Hair growth cycle affects hair follicle destruction by ruby laser pulses

The effect of long-pulsed 1064 nm Nd:YAG laser-assisted hair removal on some skin flora and pathogens: an in vivo study

Background The effect of NDYag on normal skin flora and pathogenic microbes has not been studied. Objectives Evaluation of immediate (before versus after each session) and delayed (pre-first session versus pre-fourth session) antimicrobial effect of Nd:YAG laser-assisted hair removal. Methods Thirty females scheduled for axillary Nd:YAG laser hair removal were included. Skin swabs were collected from the vault of the dominant axilla before and after each of the four sessions. Bacteriological cultures were performed to record the counts of total aerobes, total anaerobes, lipophilic bacteria, total staphylococci, Staphylococcus epidermidis (S. epidermidis), S. saprophyticus, S. hominis, and S. aureus. Reported changes in sweat odour and folliculitis (if present) were recorded. Results S.hominis was the predominant species in all subjects before and after all sessions. Counts of total aerobes, total anaerobes, lipophilic bacteria, total staphylococci, and S.hominis significantly decreased after all 4 sessions. A significant reduction was noted in the median colony counts before the fourth session as compared to the baseline count before the first session in total aerobes (278.9 versus 126.3 × 105 CFU/cm2, p = 0.003), total anaerobes (338.7 versus 103.7 × 105 CFU/cm2, p = 0.002) and total staphylococci (248.5 versus 105.0 × 105 CFU/cm2, p = 0.004). Most subjects reported worsened or unchanged axillary sweat odour. There was a statistically significant positive correlation between sweat odour and the counts of total aerobes (r = 0.433, p = 0.017), total anaerobes (r = 0.377, p = 0.040), total staphylococci (r = 0.383, p = 0.036) and S.hominis (r = 0.497, p = 0.005) ; lower counts were associated with a worsened odour. Limitations Small sample size; few laser sessions; short follow-up; subjective assessment of sweat odor and quantity. Conclusions Laser caused an immediate and delayed reduction in axillary aerobes, anaerobes, lipophilic bacteria, and staphylococci. This form of dysbiosis might lead to sweat odour changes.

Depilatory laser miniaturizes hair by inducing bystander dermal papilla cell necrosis through thermal diffusion

OBJECTIVES

Depilatory laser targeting melanin has been widely applied for the treatment of hypertrichosis. Both selective photothermolysis and thermal diffusion have been proposed for its effect, but the exact mechanism of permanent hair reduction remains unclear. In this study, we explore the role of thermal diffusion in depilatory laser-induced permanent hair loss and determine whether nonpigmented cells are injured by thermal diffusion.

MATERIALS AND METHODS

C57BL/6 mice in anagen and telogen were treated with alexandrite laser (wavelength 755 nm, pulse duration 3 milliseconds, fluence 12 J/cm² , spot size 12 mm), respectively. Histological analysis, terminal deoxynucleotidyl transferase dUTP nick-end labeling assay, and transmission electron microscopic imaging were employed to evaluate the injury to hair follicle (HF) cells. The proliferation status of HF cells was examined by 5-bromo-2'-deoxyuridine pulse labeling. The number of HF stem cells was quantified by fluorescence-activated cell sorting. The size of the regenerated hair was determined by measuring its length and width.

RESULTS

We found that irradiating C57BL/6 mice in anagen with alexandrite laser led to hair miniaturization in the next anagen. In addition to thermal disruption of melanin-containing cells in the precortex region, we also detected necrosis of the adjacent nonpigmented dermal papilla cells due to thermal diffusion. Dermal papilla cells decreased by 24% after laser injury, while the number of bulge stem cells remained unchanged. When the laser was delivered to telogen HFs where no melanin was present adjacent to the dermal papilla, thermal necrosis and cell reduction were not detected in the dermal papilla and no hair miniaturization was observed.

CONCLUSION

Our results suggest that depilatory laser miniaturizes hair by inducing thermal necrosis of dermal papilla cells due to secondary thermal diffusion from melanin-containing precortex cells in the anagen hair bulbs.

Das schöne, glatte Bein: Haarentfernung durch Laser und lichtbasierte Verfahren

Die Fotoepilation zählt zu den meistgefragten nichtchirurgischen Eingriffen in der ästhetischen Dermatologie. Haarlose, glatte Beine gelten dabei als Schönheitsideal.

Fotoepilation mittels Laser oder hochenergetischer Blitzlampen (sog. Intensed-Pulsed-Light-Geräte) stellt ein sicheres und effektives Verfahren dar. Der Wirkmechanismus beruht auf dem Prinzip der selektiven Fotothermolyse, wobei eine gezielte thermische Schädigung pigmentierter Haarfollikel unter Schonung des umliegenden Gewebes erfolgt. Melaninpigment des Haarschaftes absorbiert als Zielchromophor Licht eines speziellen Wellenlängenspektrums und führt durch Wärmediffusion zur Schädigung der für das Haarwachstum wichtigen Stammzellen im äußeren Haarwurzelschaft.

Patienten müssen über die Notwendigkeit wiederholter Behandlungen sowie den häufig nur partiellen und temporären Haarverlust aufgeklärt werden. Dunkle Terminalhaare bei hellen Hauttypen lassen sich effektiv entfernen. Bei dunklen Hauttypen besteht aufgrund des erhöhten epidermalen Melaninvorkommens ein erhöhtes Risiko für Nebenwirkungen wie Verbrennungen, Dyspigmentierungen und Narben. Sehr feine, helle oder rote Haare lassen sich kaum mit konventionellen Fotoepilationsverfahren entfernen. Haarentfernungsgeräte für den Heimgebrauch sind eine kostengünstige, einfach anzuwendende Alternative, weisen aber im Vergleich zur professionellen Fotoepilation eine geringere Effektivität auf.

Efficacy & safety of intense pulsed light therapy for unwanted facial hair: a retrospective analysis in skin of color

Unwanted facial hair growth is a common esthetic problem. Laser hair removal has emerged as a leading treatment option for long-term depilation. The theory of selective photothermolysis has revolutionized laser hair removal in that it is effective and safe, when operated by sufficiently trained and experienced professionals. Long-pulsed ruby (694 nm), long-pulsed alexandrite (755 nm), diode (800-980 nm), and long-pulsed Nd: YAG (1064) are commercially available laser devices for hair removal most widely studied. The authors wish to share the efficacy and safety of intense pulse light therapy for permanent facial hair reduction in Indian population.

Das schöne, glatte Bein: Haarentfernung durch Laser und lichtbasierte Verfahren

Die Fotoepilation zählt zu den meistgefragten nichtchirurgischen Eingriffen in der ästhetischen Dermatologie. Haarlose, glatte Beine gelten dabei als Schönheitsideal.

Fotoepilation mittels Laser oder hochenergetischer Blitzlampen (sog. Intensed-Pulsed-Light-Geräte) stellt ein sicheres und effektives Verfahren dar. Der Wirkmechanismus beruht auf dem Prinzip der selektiven Fotothermolyse, wobei eine gezielte thermische Schädigung pigmentierter Haarfollikel unter Schonung des umliegenden Gewebes erfolgt. Melaninpigment des Haarschaftes absorbiert als Zielchromophor Licht eines speziellen Wellenlängenspektrums und führt durch Wärmediffusion zur Schädigung der für das Haarwachstum wichtigen Stammzellen im äußeren Haarwurzelschaft.

Patienten müssen über die Notwendigkeit wiederholter Behandlungen sowie den häufig nur partiellen und temporären Haarverlust aufgeklärt werden. Dunkle Terminalhaare bei hellen Hauttypen lassen sich effektiv entfernen. Bei dunklen Hauttypen besteht aufgrund des erhöhten epidermalen Melaninvorkommens ein erhöhtes Risiko für Nebenwirkungen wie Verbrennungen, Dyspigmentierungen und Narben. Sehr feine, helle oder rote Haare lassen sich kaum mit konventionellen Fotoepilationsverfahren entfernen. Haarentfernungsgeräte für den Heimgebrauch sind eine kostengünstige, einfach anzuwendende Alternative, weisen aber im Vergleich zur professionellen Fotoepilation eine geringere Effektivität auf.

Micro-Current Stimulation Has Potential Effects of Hair Growth-Promotion on Human Hair Follicle-Derived Papilla Cells and Animal Model

Recently, a variety of safe and effective non-pharmacological methods have been introduced as new treatments of alopecia. Micro-current electrical stimulation (MCS) is one of them. It is generally known to facilitate cell proliferation and differentiation and promote cell migration and ATP synthesis. This study aimed to investigate the hair growth-promoting effect of MCS on human hair follicle-derived papilla cells (HFDPC) and a telogenic mice model. We examined changes in cell proliferation, migration, and cell cycle progression with MCS-applied HFDPC. The changes of expression of the cell cycle regulatory proteins, molecules related to the PI3K/AKT/mTOR/Fox01 pathway and Wnt/β-catenin pathway were also examined by immunoblotting. Subsequently, we evaluated the various growth factors in developing hair follicles by RT-PCR in MCS-applied (MCS) mice model. From the results, the MCS-applied groups with specific levels showed effects on HFDPC proliferation and migration and promoted cell cycle progression and the expression of cell cycle-related proteins. Moreover, these levels significantly activated the Wnt/β-catenin pathway and PI3K/AKT/mTOR/Fox01 pathway. Various growth factors in developing hair follicles, including Wnts, FGFs, IGF-1, and VEGF-B except for VEGF-A, significantly increased in MCS-applied mice. Our results may confirm that MCS has hair growth-promoting effect on HFDPC as well as telogenic mice model, suggesting a potential treatment strategy for alopecia.

Trichogenic Photostimulation Using Monolithic Flexible Vertical AlGaInP Light-Emitting Diodes

Alopecia is considered an aesthetic, psychological, and social issue among modern people. Although laser-induced skin stimulation is utilized for depilation treatment, such treatment has significant drawbacks of high energy consumption, huge equipment size, and limited usage in daily life. Here, we present a wearable photostimulator for hair-growth applications using high-performance flexible red vertical light-emitting diodes (f-VLEDs). Flexible microscale LEDs were effectively fabricated by a simple monolithic fabrication process, resulting in high light output (∼30 mW mm^-2), low forward voltage (∼2.8 V), and excellent flexibility for wearable biostimulation. Finally, trichogenic stimulation of a hairless mouse was achieved using high-performance red f-VLEDs with high thermal stability, device uniformity, and mechanical durability.

Nonpigmented hair removal using photodynamic therapy in animal model

BACKGROUND AND OBJECTIVE

Lasers have been successfully used for decades to remove dark hair. However, laser removal of nonpigmented hair is challenging due to the lack of chromophores. The aim of this study was to use photodynamic therapy (PDT) to remove nonpigmented hair.

STUDY DESIGN/MATERIAL AND METHODS

We compared the efficacy of permanent hair reduction in white BALB/c and black C57BL/6 mice treated with PDT or an 800-nm diode laser. We collected skin biopsy specimens and investigated post-PDT histologic changes and molecular changes.

RESULTS

We observed keratin 15 staining in the bulge area and alkaline phosphatase staining in the dermal papilla following PDT. We observed a temporary, catagen-like transformation in nonpigmented hair follicles after PDT. We observed apoptotic cells in the hair matrix after PDT. Irradiation with an 800-nm diode laser did not achieve nonpigmented hair removal. Multiple PDT sessions achieved permanent reduction of nonpigmented hair. Interestingly, removal of black hair using PDT was less efficient.

CONCLUSION

Our results suggest that PDT can damage the nonpigmented hair matrix, but not stem cells or dermal papillae. Repeated PDT may impair the hair-regeneration capacity via a bystander effect on bulge stem cells or dermal papillae. In this study, we found it was possible to remove nonpigmented hair using PDT. Lasers Surg. Med. 48:748-762, 2016. © 2016 Wiley Periodicals, Inc.

Safety and efficacy of low fluence, high repetition rate versus high fluence, low repetition rate 810-nm diode laser for axillary hair removal in Chinese women

BACKGROUND

High-fluence diode lasers with contact cooling have emerged as the gold standard to remove unwanted hair. Lowering the energy should result in less pain and could theoretically affect the efficacy of the therapy.

OBJECTIVE

To compare the safety and efficacy of a low fluence high repetition rate 810-nm diode laser to those of a high fluence, low repetition rate diode laser for permanent axillary hair removal in Chinese women.

METHODS

Ninety-two Chinese women received four axillae laser hair removal treatments at 4-week intervals using the low fluence, high repetition rate 810-nm diode laser in super hair removal (SHR) mode on one side and the high fluence, low repetition rate diode laser in hair removal (HR) mode on the other side. Hair counts were done at each follow-up visit and 6-month follow-up after the final laser treatment using a "Hi Quality Hair Analysis Program System"; the immediate pain score after each treatment session was recorded by a visual analog scale.

RESULTS

The overall median reduction of hair was 90.2% with the 810-nm diode laser in SHR mode and 87% with the same laser in HR mode at 6-month follow-up. The median pain scores in SHR mode and in HR mode were 2.75 and 6.75, respectively.

CONCLUSION

Low fluence, high repetition rate diode laser can efficiently remove unwanted hair but also significantly improve tolerability and reduce adverse events during the course of treatment.

Objective evaluation of photoepilation by phototrichogram

Photoepilation is one of the most popular cosmetic procedures. However, there has been no objective method to evaluate the efficacy of hair removal. The goal of this study is to evaluate the effect of photoepilation more objectively using a phototrichogram method. Thirteen young, healthy, female volunteers were enrolled in this study. At initial work-up, semi-permanent tattoos were marked in both axillae of all the volunteers and hair variables were evaluated by phototrichogram and digital camera. Intense pulsed light-assisted photoepilations were performed in both axillae of the volunteers twice at 4-week intervals. At each visit, dermatologists checked changes of hair parameters. Clinically, 8 weeks after two treatments, hair reduction of all patients was achieved. Total hair counts, changes of anagen ratio, non-vellus hair counts, hair density, anagen growth rate and hair diameter were decreased sequentially and the reduction was statistically significant. No correlations were found between power, pain, patient and doctor evaluations at 4 weeks. Doctor evaluations correlated with anagen hair counts, anagen/total hair ratio, anagen/telogen ratio and total growth rate. Using phototrichograms could be an objective evaluation technique for hair removal. Anagen parameters and total growth rate of hairs in phototrichograms may be able to be predictable values for evaluating epilation.

Biological and clinical aspects in laser hair removal

INTRODUCTION

In the past century, unwanted hair has been traditionally treated with multitudes of techniques that were found to be slow, tedious, painful, impractical, and resulted in poor long-term efficacy. Consequently, there has been a public demand for a novel, rapid, reliable, safe, and affordable hair removal technique. In the last decade, laser and light-based technology for hair removal became one of the fastest growing procedures in modern cosmetic dermatology.

OBJECTIVE

To discuss the latest scientific and clinical issues in the field of photoepilation as evolved in the past decade: hair biology, laser physics and skin optics, technology and clinical experience.

RESULTS

From substantial clinical experience, it becomes apparent that in the ideal subject with fair skin and dark hair, a single treatment can reduce hair by 10-40%; three treatments by 30-70%; and repeated treatments by as much as 90%. These results persist for as long as 12 months. Diffuse and perifollicular cutaneous erythema and pigmentary changes are the most common adverse side effects. Most complications are generally temporary.

CONCLUSIONS

Photoepilation, when properly used, offers clear advantages when compared with older, traditional techniques. Although an ever-increasing number of published studies have confirmed the safety and short and long-term efficacy of photoepilation, the technology still has limits and risks.

A structured treatment protocol improves results with laser hair removal

BACKGROUND

As laser epilation has become a widely accepted method for hair removal, questions regarding timing and frequency of treatments have arisen.

OBJECTIVE

To determine whether a structured treatment protocol for laser hair removal improves clinical results in reducing hair growth.

METHODS

A group of 100 patients (Group A) underwent laser epilation with four regularly spaced treatments; a group of 100 patients (Group B) determined their own treatment plan with respect to timing and frequency (not exceeding four treatments).

RESULTS

Group A experienced a 78 +/- 8% reduction in hair with four treatments per patient while Group B experienced a 48 +/- 12% reduction with an average of 2.5 +/- 0.5 treatments per patient. These differences were statistically significant (P < 0.05). Patient satisfaction was significantly improved in Group A compared with Group B (P < 0.05). A positive linear relationship was identified in Group B between treatment frequency and hair reduction (r = 0.94) and between treatment frequency and patient satisfaction (r = 0.89).

CONCLUSION

This study concludes that patients who participate in a structured treatment protocol note superior clinical results following laser hair removal.

[Photoepilation: state-of-the-art]

The field of dermatological laser medicine consists of four main areas: therapy for blood vessels, therapy for pigmented lesions, ablation of tissue, and photoepilation. The first tests were carried out in 1993, and since 1996 there has been a growing demand for "permanent hair removal." This strong demand and the rapid development of devices call for extensive knowledge in terms of current technical innovation or affirmation of proven procedures. This article gives a general survey of the different systems that can be used for "permanent hair removal" [ruby laser, alexandrite laser, diode, Nd:YAG laser, so-called intense pulsed light (IPL) systems, and combined radio frequency/IPL systems], including their inherent advantages and disadvantages. Physical and biological aspects necessary for photoepilation are pointed out. Furthermore, we emphasize new methods concerning removal of depigmented and therapy-resistant hair, as well as the treatment of female patients with polycystic ovary syndrome.

Mechanisms of Laser Hair Removal: Could Persistent Photoepilation Induce Vitiligo or Defects in Wound Repair?

BACKGROUND

Current laser hair removal modalities achieve a long-term but not persistent (irreversible) hair loss.

OBJECTIVE

This review highlights the mechanisms of the current laser hair removal technology and explores possible side effects.

METHODS

The literature is reviewed.

RESULTS

The hair shaft plays a key role in the mechanisms underlying current photoepilation procedures by acting as a vector for heat transfer. Together with inherent properties of the hair growth cycle and the anatomic specifics of the follicular stem cells located in the bulge, the crucial role of the hair shaft and its lack of complete destruction with present technology are also likely culprits for the nonpersistent nature of present laser hair removal. Future persistent photoepilation may be associated with vitiligo or vitiligolike changes. Disturbances in wound repair of previously lasered sites are less likely.

CONCLUSIONS

The currently available laser hair removal protocols are safe, not the least because they achieve long-term but not persistent epilation. The adverse effects of persistent laser hair removal technology possibly available in the future are potentially problematic.

Simulated consumer use of a battery-powered, hand-held, portable diode laser (810 nm) for hair removal: A safety, efficacy and ease-of-use study

BACKGROUND AND OBJECTIVES

Safety, efficacy and ease-of-use of a hair removal diode laser for consumer use were evaluated.

STUDY DESIGN/MATERIALS AND METHODS

The treatment group consisting of 77 appropriate users measured safety and efficacy from three self-administered treatments. The non-treatment group consisting of 44 inappropriate users measured safety from delivery of a single laser pulse.

RESULTS

The mean hair reduction was 61% 3 weeks after the first treatment, 70% 3 weeks after the second treatment, 60% 1 month after the third treatment, 24% 2 months after the third treatment, 6% 3 months after the third treatment, 41% 6 months after the third treatment, 31% 9 months after the third treatment, and 33% 12 months after the third treatment. The only observed side effect for appropriate users was transient erythema.

CONCLUSIONS

In simulated consumer use, the laser was highly effective at removing hair with minimal side effects for appropriate users.

Photoepilation: a potential threat to wound healing in a mouse

BACKGROUND

Theoretically, the bulge area which is known to be a reservoir of epidermal stem cells should be destroyed to achieve permanent photoepilation. We wished to determine whether wound healing capability is perturbed after photoepilation.

METHODS

Twenty C57/BL6 mice were used. After wax epilation to synchronize the hair cycle, one-half of the backs of mice were photoepilated in the early anagen stage. After the two hair cycles of the mice to confirm the hair removal effect, 30% trichloroacetic acid was applied to the both halves of the backs of the mice. A skin biopsy was performed on both sides before and just after the injury, and 2, 6, 9, and 14 days thereafter. The specimens were evaluated histologically after staining with hematoxylin and eosin, Masson trichrome, and Verhoeff-van Gieson.

RESULTS

No differences in wound healing times were evident upon gross observation by the naked eye. However, the photoepilated hairless skin was observed to have a thicker epidermis and dermis than normal hairy skin by histological evaluation. The cellularity of the healed wound was much denser in the photoepilated. Collagen production of the neodermis in the normal hairy skin was first observed around the lower part of hair follicle, while it started from the upper papillary dermis in photoepilated skin.

CONCLUSION

Photoepilation may disturb the normal wound healing process, especially dermal wound healing, and increases the risk of producing hypertropic scar or keloid.

Laser hair removal

Since 1996, there have been numerous advances in hair laser removal that utilize melanin as a chromophore. All of the devices on the market may be used in patients with light skin (phototypes I-III) and yield hair reduction near 75%. The ruby (694 nm) laser, alexandrite (755 nm) laser, and diode (810 nm) laser, as well as intense pulsed light are commonly used devices for hair laser removal. The long-pulsed Nd:YAG (1064 nm) laser represents the safest device for hair removal in dark-skinned patients because of its long wavelength, although the diode laser, alexandrite laser, and intense pulse light may be used. For treatment of light hair, combination radiofrequency and optical devices as well as photodynamic therapy are under investigation.

Hair removal using an 800-nm Diode Laser: Comparison at different treatment intervals of 45, 60, and 90 days

BACKGROUND

Some laser irradiation parameters such as wavelength, fluence, pulse duration, and spot size have been shown to influence the damage of any target inside the skin, however, the role of some patients' factors such as hair growth cycle is still under debate.

OBJECTIVE

To determine the association of treatment interval and laser treatment outcome.

METHODS

In a retrospective chart review of 176 patients undergoing laser-assisted hair removal with a diode laser 24 patients were selected. All accepted to cease the therapy, and be followed-up for 5 months. At the end of the study the patients were questioned about the efficacy of the treatment as well as the adverse effects. Hair counting was also performed. The adverse effects (pain, blister or erosion, hyperpigmentation, hypopigmentation, and folliculitis) were questioned during the follow-up period.

RESULTS

The mean hair reduction was 78.1%, 45.8%, and 28.7% in 45, 60, and 90-day interval groups, respectively (P < 0.0001).

CONCLUSION

The treatment interval was related to the treatment outcome in our study.

Neodymium: yttrium-aluminum-garnet long impulse laser for the elimination of superfluous hair: experiences and considerations from 3 years of activity

This study examined the results obtained with a modern apparatus for laser hair removal (neodymium: yttrium-aluminum-garnet [Nd:YAG] laser at long impulses with a wave-length of 1,064 nm; Q-switched laser) over a follow-up period of 3 years. A large heterogeneous group of 480 patients was taken into consideration. These patients were treated according to a standard protocol with monthly checkups and a personalized protocol at deferred appointments. The results, discovered by means of the most objective procedure possible, were retrieved and put into a graph showing two different curves for the repopulation of hair. In their clinical travels, the authors observed an average variable regrowth of 40% to 65%, allowing them to affirm that laser hair removal using Nd:YAG at long impulses is decisively efficient in obtaining long-term results. The use of a protocol (denominated "prolonged monthly checkup") with laser sessions at ever-decreasing periods permits, among other things, more outstanding and advantageous results for the patient. Thanks to more efficiently synchronized phases of the biologic hair cycle, this shortens and moves the telegenic phases closer and also renders the anagenic phases (those in which the selective photoermolysis on the pilipheric follicle proves to be efficient) more efficient. Personalization of the treatment relative to the monthly health checkup sessions is of fundamental importance to the scope of obtaining the best results in terms of cost-benefit rate, provided submassimal fluxes are (i.e., those well-tolerated by the patient) used. All this allows hair removal that is not definitive, but which becomes progressively permanent (i.e., characterized by ever-growing periods of lack of hair sustained by sporadic maintenance laser sessions based on the individual's necessity).

Effect of wax epilation before hair removal with a long-pulsed alexandrite laser: a pilot study

BACKGROUND

Recent reports indicate that laser hair removal is most effective on anagen hairs. However, no published trials have examined laser epilation after hair cycle synchronization.

OBJECTIVE

To evaluate the potential for enhanced laser hair removal after the induction of telogen hairs into anagen by wax epilation.

METHODS

We identified four 2.5-cm square areas with equivalent hair length and density on the backs of 13 dark-haired white men. To induce typically telogen hairs into anagen, two areas on each patient were wax epilated. Two weeks later, one waxed area and one unwaxed area were treated with a long-pulsed alexandrite laser. One month after laser treatment, a subjective comparison was made based on hair density, length, and thickness.

RESULTS

In 12 of 13 patients, lasered areas that had been pretreated with wax epilation were clearer of hair as compared with areas that had been pretreated by shaving (P=0.0034). No significant difference was noted between waxed and unwaxed control areas that had not been laser treated (P=1.0).

CONCLUSION

Wax epilation 2 weeks before laser hair removal improves cosmetic outcomes at 1 month. This effect may be secondary to the recruitment and heightened sensitivity of early anagen hairs.

Patient satisfaction study of unwanted facial and body hair: 5 years experience with intense pulsed light

OBJECTIVE

This study was performed in order to evaluate patient satisfaction with epilation using an intense pulsed light source.

METHODS

Between 1995 and 2000, 416 patients consulted the authors' practice because of unwanted facial and body hair. A total of 309 patients received treatment with a non-coherent, filtered flashlamp intense pulsed light source. In February 2000, a questionnaire was mailed to each patient and 207 replies were obtained.

RESULTS

Overall, 45 (22%) of patients were very satisfied, 93 (45%) were satisfied and 69 (33%) remained unsatisfied with the outcome of light-assisted hair removal. The non-coherent, filtered flashlamp intense pulsed light source satisfactorily removed unwanted dark hair. Hair-free periods from weeks to years could be observed.

CONCLUSION

Hair removal by a non-coherent, filtered flashlamp intense pulsed light source is an effective and safe method for long-term epilation of unwanted hair. This technique offers a more reliable and practical solution than any other hair removal method, especially for patients with skin irritation and ingrown hair.

Long-pulsed ruby laser for permanent hair reduction: histological analysis after 3, 4 1/2, and 6 months

BACKGROUND AND OBJECTIVES

The histology of hair follicles in both animal and human skin treated with ruby lasers has been evaluated to a limited extent in previous studies. We have previously looked at such follicles up to 2 months after treatment. This study examines the longer-term effects at a microscopic level and attempts to further elucidate the mechanism of ruby laser hair reduction.

STUDY DESIGN/MATERIALS AND METHODS

Thirty-six patients underwent 1, 2, or 3 treatments of their axillary or bikini area skin with a 3 milliseconds ruby laser at 10, 20, 30, or 40 J/cm(2). Biopsies were taken 3, 4(1/2), or 6 months after the last treatment and examined histologically. Nine control biopsies were taken from comparable bikini areas of untreated patients and similarly evaluated histologically.

RESULTS

There was a significant increase in telogen compared to anagen follicles in treated skin, which was slightly increased by multiple compared to single treatments, but unaffected by different time intervals since the last treatment. There was also a significant increase in miniaturized compared to terminal hairs in treated compared to control skin, a finding that was further increased with higher energies used. Multiple treatments and time after treatment had a slight, but not statistically significant effect on follicle size.

CONCLUSIONS

Induction of telogen in terminal follicles followed by miniaturization appears to be the main mechanism of ruby laser hair reduction.

Laser treatment improves quality of life of hirsute females

Hirsutism has a significant impact on the quality of life of affected patients. We report a prospective study of 45 hirsute females attending a laser clinic. Of these, 15 patients completed a pair of modified dermatology life quality index (DLQI) questionnaires, immediately before and at varying intervals (up to 6 months) after laser treatment. The mean DLQI score before treatment was 12.8 (median = 9.0, SD = 8.5). The mean DLQI score at 1-2 months was 7.0 (median = 2.5, SD = 10.0, P = 0.06), at 2-4 months it was 9.2 (median = 10.0, SD = 10.0, P = 0.48) and at 4-6 months it was 11.5 (median = 10.5, SD = 8.0, P = 0.88). There was a major improvement in DLQI score at 1-2 months but longer-term benefit was not observed. In a separate questionnaire, hirsute females (n = 45) reported a high level of patient satisfaction (71.1%) and willingness to have further treatment (77.8%) despite the fact that 97.1% had unwanted hair back at pretreatment levels at 6 months.

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.

The long-term results of ruby laser depilation in a consecutive series of 346 patients

The goal of this study was to prospectively assess the long-term results of ruby laser depilation in 346 consecutive patients who underwent hair removal at 402 anatomical sites. The patients were treated using a ruby laser, with mean power ranging from 8.6 J to 15.7 J according to skin type. Results were assessed using two outcome measures-the percentage reduction in hair density and the hair-free interval. The median reduction in hair density was 55 percent (range, 0 to 100 percent) at a median time of 1 year after the last treatment session. The median hair-free interval was 8 weeks. Patients underwent a median number of four treatment sessions. Forty-three of the 346 patients were treated at more than one anatomical site. Of the sites treated, 75 percent reduction in hair density was achieved in 22 percent, 90 percent reduction was achieved in 2.2 percent, and complete depilation was achieved in only 0.7 percent. Darker colored hair was more effectively treated. Treatment efficacy was not affected by anatomical site, with the exception of the faces of male patients, which were found to be particularly resistant to treatment. There was a significant correlation between the number of treatments given and the outcome. The overall complication rate was 9.0 percent (36 of 402 sites) with respect to pigmentary changes and blistering, but varied according to Fitzpatrick skin type. The complication rate was highest in skin types V and VI (24.7 percent), with no complications in skin type I. Although a greater than 50 percent reduction in hair density was achieved in half of the 346 patients treated, complete depilation was achieved in only an extremely limited number of patients.

Leukotrichia developed following application of intense pulsed light for hair removal

BACKGROUND

Lasers and light sources are now used worldwide for permanent or prolonged hair removal. Patients now prefer lasers and light sources for hair removal because of their noninvasiveness and fewer reported side effects.

OBJECTIVE

To study and report on leukotrichia that developed following application of intense pulsed light (IPL).

METHODS

From February 9, 2001 to February 14, 2002 a total of 821 patients were treated for unwanted hair. The system used was a noncoherent IPL system, with a 650 nm flashlamp filter; the parameters used varied with different Fitzpatrick skin types. The patients were treated monthly, with the rate of hair loss, measured by hair counts, and possible side effects recorded.

RESULTS

Twenty-nine of 821 patients treated developed leukotrichia. Thirteen patients had no white or gray hairs before IPL therapy; the remaining 16 patients, who had few white hairs before treatment reported accelerated development of new white hairs starting after the first or second IPL therapy. Restoration of hair color occurred in 9 patients and the remaining 20 patients had no improvement or worsening of the condition within the next 2-6 months.

CONCLUSION

Temporary or permanent leukotrichia may develop following IPL and laser hair removal therapy. This finding may be explained by the difference in the thermal relaxation times of melanocytes and germinative cells. The light absorbed and the heat produced by melanin may be sufficient enough to destroy or impair the function of melanocytes but insufficient to damage the hair follicle cells.

Laser hair removal

The presence of unwanted hair continues to plague many individuals for whom traditional methods of hair removal remain unsatisfactory. Laser and flashlamp technology now offers the potential for rapid, safe, and effective treatment of unwanted hair. An ever-increasing number of published studies have confirmed the long-term efficacy of laser and flashlamp treatment. For the most part, however, the benefits of this technology have been limited to individuals with dark hair and relatively fair skin. The remaining challenge is to develop the means to eliminate light-colored hair as well as the capability to safely treat individuals with darker skin. The rapid pace of technological advancement as well as continued studies of hair follicle biology promise to improve this field over the years to come.

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.

Revisitando o Hirsutismo

O hirsutismo é definido como o crescimento excessivo de pêlos terminais na mulher, em áreas anatômicas características de distribuição masculina. Pode manifestar-se como queixa isolada, ou como parte de um quadro clínico mais florido, acompanhado de outros sinais de hiperandrogenismo, distúrbios menstruais e/ou infertilidade ou ainda alterações metabólicas relacionadas com hiperinsulinemia/resistência insulínica. O hirsutismo decorre da ação dos androgênios sobre a pele e depende de vários fatores correlacionados: níveis de androgênios e da SHBG e conseqüente relação hormônio livre/hormônio ligado, grau de sensibilidade cutânea aos androgênios, capacidade de conversão de androgênios em estrogênios e outras interconversões entre esteróides. Pode ser classificado em duas categorias: a) associado a uma hiperprodução glandular de androgênios pelos ovários e/ou suprarrenais ou b) decorrente de uma hiperutilização isolada dos androgênios circulantes pelo folículo pilo-sebáceo, correspondendo ao hirsutismo dito "idiopático". A causa mais freqüente do hirsutismo de origem glandular é a síndrome dos ovários policísticos. A hiperplasia adrenal congênita forma não clássica (HAC-NC) por deficiência da 21-hidroxilase é a causa mais freqüente de hirsutismo de origem adrenal, embora sua prevalência, entre mulheres hirsutas como um todo, seja relativamente baixa. Outras causas menos freqüentes são a síndrome de Cushing e os tumores virilizantes, ovarianos ou adrenais. Neste artigo são enfocados criticamente aspectos da avaliação diagnóstica do hirsutismo e os principios do tratamento com base em sua etiologia. São abordadas as indicações e limitações do uso de diferentes antiandrogênios e outros fármacos relacionados.

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.

Comparison of long-pulsed diode and long-pulsed alexandrite lasers for hair removal: a long-term clinical and histologic study

BACKGROUND

Unwanted facial and body hair is a common problem, generating a high level of interest for treatment innovations. Advances in laser technology over the past several years has led to the development and distribution of numerous red and infrared lasers and light sources to address this issue. Despite the impressive clinical results that have been reported with the use of individual laser hair removal systems, long-term comparative studies have been scarce.

OBJECTIVE

To compare the clinical and histologic efficacy, side effect profile, and long-term hair reduction of long-pulsed diode and long-pulsed alexandrite laser systems.

METHODS

Twenty women with Fitzpatrick skin types I-IV and dark terminal hair underwent three monthly laser-assisted hair removal sessions with a long-pulsed alexandrite laser (755 nm, 2-msec pulse, 10 mm spot) and a long-pulsed diode laser (800 nm, 12.5 msec or 25 msec, 9 mm spot). Axillary areas were randomly assigned to receive treatment using each laser system at either 25 J/cm2 or 40 J/cm2. Follow-up manual hair counts and photographs of each area were obtained at each of the three treatment visits and at 1, 3, and 6 months after the final laser session. Histologic specimens were obtained at baseline, immediately after the initial laser treatment, and 1 and 6 months after the third treatment session.

RESULTS

After each laser treatment, hair counts were successively reduced and few patients found it necessary to shave the sparsely regrown hair. Optimal clinical response was achieved 1 month after the second laser treatment, regardless of the laser system or fluence used. Six months after the third and final treatment, prolonged clinical hair reduction was observed with no significant differences between the laser systems and fluences used. Histologic tissue changes supported the clinical responses observed with evidence of initial follicular injury followed by slow follicular regeneration. Side effects, including treatment pain and vesiculation, were rare after treatment with either laser system, but were observed more frequently with the long-pulsed diode system at the higher fluence of 40 J/cm2.

CONCLUSION

Equivalent clinical and histologic responses were observed using a long-pulsed alexandrite and a long-pulsed diode laser for hair removal with minimal adverse sequelae. While long-term hair reduction can be obtained in most patients after a series of laser treatments, partial hair regrowth is typical within 6 months, suggesting the need for additional treatments to improve the rate of permanent hair removal.

Successful reduction in skin damage resulting from exposure to the normal-mode ruby laser in an animal model

Normal-mode ruby laser (NMRL) irradiation of skin has now become an acceptable method of producing depilation. However, side effects, which include superficial burning and changes in skin pigmentation, still occur and, although temporary, can be distressing to the patient. This paper reports a method by which the skin can be protected (or preconditioned) from damage during NMRL treatment by pre-heating to a lower, non-damaging level prior to irradiation. Using the black-haired mouse (C57B1/10) as an animal model, an appropriate 'preconditioning' temperature was established by exposing the mouse skin to a range of temperatures, taking biopsies and staining the skin immunohistochemically for heat shock protein 70 (HSP 70) expression within the keratinocyte cells. Increased HSP 70 expression is stimulated by exposure to environmental stressors such as heat, so it was hypothesised that its increased expression conveyed increased cellular protection. The appropriate temperature (45 degrees C for 15 min) allowed for the superficial skin cells to be protected (as assessed by maximal HSP 70 staining) but undamaged (as assessed by haematoxylin and eosin staining), leaving the target hair-producing cells unprotected. Eight mice (16 flanks) were then exposed to this preconditioning temperature (eight of the flanks being growing-hair sites and eight resting-hair sites) and 5 h later exposed to a laser fluence known to cause mild skin damage and depilation (6J/cm2). This exposure was to both the preconditioned and the adjacent non-preconditioned sites. A statistically significant reduction in skin damage (P <0.001), as measured by the time taken to heal and noted both clinically and histologically, was seen in the preconditioned sites in resting-hair regions but not in growing-hair regions. Depilation, established over an 8 week period, was successful in growing-hair regions within both preconditioned and non-preconditioned sites, but complete hair regrowth had occurred in preconditioned and non-preconditioned sites within resting-hair regions by 5 weeks. The latter finding was consistent with work already reported suggesting that NMRL-assisted depilation in this animal model is not successful for hairs in the telogen phase. Successful preconditioning of mouse skin prior to laser exposure appears to reduce NMRL-induced skin side effects. In addition, the technique does not appear to adversely affect successful depilation.

Lasers in dermatology--a critical update

Lasers are accepted for treating nevus of Ota, other pigmented lesions, hair removal, vascular lesions, leg veins, tattoos, and for skin resurfacing. These are photothermal treatments, in which certain skin "targets" are heated, followed by selective wound healing. Small pigmented targets such as the dermal melanocytes in nevus of Ota, are best treated with short (< 1 microsecond) laser pulses. Large targets, such as hair follicles, have long thermal relaxation times and are best treated with longer pulses. In general, the ideal pulse duration is about equal to the thermal relaxation time for pigmented targets. However, sometimes the actual target is not pigmented and is at some distance from a pigmented structure. For example the follicular stem cells, which are not pigmented, line the outer root sheath far away from the pigmented hair shaft. These cells appear to be an important target for permanent hair destruction. Pulses longer than the thermal relaxation time of the hair shaft allow heat conduction and better damage of follicular stem cells. Epidermal cooling works far better with pulses longer than about 10 ms, delivered through a cold medium (e.g., cold sapphire in contact with the skin). Thus, the combination of cooling and long near-infrared laser pulses allows safe and effective pigmented hair removal in all skin types. In contrast, epidermal protection from short pulses is best with dynamic pre-cooling (e.g., cryogen spray), for example during portwine stain treatment. A major challenge for the future of photothermal laser treatments is to develop ways of treating non-pigmented skin "targets". New uses for lasers are emerging. Diagnostic laser imaging and spectroscopy will soon emerge in dermatology. A near-infrared laser confocal microscope provides histology-like images of human skin. Imaging is painless and takes only a few minutes. Lesions including melanoma, basal cell and squamous cell carcinoma, microvascular and inflammatory lesions, dermatophytes, verrucae, etc, have distinct appearances. However, sensitivity and specificity of laser-based diagnostic imaging has not yet been compared with histopathology. Laser phototherapy is also emerging in dermatology. The 308 nm excimer laser has recently been shown to clear psoriasis faster than conventional phototherapy. Scalp psoriasis may soon be treated by fiber-optic delivery of this UV laser. The variety and utility of lasers in dermatology will probably continue to grow.