for treating and preventing the UV-induced skin cancer and precancerous lesions, and also suggest good long-term control of the disease with very interesting aesthetic results.     

Glove powder affects skin roughness, one parameter of skin irritation

Most patients with immediate-type-hyper sensitivity to natural rubber latex (NRL) give a history of hand eczema. Susceptibility to allergens is increased by irritant hand eczema due to damage to the skin barrier. Therefore, especially for employees in medical or paramedical professions, reduction in skin irritation is of importance. The present study reports the effect of glove powder on skin roughness, one feature of skin irritancy. Skin replicas, performed before and after wearing different types of gloves, were evaluated by laser profilometry. Significant alteration of skin roughness was evident and determined by different factors. Use of unpowdered Biogel gloves on prepowdered hands results in an increase in skin roughness, in contrast to the use of Biogel gloves on hands without any pre-application. On the other hand, powdered Manex neoderm gloves show no influence on the skin structure, whereas powdered Peha taft gloves also increase the roughness of the skin. Other potential candidates causing skin morphology alteration could be the glove pH, rubber chemicals with irritant potential and other characteristics of gloves, which are already under investigation.     

Wavelength effects on contrast observed with reflectance in vivo confocal laser scanning microscopy

Background/purpose: The ability to optically section live biological tissue in vivo with laser light is made possible by confocal laser scanning microscopy (CLSM). In this work, the effects of changing the wavelength of incident light used for CLSM imaging of human skin are reported and analyzed.
Methods: Optical phantoms and the skin of eight human volunteers were imaged using CLSM systems having three different incident light wavelengths (405, 785, and 830 nm).
Results: Qualitative and quantitative differences were observed between images obtained at each wavelength, despite the proximity of the two near infrared 785 and 830 nm wavelengths. Furthermore, the penetration depth achieved with the 405 nm CLSM permitted imaging into the papillary dermis.
Conclusion: The laser wavelength used in CLSM reflectance imaging is important to properly understand and resolve different biological structures within human skin.