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Literature Review
A clinical review of hair removal using lasers and light source
Abstract
The tremendous demand for removal of unwanted hair has led to the development of a wide range of noninvasive, user-friendly laser and light source systems; however, despite considerable advances in this field, these devices still have the potential to cause injury when used improperly. It is important to follow precise treatment guidelines in order to attain optimal results. This article gives an overview of the currently available lasers and light sources. It focuses on the practical aspect of laser hair removal by discussing patient selection, safety precautions, techniques using the different systems, pre- and post-laser treatment care, proper treatment endpoints, expected outcome, and possible side-effects and complications.
... However, in various so-called permanent photoepilation studies also a temporary effect is reported [7,[17][18][19][20]. This effect is often independent of the degree of permanent hair reduction (as determined at least four months after the treatment). ...
... This effect is often independent of the degree of permanent hair reduction (as determined at least four months after the treatment). This temporary effect consists of a strong hair clearance 2-3 weeks after the treatment which is maintained for approximately 12 weeks, followed by partial or complete re-growth [18,21]. Apparently, most of the affected HFs go through a non-hair producing period, without losing the ability to develop a hair. ...
... Apparently, most of the affected HFs go through a non-hair producing period, without losing the ability to develop a hair. Histological studies reported in the literature suggest this temporary effect is a treatment-induced disturbance of the hair cycle, consistent with a catagen-like transition of the HF [8,18,21] without destruction of the stem cell region. For this catagen-inducing effect, it has been proposed that it is sufficient to damage the matrix cells of anagen HFs, coagulate blood vessels of the follicle papilla or partially destroy the ORS [22]. ...
We have recently shown that repeated low fluence photoepilation (LFP) with intense pulsed light (IPL) leads to effective hair removal, which is fully reversible. Contrary to permanent hair removal treatments, LFP does not induce severe damage to the hair follicle. The purpose of the current study is to investigate the impact of LFP on the structure and the physiology of the hair follicle.
Single pulses of IPL with a fluence of 9 J/cm(2) and duration of 15 milliseconds were applied to one lower leg of 12 female subjects, followed by taking a single biopsy per person, either immediately, or after 3 or 7 days. Additionally, we present a novel approach to examine the effects of LFP, in which ex vivo hairy human scalp skin was exposed to IPL pulses with the same parameters as above, followed by isolation and culturing of the hair follicles over several days. Samples were examined histologically and morphologically.
The majority of the cultured follicles that had been exposed to LFP treatment showed a marked treatment effect. The melanin containing part of the hair follicle bulb was the target and a catagen-like transformation was observed demonstrating that hair formation had ceased. The other follicles that had been exposed to LFP showed a less strong or no response. The skin biopsies also revealed that the melanin-rich region of the hair follicle bulb matrix was targeted; other parts of the follicle and the skin remained unaffected. Catagen/telogen hair follicles were visible with unusual melanin clumping, indicating this cycle phase was induced by the IPL treatment.
Low fluence photoepilation targets the pigmented matrix area of the anagen hair follicle bulb, causing a highly localized but mild trauma that interrupts the hair cycle, induces a catagen-like state and eventually leads to temporary loss of the hair.
... Hirsutism is mostly of benign origin, and the most common benign cause of hirsutism is polycystic ovarian syndrome (PCOS [1]). Ten to fifteen percent of hirsutism is considered idiopathic [2], commonly genetic or ethnic [3]. However, there is evidence that 40% of those with idiopathic hirsutism and a history of "regular" cycles actually are oligo or anovulatory [4]. ...
The aim of the study was to describe how women with hirsutism experience their relationship with health care. Data were collected by tape-recorded individual interviews, which were analyzed by means of qualitative content analysis. The results showed that the relationship with health care, from the perspective of patients with hirsutism, is suboptimal.
... 61,62 Light in the middle of this near-infrared (NIR) region (around 800 nm) can penetrate through skin and up to several centimeters into tissue, 17 (8) of PT applications in the tangential field of cosmetics. PT targeting of melanin, in the form of laser hair removal, 64,65 and PT targeting of hemoglobin, in the treatment of port-wine stains 66 and varicose veins, 67,68 and have been widely and successfully applied in the clinic for decades. These applications take advantage of the fact that in biological structures such as hair follicles and blood vessels, there is a locally higher concentration of melanin and hemoglobin, respectively, than is present within surrounding tissues. ...
Photothermal therapy (PTT) involves the application of normally benign light wavelengths in combination with efficient photothermal (PT) agents that convert the absorbed light to heat to ablate selected cancers. The major challenge in PTT is the ability to confine heating and thus direct cellular death to precisely where PT agents are located. The dominant strategy in the field has been to create large libraries of PT agents with increased absorption capabilities and to enhance their delivery and accumulation to achieve sufficiently high concentrations in the tissue targets of interest. While the challenge of material confinement is important for achieving "heat and lethality confinement," this review article suggests another key prospective strategy to make this goal a reality. In this approach, equal emphasis is placed on selecting parameters of light exposure, including wavelength, duration, power density, and total power supplied, based on the intrinsic properties and geometry of tissue targets that influence heat dissipation, to truly achieve heat confinement. This review highlights significant milestones researchers have achieved, as well as examples that suggest future research directions, in this promising technique, as it becomes more relevant in clinical cancer therapy and other noncancer applications. © 2017 Society of Photo-Optical Instrumentation Engineers (SPIE).
... The effectiveness of different optical depilation devices varies considerably due to the different wavelengths, energy levels, pulse durations, and biological variables such as anatomical location, epidermal pigmentation, duration of the hair follicle cycle, and androgen status. 11,17 The target chromophores of photoepilation are the melanin-rich hair shafts and bulbs. However, competing chromophores exist, e.g., epidermal melanin and other lightabsorbing components, such as Hb in blood vessels. ...
BACKGROUND Recently, intense pulsed light (IPL) sources have been shown to provide long-term hair removal.OBJECTIVE This study examined the photoepilatory effects of different wavelengths and pulse width application in the same device and compared their efficiencies in Asian skin.METHODS Twenty-eight Korean women were treated using HR (600–950 nm filter) and 27 using HR-D (645–950 nm filter) in the axillar area. Four treatments were carried out at intervals of 4 to 6 weeks; follow-ups were conducted 8 months after the last treatment. Mean energy settings were 14.9±2.0 J/cm2 for HR and 17.1±0.6 J/cm2 for HR-D. Longer pulse widths were applied in case of HR-D treatment. Hair counts and photographic evaluation of skin sites were made at baseline and at the last follow-up. Final overall evaluations were performed by patients and clinicians.RESULTS Average clearances of 52.8% and 83.4% were achieved by HR and HR-D, respectively. No significant adverse effects were reported after HR-D treatment. One case each of hypopigmentation and hyperpigmentation was reported for HR.CONCLUSION An IPL source by removing 45 nm of the emitted spectra and applying longer pulse width was found to provide a safer and more effective means of photoepilation in Asian patients.
The pulsed dye laser has revolutionized the treatment of vascular anomalies. More recently, the multiplex laser, a combination of pulsed dye and Nd:YAG, has been shown to be beneficial for recalcitrant port wine stains and other conditions. In addition to their use in treating port wine stains, lasers have also an important role in treating a number of childhood pigmentary disorders. These are primarily congenital naevi such as café‐au‐lait macules, naevus of Ito and some blue lesions. Laser treatment is based on selective thermal destruction or damage to a targeted chromophore located in the skin, either that of blood, melanin or tissue water. Lasers have been shown to successfully treat vascular and pigmented lesions and also remove unwanted hair. They can also be used to remove verrucous lesions such as angiofibromas and epidermal naevi through vaporization.
Existing remedies for controlling pseudofolliculitis barbae (PFB) are sometimes helpful; however the positive effects are often short lived. The only definitive cure for PFB is permanent removal of the hair follicle.
Our aim was to compare the efficacy of the Alexandrite laser with the intense pulsed light system in the treatment of PFB and to follow up the recurrence.
Twenty male patients seeking laser hair removal for the treatment of PFB were enrolled in this study. One half of the face was treated with the long-pulse Alexandrite laser and the other half was treated with the IPL system randomly. The treatment outcome and any complications were observed and followed up for one year.
All patients exhibited a statistically significant decrease in the numbers of papules. Our results showed that the Alexandrite-treated side needed seven sessions to reach about 80% improvement, while the IPL-treated side needed 10-12 sessions to reach about 50% improvement. During the one year follow up period, the Alexandrite-treated side showed recurrence in very minimal areas, while the IPL-treated side showed recurrence in bigger areas.
Our results showed that both systems might improve PFB but Alexandrite laser was more effective at reducing PFB than IPL.
Polycystic ovary syndrome is a common endocrinological problem in women of reproductive age. Polycystic ovary syndrome is a heterogenous disorder and patients may attend different clinics depending on the main complaint. The exact pathophysiology of polycystic ovary syndrome remains obscure, although there have been insights that have thrown light on this condition. Consensus on the definition of the syndrome has only been recently achieved. The management of polycystic ovary syndrome poses a challenge to the physician as responses to the different treatment regimes have proved to be inconsistent. Diet and lifestyle advice, restoration of menstrual cycle regularity, treatment of hyperandrogenism, treatment of infertility and prevention of long-term consequences form the basis of polycystic ovary syndrome management. This review aims to provide the reader with the latest evidence in the treatment of polycystic ovary syndrome, as well as focus on some of the controversies surrounding its management.
Several adverse effects of depilatory laser may now be commonly expected in relation to skin type and anatomic location. We report and analyse unusual events in patients undergoing laser-assisted axillary hair removal, including hyperhidrosis, bromhidrosis and leukotrichia.
The aim of this study was to examine a large patient population, assess the frequency of these adverse effects, and establish a correlation with different hair-removal laser protocols.
A retrospective case-control study of patients undergoing laser-assisted axillary hair removal was conducted to determine the incidence of these adverse effects in relation to skin type and types of laser used.
Hyperhidrosis, bromhidrosis and leukotrichia were seen in 11, 4, and 2% of patients respectively. Hyperhidrosis was significantly less frequent in patients with skin types III and IV than in those with skin type II or V. Combined diode and alexandrite laser sessions were associated with a significantly higher incidence of hyperhidrosis compared to diode or alexandrite sessions alone. Regarding bromhidrosis and leukotrichia, no significant correlation with age, skin type or laser settings was revealed by the statistical analysis.
Hyperhidrosis, bromhidrosis and leukotrichia are likely new adverse effects of laser-assisted axillary hair removal.
Many women suffer from excessive hair growth, often in combination with polycystic ovarian syndrome (PCOS). It is unclear how hirsutism influences such women's experiences of their bodies. Our aim is to describe and interpret women's experiences of their bodies when living with hirsutism. Interviews were conducted with 10 women with hirsutism. We used a qualitative latent content analysis. Four closely intertwined themes were disclosed: the body was experienced as a yoke, a freak, a disgrace, and as a prison. Hirsutism deeply affects women's experiences of their bodies in a negative way.
This study demonstrates the ability to treat successfully alopecia areata-like hair loss in both mouse and rat models using topical immunotherapy with diphencyprone.
Conventional treatment options for hypertrichosis and hirsutism are tedious and time consuming. Laser hair removal offers an efficient way to permanently reduce excessive hair growth. Hair is damaged using the principle of selective photothermolysis with wavelengths of light well absorbed by follicular melanin and pulse durations that selectively thermally damage the target without damaging surrounding tissue. Patients with dark hair and light skin are ideal candidates. Multiple treatments (3 to 6) performed every 6-8 weeks are necessary to achieve a permanent reduction of hair growth. As the field develops, a better sense of the effectiveness of laser hair removal will evolve and reasonable expectations will be determined.
Several laser systems are currently used for epilation. However, the optimal parameters and treatment protocols remain largely unknown. In this study, the histopathological changes in the hair follicles after long pulsed alexandrite laser irradiation are discussed and the clinical application of irradiation energy at the time of treatment is described. The laser used in this study is equipped with a computer controlled cooling device. A histopathological study was performed to compare the differences in the degree of degeneration in the epidermis and follicles treated with and without the cooling device. In comparison with normal hair papilla, in the laser irradiated skin, injury of melanin containing cells and hair shafts and external root-sheaths in the periphery were observed, while the epidermis was completely protected by the cooling device. The condition of the hair papilla of the tissue irradiated at a fluence of 25 J/cm2 with a spot diameter of 15 mm and 20 J/cm2, with a spot diameter of 18 mm were investigated thoroughly. Swollen papilla and selective destruction of the site where melanocytes were present were observed. The results of this study strongly indicate the efficacy of a long-pulsed alexandrite laser equipped with a computer controlled cooling device for clinical depilation.
The Candela alexandrite and the Coherent diode laser systems come equipped with built-in skin cooling systems that are designed to both protect the epidermis, allowing higher fluences, and to alleviate discomfort. Nevertheless, pain can be a significant problem especially with treatment of larger areas. Scatter of the laser beam is reportedly affected by the spot size. It is claimed that larger spot sizes are more effective at identical fluences.
This study evaluated the effectiveness of a topical 5% lidocaine cream (ELA-Max) to control pain and compared pain levels at identical fluences between the 8 mm and 12 mm spot size of the alexandrite laser and between the alexandrite and diode laser with its 9 mm spot size.
The study was conducted in the axillae of 12 patients. Each axilla was divided in half for side-by-side comparison. Half of the right axilla was treated with the alexandrite 8 mm and the other half with the 12 mm spot size at identical fluences. The left axilla was treated at the maximum tolerated fluences with the alexandrite 12 mm spot size and the diode 9 mm spot size.
At identical fluences and other parameters, there was significantly more pain with the alexandrite 12 mm spot size than with the alexandrite 8 mm spot size, both with or without topical anesthesia. The alexandrite laser was significantly less painful than the diode laser both with and without topical anesthetic. The difference was most noticeable between the alexandrite 8 mm spot size and the diode 9 mm spot size. Topical 5% lidocaine anesthesia was effective in reducing pain, though not completely, for both the alexandrite and the diode lasers.
Topical 5% lidocaine cream is a simple and effective method for reducing patient discomfort during laser hair removal procedures, even when a skin cooling device is being used. A larger spot size causes more pain than a smaller spot size at identical fluences. The 800 nm diode laser causes greater discomfort than the 755 nm alexandrite laser.
Numerous lasers are currently available for hair removal, yet there are still few studies that have examined the role of fluence, light dose, hair color, and treatment number in laser hair reduction.
To demonstrate the efficacy and safety of a scanning 800 nm diode laser for hair reduction.
An 800 nm scanning diode laser was used to deliver 24, 38, or 48 J/cm2 to a 3 cm x 3 cm area of skin located on the back, groin/bikini area, or thigh in 36 adult patients with varying shades of brown or black hair. Patients received one to four treatments during the course of the study. Hair loss was evaluated at both 30 and 90 days after final treatment. Biopsies were obtained from 20 consenting patients.
Significant fluence-dependent hair reduction was demonstrated between treatment and control groups. At 48 J/cm2, the highest dose, a mean hair reduction of 43% was achieved 30 days after the final treatment, and 34% was achieved 90 days after the final treatment. Darker hairs were more effectively treated than lighter hairs.
Hair reduction can be safely and effectively achieved using a scanning 800 nm diode laser.
The goal of laser or flashlamp photoepilation is to produce long-term, cosmetically significant hair removal. We document the long-term efficacy achieved with an intense pulsed light source for photoepilation.
Prospective study comparing long-term results of single vs multiple treatments, and effects of anatomic site and skin type on efficacy of photoepilation with a device emitting broad-spectrum, noncoherent (nonlaser) radiation from 550- to 1200-nm wavelengths, in macropulses divided into 2 to 5 minipulses.
Private dermatology practice.
Thirty-four patients (8 men, 26 women) with hirsutism.
Parameters for the study were wavelength of 615 to 695 nm, pulse duration of 2.6 to 3.3 milliseconds, fluence of 34 to 42 J/cm(2), 10 x 45-mm exposure field, and application of 1 degrees C cooling gel.
Hair removal efficiency, calculated as percentage ratio of the number of hairs present compared with baseline counts, and patient satisfaction questionnaire completed at last follow-up.
The mean hair removal efficiency achieved was 76% after a mean of 3.7 treatments. More than 94% of the sites reached mean hair removal efficiency values greater than 50%. Hair removal efficiency was not significantly related to skin type, hair color, anatomic site, or number of treatments. Side effects were mild and reversible and occurred in a minority of patients (hyperpigmentation in 3 and superficial crusting in 2).
Our data document the long-term clinical efficacy of intense pulsed light source-induced hair removal in light and dark skin phenotypes. Maximal photoepilation was achieved from the initial 1 to 3 treatments; only a small added benefit was seen after more treatments.
This study aimed to evaluate the safety and efficacy of a 3.5 ms Nd:YAG laser for the removal of hair in subjects with Fitzpatrick skin types I-IV. Thanks to a pulse shorter than the hair Thermal Relaxation time (TRT), photothermolysis was thus achieved.
This study assessed the percentage of hair reduction at 1 month and at 3 months after a single Nd:YAG laser treatment (Athos; Quantel Médical, France); 3.5 ms pulse, single shot to 3 Hz, a maximum fluence of 80 J/cm2, 4 mm spot, no cooling system, no anaesthesia. The treatment sites consisted of three adjacent squares (optimum fluence, no treatment, -20% optimum fluence). Computerized hair counting was realized on digital pictures. The phototype, pain, side effects and patient's satisfaction were noted. Biopsies were performed 15 min after treatment. The enrolment consisted of 17 women, 22-60 years old, phototypes I-IV, with a follow-up at 1 month and 3 months of 25 sites.
Counting at 1 month and at 3 months revealed a significant hair reduction compared with the control sites: 60% at 1 month (P < 0.001) and 24% at 3 months (P < 0.05) for optimal fluence (25-80 J/cm2), compared with 31% and 0% on the control sites; values similar to those published for Nd:YAG or diode lasers. There were no adverse effects at all. Biopsies showed lesions from necrosis coagulation of the root sheaths and hair disruption to isolated apoptotic cells in the outer root sheath, depending on the fluence applied.
Results from this study show that the Athos Nd:YAG is efficient and safe for removing pigmented hair in phototypes I-IV.
Pulses of high intensity laser light, when focused into transparent materials, may produce localized electron-ion plasmas through optical breakdown. By simultaneously incorporating the resulting volume of vaporized material within the focal volume of a high intensity ultrasound source, the photodisruption (1.05 microm wavelength) void served as a nucleation site for ultrasonic cavitation. Dilute suspensions of canine erythrocytes in phosphate buffered saline were exposed in a flow-through exposure chamber and the percentage of lysed cells was used as a measure of the biologically effective cavitation activity produced in the chamber. Brief (about 30 micros) acoustic emissions were detected from the photodisruption alone (indicating laser nucleation of bubbles), but the cell lysis produced was undetectable against the background. However, combined exposure greatly increased both the duration of the acoustic emissions (up to 1.5 ms) and the amount of cell lysis above an ultrasonic pressure amplitude threshold of about 4.3 MPa at 2.5 MHz. The amount of cell lysis (sometimes approaching 100%) increased with increasing ultrasonic intensity, laser pulse energy and laser PRF. Addition of 5% serum albumin enhanced the effect, apparently by stabilizing bubbles and nuclei. Photodisruptive laser nucleation of ultrasonic cavitation can provide controlled and synergistic enhancement of bioeffects.
The majority of lasers used for hair removal target melanin as the chromophore. In contrast with other cutaneous applications of lasers, lasers used for hair removal must generate a limited, controlled degree of thermal damage to permanently remove hairs.
To remove excess back hair from two male patients, one with a history of multiple nevi, and prior biopsies showing features of dysplastic nevi, and the other with large nevi greater than 6 mm in diameter and a family history of malignant melanoma.
Both patients received monthly treatments with an 810 nm, pulsed, high-power diode laser using a fluence of 20 J/cm2 and 25-30 J/cm2, respectively, and a pulse duration of 30 ms.
Both patients presented 1 month after their last treatment with changing nevi within the treatment areas. Neither patient had clinical inflammation or other alterations suggestive of change in the nevi related to treatment. Thus, the nevi were excised with no mention of the previous laser treatment. The histologic features in all nevi were similar. There was subepidermal blister formation with elongation and disruption of nevus cells. There was homogenization of the collagen within the papillary dermis in all lesions. Only small foci of nevus cells could be identified in the dermis in some of the biopsy specimens. In these biopsy specimens, the dermal stromal matrix homogenization extended into the reticular dermis.
Laser targeting of nevus cells and surrounding structures may produce clinically atypical nevi in areas previously treated for hair removal. This should be kept in mind, especially in patients with a history of dysplastic nevi or with a personal or family history of malignant melanoma.
Thermal effects of laser radiation at cell level play very important role in cell functioning and in many laser applications. The aim of this study was to evaluate a new method of photothermal imaging (PTI) for monitoring short-time nano-scale thermal effects in individual living cells.
PTI is based on the irradiation of a cell with a short laser pump pulse (8 nanoseconds, 532 nm) and on registration of the laser-induced local thermal effects using time-resolved phase-contrast imaging with a pulsed probe laser.
PT images of lymphocytes, lympholeukemia cells in vitro were obtained at different laser energies. PTI in time-resolved mode allowed visualizing the structures with size less than diffraction limit (90-nm liposomes). The photodamage process was visualized for a single human leukocyte in suspension.
PTI in non-invasive mode offered better contrast of living cell image than conventional optical phase-contrast microscopy. The data obtained showed that PTI is in perspective for studies of live non-fluorescent cells.
Laser and other light sources have been used to treat vascular and pigmented skin lesions and to remove tattoos and unwanted hair, with varying degrees of success and various side effects. It has not yet been reported that hair growth can occur as a side effect of such treatments. In this paper two cases are presented, one port wine stain and one tattoo, that were each treated several times with an intense pulsed light source (IPLS) for removal. Terminal hair, not present before treatment, partially developed in treated areas of both lesions. Local inflammatory reactions are believed to trigger such outcomes.
Hypertrichosis is the term used for the growth of hair on any part of the body in excess of the amount usually present in persons of the same age, race, and sex, excluding androgen-induced hair growth. In its generalized and circumscribed forms, hypertrichosis may either be an isolated finding, or be associated with other abnormalities. Therefore, accurate classification of hypertrichosis is mandatory. Excessive hair may cause cosmetic embarrassment, resulting in a significant emotional burden, particularly if extensive. Treatment options are limited, and the results of therapy not always satisfactory. Patients should, therefore, be adequately advised of the available treatment modalities for temporary or permanent hair removal. No single method of hair removal is appropriate for all body locations or patients, and the one adopted will depend on the character, area, and amount of hair growth, as well as on the age of the patient, and their personal preference. The currently available treatment methods include cosmetic procedures (bleaching, trimming, shaving, plucking, waxing, chemical depilatories, and electrosurgical epilation), and hair removal using light sources and lasers. Laser-assisted hair removal is the most efficient method of long-term hair removal currently available. The lack of comparative data make it difficult to choose the most effective system, however, although the color contrast between epidermis and the hair shaft will determine the type of laser to favor. A novel treatment for slowing excessive hair growth is topical eflornithine, an inhibitor of the enzyme ornithine decarboxylase present in hair follicles that is important in hair growth. In general, treatment of hypertrichosis is more satisfactory for patients with localized involvement, than for those with generalized hypertrichosis.
This study was performed in order to evaluate patient satisfaction with epilation using an intense pulsed light source.
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.
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.
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.
Hirsutism is a common disorder, often resulting from conditions that are not life-threatening. It may signal more serious clinical pathology, and clinical evaluation should differentiate benign causes from tumors or other conditions such as polycystic ovary syndrome, late-onset adrenal hyperplasia, and Cushing's syndrome. Laboratory testing should be based on the patient's history and physical findings, but screening for levels of serum testosterone and 17alpha-hydroxyprogesterone is sufficient in most cases. Women with irregular menses and hirsutism should be screened for thyroid dysfunction and prolactin disorders. Pharmacologic and/or nonpharmacologic treatments may be used. Advances in laser hair removal methods and topical hair growth retardants offer new options. The use of insulin-sensitizing agents may be useful in women with polycystic ovary syndrome.
Approximately 10% of women of childbearing age are hirsute, which is defined as the presence of coarse terminal hairs in androgen-dependent areas on the face and body. It not only is a source of psychological discomfort but also may be a sign of an underlying medical condition. This article reviews the pathophysiology, diagnosis, evaluation, and treatment of hirsutism.
Hirsutism is a common disorder in women of reproductive age, and androgen disturbances may aggravate the condition. Limited evidence exists regarding efficacy of hair removal in this specific population and no data are available for patients with verified normal testosterone levels.
To compare efficacy and safety of intense pulsed light (IPL) vs. long-pulsed diode laser (LPDL) in a well-defined group of hirsute women with normal testosterone levels.
Thirty-one hirsute women received six allocated split-face treatments with IPL (525-1200 nm; Palomar Starlux IPL system) and LPDL (810 nm; Asclepion MeDioStar XT diode laser). Testosterone levels were measured three times during the study period. Patients with intrinsically normal or medically normalized testosterone levels throughout the study were included in efficacy assessments (n = 23). Endpoints were reduction in hair counts assessed by blinded photoevaluations at baseline and 1, 3 and 6 months after final treatment, patient-evaluated reduction in hairiness, patient satisfaction, treatment-related pain and adverse effects.
IPL and LPDL reduced hair counts significantly, with median reductions from baseline of 77%, 53% and 40% for IPL and 68%, 60% and 34% for LDPL at 1, 3 and 6 months, respectively. At 6 months follow-up, there was no significant difference between treatments in terms of hair reduction (P = 0·427), patient assessment of hairiness (P = 0·250) and patient satisfaction (P = 0·125). Pain scores were consistently higher for IPL [median 6, interquartile range (IQR) 4-7] than LPDL (median 3, IQR 2-5) (P < 0·001).
Hirsute women with normal or medically normalized testosterone levels responded equally well to IPL and LPDL treatments of facial hairiness, but the efficacy declined over 6 months.
Laser and IPL treatments for hair removal depend on the presence of melanin in the hair shaft. The ideal patient for laser
hair removal has light skin with black, coarse hair. There is substantial evidence for laser and photoepilation with a total
of 43 identified controlled trials in the beginning of 2009. Laser treatment and photoepilation are superior to conventional
treatments such as shaving, waxing, and electrolysis. Repetitive treatments improve the efficacy from laser and photoepilation.
A short-term hair removal efficacy up to 6 months after treatment is well-documented for ruby, alexandrite, diode, and Nd:YAG
lasers, as well as intense pulsed light. Evidence exists for a long-term hair removal efficacy beyond 6 months after repetitive
treatments with alexandrite, diode, and long-pulsed Nd:YAG lasers. White, grey, and red hairs do not respond sufficiently
to standard treatments but eflornithine, topical melanin, and photodynamic therapy may offer new treatment options for these
difficult-to-treat hair types although substantial evidence today is lacking. Today, there is no evidence for complete and
persistent hair removal. Patients should be preoperatively informed of the expected treatment outcome from laser and IPL hair
removal procedures in order to gain realistic expectations. Consumer-based home devices are evolving.
One underreported, rare side effect of laser hair removal, is paradoxical hypertrichosis. It is largely unknown what the long-term outcomes are of patients who develop this complication. We report a 21-year-old, Fitzpatrick II, male patient, who had patchy areas of dark hair affecting various body areas. An Alexandrite 755 nm laser was used to address the desired areas at energies between 20–22 J/cm² at 10–12 week intervals over a course of 7 treatments. After 3 treatments, the patient noted a significant increase in the density and length of hairs involving the back, shoulders, neck and upper arms. The patient was followed on a bi-annual basis, without further epilatory intervention. After 10 years, the areas of paradoxical hair growth were sparser compared to immediate post-treatment but remained denser compared to pre-treatment. This case illustrates improvement in the condition over time without intervention. Further studies are needed to determine the etiopathogenesis of this phenomenon.
Although the loss of scalp hair is distressing and many medical treatments focus on its restoration, the removal of body hair has been adopted since ancient times. Beauty standards, which r eflect the culture of each society, have been presenting the depilated body as absolutely desirable. Through the ages various methods of hair removal have been used depending on the requirements of the individuals. In recent years, Laser and Intense Pulse Light devices have been considered as the most promising solution for excess hair growth, without excluding the efficacy of other methods to induce satisfactory epilatory results. The enzyme-based hair removal method has received little recognition even though experimental and clinical data support its efficacy to provide long term or even permanent epilation. The present review presents these data and examines the likelihood of considering the aforementioned method as ideal.
Der Erfolg von Laser- und IPL-(″intense pulsed light″-)Behandlungen zur Haarentfernung ist von der vorhandenen Melaninmenge im Haarschaft abhängig. Der ideale Patient für die lasergestützte Haarentfernung hat helle Haut mit schwarzen, dicken Haaren. Die Beweislage für die Wirksamkeit der Laser- und Photoepilation ist sehr umfangreich; Anfang 2009 lagen 43 kontrollierte Studien dazu vor. Laserbehandlung und Photoepilation sind den herkömmlichen Methoden wie Rasur, Wachsbehandlung und Elektrolyse überlegen. Wiederholungsbehandlungen verbessern den Wirkungsgrad der Laser- und Photoepilation. Für den Rubin-, Alexandrit- und Diodenlaser sowie den Neodymium:Yttrium-Aluminium-Granat-Laser (Nd:YAG-Laser) und für IPL-Geräte konnte mehrfach eine kurzfristige Wirksamkeit bei der Haarentfernung für einen Zeitraum von bis zu 6 Monaten nachgewiesen werden. Des Weiteren liegen Beweise für eine langfristige Wirksamkeit von Wiederholungsbehandlungen mit Alexandrit- und Diodenlasern sowie langgepulsten Nd:YAG-Lasern vor, die länger als 6 Monate anhielt. Weiße, graue und rote Haare sprechen nicht ausreichend auf Standardbehandlungen an. Eflornithin, topisches Melanin und die photodynamische Therapie können jedoch neue Behandlungsoptionen für diese schwierig zu entfernenden Haartypen darstellen, obwohl es bisher noch an maßgeblicher Evidenz dazu mangelt. Zum jetzigen Zeitpunkt gibt es keine Evidenz für eine vollständige und dauerhafte Haarentfernung. Die Patienten sollten vor der Behandlung mit Laser und IPL über das zu erwartende Ergebnis aufgeklärt werden, um eine realistische Erwartungshaltung zu ermöglichen. Geräte für den Hausgebrauch, die von den Patienten selbst bedient werden können, sind auf dem Vormarsch.
Haarwuchsprobleme sind häufig, Betroffene zeigen einen oft hohen Leidensdruck, und die Behandlungsmöglichkeiten sind beschränkt. Vor diesem Hintergrund hat die Bewältigung von Haarproblemen auf den Ebenen des Informationsverhaltens, der Problemlösekompetenz und der medizinischen Therapie zu erfolgen.
Unerwünschter Haarwuchs ist ein häufiges Problem in der dermatologischen Praxis. Laser- und Lichtsysteme werden seit Jahren zur Entfernung von unerwünschtem Haarwuchs eingesetzt und erfreuen sich ständig wachsender Popularität. Einer zunehmenden Fülle von Geräten und äußerst optimistischen Einschätzungen der Hersteller stehen wachsende Nachfrage und Ansprüche der interessierten Patienten gegenüber. Sowohl für Anwender als auch für Patienten stellt sich die Frage der Effektivität der jeweiligen Geräte. In einer retrospektiven Auswertung der Daten von mehr als 500 Behandlungen an über 300 Patienten sind wir der Frage nach der Wirksamkeit der Behandlung mit einem 800-nm-Diodenlaser (LightSheer) nachgegangen und berichten über Erfahrungen in der Anwendungspraxis.
As governed by cultural norms, excess hair, especially on the face, is a very common and often embarrassing issue for many patients. In the past century, unwanted hair was traditionally treated with many different modalities that were slow, tedious, painful, impractical, and resulted in poor long-term efficacy. Consequently, there has been a public demand for novel, rapid, reliable, safe, and affordable hair-removal techniques. In the last couple of decades, a number of laser and lightbased technologies have been developed for hair removal that specifically target hair follicles and allow for the potential treatment of large areas with long-lasting results. The quest for truly permanent photoepilation and the ability to treat white hairs and darker-skinned patients are the current goals for improvement in this evolving field.
Laser (Ruby, Nd Yag, Alexandrite, Diode) or intense pulse light are the different light-/Laser-based systems used for hair removal; each have its advantages and disadvantages. Laser parameters vary with area, type of hair, and the machine used. Full knowledge about the device and cooling system is important to improve the treatment performance.
Lasers for hair removal are a fast-growing area in cosmetic dermatology.
Selective photothermolysis allows for targeting of specific chromophores while minimizing cutaneous damage.
Treatment of individuals should be individualized based on anatomical area, skin and hair color, by varying the wavelength, fluence, pulse duration, spot size, and cooling technique of the laser.
Nearly a quarter of a century has passed since the theory of 'selective photothermolysis' was postulated by Anderson and Parrish. This has since been applied to the treatment of cutaneous vascular malformations, to pigmentary disorders, tattoos and unwanted hair. Lasers have also become more sophisticated in terms cooling technology and the availability of higher fluences, bigger spot sizes and variable pulse durations Skin resurfacing, usually but not exclusively of wrinkles and acne scarring, has evolved from an early emphasis on ablation alone to recognition of the advantages of underlying thermal damage and eventually to attempts at non-ablative (including 'fractional') wounding of the dermis Photodynamic therapy is effective in treating some superficial non melanoma skin cancer and its precursors and is under investigation in other dermatoses
The first all-inclusive text on the pitfalls, complications and controversies surrounding the use of lasers in dermatology and aesthetic medicine. Each chapter starts off by highlighting the key points and essential concepts, followed by a review of the associated pearls and problems. Provides the reader with tips on how to improve the safe and effective use of lasers. Images focus on the pearls and problems. Laser Dermatology: Pearls and Problems is different from other laser dermatology books. Each of the five chapters begins by highlighting key points and essential concepts, then focuses on the pearls and problems for each area - based on the author's vast experience in the field of laser dermatology. Dr. Goldberg addresses: Vascular Lasers. Laser Hair Removal. Pigmented Lesions, Tattoos, and Disorders of Hypopigmentation. Ablative Lasers and Devices. Non-Ablative Photorejuvenation and Skin Remodeling. Dr. Goldberg goes beyond the standard "before and after" approach to use actual images to demonstrate the pearls and pitfalls discussed in the text.
Background: Unwanted facial and body hair can cause severe cosmetic, social and psychological problems. Light assisted hair removal, using lasers and intense pulse light sources, because of their long term results and safety, has emerged as a promising method in hair removal. Objective: To determine the efficacy and safety of intense pulse light (IPL) in the treatment of idiopathic facial hirsutism. Setting: Dermatology Department Unit-II, Mayo Hospital, Lahore. Duration of Study: Six months since 15 th October, 2009. Study Design: Experimental analytical. Patients and Methods: It is an ongoing study of 50 patients and so far 46 with idiopathic facial hirsutism have been enrolled. All selected variables were recorded on a printed Proforma. The starting fluence and pulse duration were determined according to skin type. They were treated at 4 – 6 weeks interval for six treatments. Efficacy and safety was determined at the end of treatment. Efficacy was graded according to a 4-point scale from excellent to poor. Results: Twenty eight percent patients in group A (completed 5 sessions), 11% patients in group B (completed 4 sessions) and 7% patients in group C (completed 3 sessions) showed excellent response i.e. > 75% hair reduction whereas 43% in group A, 56% in group B and 14% in group C showed a good response i.e. 50 – 75% hair reduction. Persistent erythema was observed in 16%, folliculitis in 13% and hyperpigmentation in 10% of the patients. Conclusion: IPL is a safe and effective for treatment of idiopathic hirsutism.
Excess or unwanted hair is a common problem affecting both genders. Over time, this problem has been dealt with in various
ways, including plucking, threading, shaving, waxing, and electrolysis. Although effective for short-term control of hair
growth, most of these methods are associated with significant pain and prolonged treatment times, making them fairly impractical
for larger areas such as the human trunk.
The use of the long-pulsed Nd:YAG laser for hair removal is currently being studied. It may offer advantages over some of the preexisting laser hair removal systems, especially in more darkly pigmented patients. Histologic examinations of biopsies taken after treatment demonstrate focal heat-induced damage to the hair follicle. Many laser systems have been successfully utilized for hair removal, including the Q-switched Nd:YAG, the diode, the long-pulsed ruby and alexandrite lasers. [1] However, some these systems can be poorly tolerated in more darkly pigmented patients due to side effects of erythema, blistering, and post-inflammatory hyper or hypo-pigmentation. The wavelength of the Nd:YAG laser provides certain advantages in targeting hair follicles over the other systems. The longer wavelength leads to deeper penetration, enabling the energy of the laser to reach the hair bulbs and/or bulge located in the lower dermis. These follicular structures are the desired target since they are believed to be critical in hair regrowth. [2] The wavelength of the Nd:YAG also induces less energy absorption by other cutaneous structures, leading to less collateral damage and more efficient penetration. The decreased epidermal absorption accounts for the reduction in side effects seen with the Nd:YAG laser in darker skinned individuals. [3] Theoretically, the pulse duration of a hair removal laser should be shorter than the thermal relaxation time (TRT) of the hair follicle but longer than the TRT of the epidermis in order to maximize follicular damage while minimizing epidermal damage. This means that the ideal pulse width should be between 10-60ms. However, the Nd:YAG systems that have traditionally been used employ a Q-switched technology (either with or without the adjunct of a topical carbon-based solution to serve as a chromophore). The exact mechanism by which the Q-switched systems selectively destroy hair follicles is not well understood but probably relates to a photoacoustic event. [3] It is recognized that some patients having tattoo removal will notice coincidental permanent hair reduction in the treated areas. More recently, long-pulsed Nd:YAG lasers have been developed, combining the wavelength advantage of the Nd:YAG and the longer pulse duration advantage of the other long-pulsed systems. These include the Lyra by Laserscope and the CoolGlide by Altus. Only recently placed on the market, little clinical data on these new lasers is available at this time. A study of the Lyra using fluences of 100 J/cm 2 for facial hair and 130 J/cm 2 for non-facial hair and pulse duration of 30 msec showed successful reduction of hair growth at 3 months after a single treatment. [4] A study of the CoolGlide laser is also currently underway, using fluences of 50-60 J/cm 2 and pulse widths of 15-30 msec. [5] Three month preliminary results show a 24-32% reduction in hair growth in treated sites compared with 8% in the control sites and minimal side effects. We have treated 20 patients with the Lyra, several of whom had with Fitzpatrick type IV and V skin.
Irradiation of 15 nm gold particles with nano- and picosecond laser pulses can create locally temperatures beyond the critical point of water. Due to the short heating times the temperature is localised to the vicinity of the particles. Under irradiation with nano- and picosecond pulses an inactivation of the enzymes alkaline phosphatase and chymotrypsin which were bound to the surface of the particles was observed. As expected by strong temperature gradient caused by the short irradiation time the protein inactivation is localized within a few tens of nanometers when picosecond pulses were used. This was shown by irradiating gold protein conjugates in which the protein was bound via two anitbodies to the particle.
Today, most do not go a day without practicing or hearing about new hair removal methods. However, little is discussed about the history of hair removal and the development of most hair removal methods since the period of cavemen. Avoiding decapitation and fitting in with society are two of many reasons for the development of this now normative practice. Knowledge of the hair growth cycle is vital in understanding the efficacy of various hair removal methods as well as the difference between epilation and depilation. While laser hair removal (LHR) is one of the most common cosmetic procedures practiced in the world, according to the FDA, the only current permanent form of hair removal is electrolysis. These two methods as well as various other ones are discussed in this article. Further developments are being made every day to better treat the removal of blonde and white hair as well as to diminish the pain of hair removal. With these developments, dermatologists will better understand the advancement of hair removal methods and the reasons why patients may seek treatment.
To evaluate the safety and efficacy of a home-use hair removal diode laser (TRIA Beauty, Inc., Dublin, CA) in a multiple treatment regimen.
Thirteen indicated adults with naturally brown or black hair and Fitzpatrick skin type I-IV received 8 monthly treatments with the diode laser at three fluences, with a fourth area left untreated as a control. Quantitative hair counts were made at each treatment visit and periodically for 12 months after the last treatment.
The treated sites exhibited statistically significant hair count reduction that generally increased with each treatment and remained stable during the 1 year follow-up period. The mean percent hair count reduction was 47%, 55%, and 73% at 1 month after the last treatment and 44%, 49%, and 65% at 12 months after the last treatment at fluences of 7, 12, and 20 J/cm(2) , respectively, compared to control. Eighty-six percent (86%) of subjects had greater than 30% hair reduction and 38% had >80% hair reduction at 12 months post-treatment. At the same time point, 31% of subjects reported complete (100%) hair removal and 69% reported that the hair that did regrow was less noticeable due to being finer and/or lighter. The only observed side effects were erythema and edema that were mild, transient, and self-resolving usually within a few hours.
The home-use diode laser was safe and highly effective at permanently reducing unwanted hair.
CryosurgeryCurettageElectrosurgeryInfrared coagulationCaustics and chemical peelingIntralesional therapySclerotherapyMiscellaneous physical proceduresSoft-tissue augmentation and facial line correctionLasers and flashlamps (intense pulsed light sources)Laser treatment of vascular and pigmented lesions and hair removalLaser resurfacing and non-ablative resurfacingPhotodynamic therapy
Background. Lasers with long wavelengths are less well absorbed by melanin and are considered to be particularly suitable for hair removal in dark-skinned patients.Objective. To compare the efficacy and complications of 800 nm diode and long-pulsed 1064 nm Nd:YAG lasers in laser-assisted hair removal in Chinese patients.Methods. Fifteen women had hair removal treatments (13 axillae and 2 legs) with diode laser on one side and Nd:YAG laser on the other. They were followed up for 36 weeks. Subjective assessments included the degree of immediate pain and the degree of hair regrowth. Clinical photographs were taken for evaluation by two independent observers to assess complications and the degree of hair regrowth.Results. Long-pulsed Nd:YAG laser was found to be significantly associated with a greater degree of immediate pain after laser surgery (P = .0001, independent sample t-test) and also had a longer laser time (P = .0001, independent sample t-test). Besides transit adverse effects such as erythema and perifollicular edema, only one patient developed hypopigmentation at week 6 which resolved by week 36. Although regrowth rates were low at week 6 (subjective rates were 23% and 19% for Nd:YAG and diode laser, respectively), most patients had significant regrowth at week 36 (subjective regrowth rate 91% for both long-pulsed Nd:YAG and diode lasers).Conclusion. Diode 800 nm and Nd:YAG 1064 nm lasers are safe in laser-assisted hair removal in Chinese patients, and besides immediate pain, there was no other significant adverse effect. Most patients experienced regrowth 36 weeks after a single treatment. Further study is necessary to determine the long-term clinical efficacy and complications of laser-assisted hair removal with these systems in dark-skinned patients.
In the last couple of decades, a number of laser and light-based technologies have been developed for hair removal that specifically
target hair follicles and allow for the potential treatment of large areas with long-lasting results. Laser hair removal works
by sending a beam of laser light to a group of hair follicles. The light energy causes thermal injury to the follicles. This
occurs because laser light is converted into heat as it passes through the skin and is absorbed in the target pigment melanin
found in the hair follicle. This process is called selective photothermolysis. The procedure is described and possible complications
discussed.
Most of the studies of laser-induced damage do not analyze individual cells. Objective of this work was to evaluate local photo-induced thermal phenomena in single cells at theoretical and experimental levels for developing the method for real-time detection of laser damage in intact cells.
Theoretical model of cell-laser interaction assumes local nature of photo-induced thermal effects and describes photodamage through bubble formation. Photothermal (PT) method was suggested for damage detection. Laser-induced damage was verified for individual cells with two techniques through detection of Trypan blue penetration into damaged cell.
Specific PT responses from blast-transformed lymphocytes were identified independently as result of bubble formation and cell damage. Probability of cell damage was obtained for cells as function of laser pulse energy.
The Laser load test (LLT) was suggested for real-time detection of damage, damage threshold measurement, and investigation of intact single cells.
Literature Review
Singlet oxygen, a metastable state of normal triplet oxygen, has been identified as the cytotoxic agent that is probably responsible for in vitro inactivation of TA-3 mouse mammary carcinoma cells following incorporation of hematoporphyrin and exposure to red light. This photodynamic inactivation can be completely inhibited by intracellular 1,3-diphenylisobenzofuran. This very efficient singlet oxygen trap is not toxic to the cells nor does it absorb the light responsible for hematoporphyrin activation. We have found that the singlet oxygen-trapping product, o-dibenzoylbenzene, is formed nearly quantitatively intracellularly when both the furan and hematoporphyrin are present during illumination but not when only the furan is present during illumination. The protective effect against photodynamic inactivation of the TA-3 cells afforded by 1,3-diphenylisobenzofuran coupled with the nearly quantitative formation of the singlet oxygen-trapping product indicates that singlet oxygen is the probable agent responsible for toxicity in this system. © 1976, American Association for Cancer Research. All rights reserved.
Hirsutism, a troublesome cosmetic problem, may also be a sign of serious systemic disease that can be screened for by means of the patient's history, physical examination, and certain basic blood tests. Most patients with functional hirsutism have elevated production rates of testosterone, elevated metabolic clearance rates of testosterone, depressed levels of sex hormone-binding globulin, and elevated levels of serum-free testosterone and hair follicle sensitivity. Once a neoplastic source is ruled out and hirsutism established as functional, essentially empiric treatment, including low-dose dexamethasone, oral contraceptives, and spironolactone, has proved to be effective.
Background and Design:
The clinical objective in the treatment of a patient with port-wine stain (PWS) undergoing laser therapy is to maximize thermal damage to the PWS, while at the same time minimizing nonspecific injury to the normal overlying epidermis. With dynamic cooling, the epidermis can be cooled selectively. When a cryogen spurt is applied to the skin surface for an appropriately short period of time (on the order of tens of milliseconds), the cooling remains localized in the epidermis, while leaving the temperature of the deeper PWS vessels unchanged.Results:
Comparative measurements obtained by a fast infrared imaging detector demonstrated that the surface temperature prior to laser exposure could be reduced by as much as 40°C using the dynamic cooling technique. No skin surface textural changes were noted on PWS test sites cooled with a 20- to 80-millisecond cryogen spurt after flashlamp-pumped pulsed dye laser (FLPPDL) exposure (λ=585 nm; τp=450 microseconds) at the maximum light dosage possible (10 J/cm2). In contrast, epidermal necrosis occurred on the uncooled sites after such exposure. Six months after laser exposure, clinically significant blanching on the cooled sites indicates laser photothermolysis of PWS blood vessels did occur.Conclusions:
Our preliminary experiments demonstrate the feasibility of selectively cooling the normal overlying epidermis without affecting the temperature of the deeper PWS vessels. Furthermore, protection of the epidermis from thermal injury, produced by melanin light absorption at clinically relevant wavelengths, can be achieved effectively. An additional advantage of dynamic epidermal cooling is reduction of patient discomfort associated with FLPPDL therapy. Further studies are under way to determine an optimum strategy for applying this dynamic cooling technique during pulsed laser treatment of patients with PWS and others with selected dermatoses (dermal melanocytic lesions and tattoos).(Arch Dermatol. 1995;131:695-700)
Physical methods for the management of unwanted hair are critically reviewed. Electrolysis and thermolysis are popular and medically proven electrochemical and electrosurgical techniques for permanent hair removal. Many patients seek consultation with their physician prior to having this elective procedure performed. Clinical guidelines are presented for a successful consultation with such patients. Many years ago the unregulated practice of x-ray therapy by unlicensed and poorly trained personnel resulted in tragic morbidity and mortality. Some historical parallels exist between this disturbing period and present day electrolysis and thermolysis practice: only twenty-seven states currently require licensing for permanent hair removal, which is a procedure with rare but potentially serious complications.
Excess body hair, or hirsutism, is usually only a problem in women and can cause considerable psychological distress. The disorder is usually androgen mediated. Because androgens come only from the adrenal glands or gonads or by conversion in peripheral tissues of precursor steroids from these organs, the causes of hirsutism are found in these two organs. Adrenal causes include Cushing's disease, adrenal tumors, and congenital adrenal hyperplasia. Ovarian causes include tumors, polycystic ovarian syndrome, and most cases of idiopathic hirsutism. The clinical evaluation is designed to differentiate between these diagnostic possibilities. When an underlying abnormality can be identified, such as an ovarian tumor, the treatment course is clear. When the diagnosis is idiopathic hirsutism, however, the best treatment is uncertain and several available regimens are possible.
Suitably brief pulses of selectively absorbed optical radiation can cause selective damage to pigmented structures, cells, and organelles in vivo. Precise aiming is unnecessary in this unique form of radiation injury because inherent optical and thermal properties provide target selectivity. A simple, predictive model is presented. Selective damage to cutaneous microvessels and to melanosomes within melanocytes is shown after 577-nanometer (3 x 10(-7) second) and 351-nanometer (2 x 10(-8) second) pulses, respectively. Hemodynamic, histological, and ultrastructural responses are discussed.
An integrated review of the transfer of optical radiation into human skin is presented, aimed at developing useful models for photomedicine. The component chromophores of epidermis and stratum corneum in general determine the attenuation of radiation in these layers, moreso than does optical scattering. Epidermal thickness and melanization are important factors for UV wavelengths less than 300 nm, whereas the attenuation of UVA (320-400 nm) and visible radiation is primarily via melanin. The selective penetration of all optical wavelengths into psoriatic skin can be maximized by application of clear lipophilic liquids, which decrease regular reflectance by a refractive-index matching mechanism. Sensitivity to wavelengths less than 320 nm can be enhanced by prolonged aqueous bathing, which extracts urocanic acid and other diffusible epidermal chromophores. Optical properties of the dermis are modelled using the Kubelka-Munk approach, and calculations of scattering and absorption coefficients are presented. This simple approach allows estimates of the penetration of radiation in vivo using noninvasive measurements of cutaneous spectral remittance (diffuse reflectance). Although the blood chromophores Hb, HbO2, and bilirubin determine dermal absorption of wavelengths longer than 320 nm, scattering by collagen fibers largely determines the depths to which these wavelengths penetrate the dermis, and profoundly modifies skin colors. An optical "window" exists between 600 and 1300 nm, which offers the possibility of treating large tissue volumes with certain long-wavelength photosensitizers. Moreover, whenever photosensitized action spectra extend across the near UV and/or visible spectrum, judicious choice of wavelengths allows some selection of the tissue layers directly affected.
Although many temporary treatments exist for hirsutism and hypertrichosis, a practical and permanent hair removal treatment is needed.
Our purpose was to study the use of normal-mode ruby laser pulses (694 nm, 270 microseconds, 6 mm beam diameter) for hair follicle destruction by selective photothermolysis.
Histologically assessed damage in ex vivo black-haired dog skin after the use of different laser fluences was used to design a human study; 13 volunteers with brown or black hair were exposed to normal-mode ruby laser pulses at fluences of 30 to 60 J/cm2, delivered to both shaved and wax-epilated skin sites. An optical delivery device designed to maximize light delivery to the reticular dermis was used. Hair regrowth was assessed at 1, 3, and 6 months after exposure by counting terminal hairs.
Fluence-dependent selective thermal injury to follicles was observed histologically. There was a significant delay in hair growth in all subjects at all laser-treated sites compared with the unexposed shaven and epilated control sites. At 6 months, there was significant hair loss only in the areas shaved before treatment at the highest fluence. At 6 months, four subjects had less than 50% regrowth, two of whom showed no change between 3 and 6 months. Transient pigmentary changes were observed; there was no scarring.
Selective photothermolysis of hair follicles with the normal-mode ruby laser produces a growth delay consistent with induction of prolonged telogen with apparently permanent hair removal in some cases.
Laser-assisted hair removal with the long pulsed ruby laser is a promising new technique based on selectively targeting melanin in hair follicles.
The purpose of this study was to evaluate the efficacy and safety of the long pulsed ruby laser (EpiTouch) for hair removal.
The Epitouch laser was used for hair removal of the arms of 20 patients. The areas were evaluated immediately post-treatment, and at 1, 4, 8, and 12 weeks, for efficacy and complications.
Postoperative results showed 40-80% regrowth after 12 weeks.
Selective melanin-based photothermolysis with a free running pulsed ruby laser seems to be a promising, noninvasive technique for long-term hair removal. More than one treatment is necessary since only anagen hair will be affected.
Determination of the efficacy of pulsed Alexandrite Laser technology for rapid noninvasive hair removal.
Although previous studies have already shown that Ruby lasers are capable of noninvasive hair removal, a technology for the substantial increase of treatment speed is of great interest.
We have used a 2 msec free running pulsed Alexandrite (lambda = 755 nm) laser operated at a repetition rate of up to 5 pps at energy fluences of 25-40 J/cm2 to treat a wide range of body sites on 126 patients in conjunction with a fiber delivery system and a transparent target ruler. A transparent gel was used as epidermal heat sink. The study lasted 15 months. Pretreatment as well as follow-up hair count per cm2 was performed to determine the level of success. Treatments were repeated when 1-2 mm growth was observed.
The average hair count before the second treatment was found to be close to 65% of the pretreatment count. The average hair count 3 months after the last treatment, was found to be lower than 12%. The interval between treatments ranged from 4 weeks to 3 1/2 months.
The 2 msec pulsed Alexandrite laser technology is effective for the removal of unwanted hairs, ranging from fair to dark, except when hairs are absent in the shaft depending on the stage of their growth cycle. This results in the necessity of a few treatments or touchups. Adverse effects are minimal and transient.
