A clinical overview of hair removal using lasers and light sources

Awareness and knowledge of laser hair removal: a cross sectional study from tertiary care dermatology clinics in Oman

BACKGROUND

Laser hair removal (LHR), including the use of home-based devices, is becoming very popular in Oman. Despite this, some people still have many misconceptions about this procedure, especially of its long-term complications. This study aimed to assess the awareness and knowledge of LHR among dermatology clinic attendees in Muscat, Oman.

METHODS

A cross sectional survey study was conducted at Al Seeb and Bowshar polyclinics in Muscat, Oman, to attendees between the ages of 18 and 70 years. The Chi-square test was used to assess the association between different categorical variables. Results were considered to be statistically significant if P < 0.05.

RESULTS

Of the 500 questionnaires which were distributed, 403 were completed (response rate = 80.6%). The mean (± standard deviation [SD]) age of participants was 32.9 (8.5) years old. In this study, 45.7% (184/403) of participants had used LHR, and of those, 88.6% (163/184) were satisfied with the results. The knowledge percentage among individuals was higher among those who used LHR compared to those who did not use LHR (46% vs. 27%, respectively; P < 0.001). However, there were no significant differences in LHR knowledge percentages based on employment status or monthly income. Female participants and subjects with an educational level of a college degree or above had superior knowledge regarding the safety of LHR use during pregnancy (P < 0.05).

CONCLUSIONS

This study noted a lack of knowledge, with various misconceptions, about LHR among patients attending dermatology clinics in Oman, especially in individuals who had not used LHR before.

Changes in melanocytic nevi treated with laser hair removal: A systematic review

BACKGROUND

Incidental treatment of melanocytic nevi during laser hair removal (LHR) has been noted to cause clinical and dermoscopic changes that may appear similar to findings seen in atypical or neoplastic melanocytic lesions. The rate and characteristics of these changes has not been well-studied.

OBJECTIVES

The objective of this review article is to assess the literature for reported changes in melanocytic nevi following LHR to guide clinical practice.

METHODS

PubMed was searched December 5, 2022 for articles evaluating changes in melanocytic nevi after LHR treatment using the following search terms: "nevi laser hair removal," "nevi diode," "nevi long pulse alexandrite," "nevi long pulse neodymium doped yttrium aluminum garnet," and "melanoma laser hair removal." All English language patient-based reports discussing incidental treatment of melanocytic nevi while undergoing LHR with a laser were eligible for inclusion, while reports of changes following hair removal with non-laser devices such as intense pulsed light were excluded. Studies evaluating non-melanocytic nevi such as Becker's nevus or nevus of Ota were excluded as were those evaluating the intentional ablation or removal of melanocytic lesions.

RESULTS

Ten relevant studies were included, consisting of seven case reports or series and three observational trials, two of which were prospective and one retrospective. Among the seven case reports or series there were a total of 11 patients, six of which had multiple affected nevi. Clinical and dermoscopic changes to nevi following LHR appear to be common in clinical practice, though not well studied. Clinical and dermoscopic changes have been noted to present as early as 15 days after treatment and persist to the maximum time of follow up at 3 years. Commonly reported changes include regression, decreased size, laser induced asymmetry, bleaching, darkening, and altered pattern on dermoscopy. Histologic changes include mild atypia, thermal damage, scar formation, and regression. Although some of the clinical and dermoscopic alterations may be concerning for malignancy, to our knowledge, there are no documented cases of malignant transformation of nevi following treatment with LHR.

LIMITATIONS

This study is limited by the low number of relevant reports and their generally small sample size, many of which is limited to single cases. Additionally, comparison of available data was limited by variable reporting of treatment regimens and outcomes.

CONCLUSIONS

Changes to nevi treated during LHR are not uncommon. Modifications to nevi may occur and look similar to changes seen in dysplastic or neoplastic melanocytic lesions. Notably, despite the widespread use of LHR since the first device was Food and Drug Administration approved in 1995, a time span of nearly three decades, there have been no reported cases of melanoma or severe dysplastic changes within treated nevi. However, dermatologists should be aware that morphologic and dermoscopic alterations can occur after LHR to prevent unnecessary surgical procedures. Although melanoma has not been reported to occur in nevi treated with LHR nor with any other laser exposures, further long-term data is needed to fully elucidate this concern. Optimally, nevi should be examined by a dermatologist before LHR to determine a baseline clinical and dermoscopic morphology. If there is concern for potential atypia, laser should be avoided over such nevi to avoid confusion at future follow up visits.

Dermoscopic changes in melanocytic nevi following hair removal laser: A prospective study

BACKGROUND

Changes in the appearance of melanocytic nevi have been increasingly reported following hair removal lasers. This could be a source of anxiety in patients doing cosmetic hair removal lasers. Moreover, taking biopsy of any changed nevus following laser is not routinely practical. Therefore, this study was designed to describe dermoscopic changes happened on acquired junctional melanocytic nevi after photo-depilation methods.

METHOD

In this prospective study, 66 melanocytic nevi in 27 patients were chosen. Dermoscopic images were taken at the baseline visit and 2 months following single session of hair removal laser. Afterward, the before and after laser images were compared for any change in the structure and color of the nevi.

RESULTS

Dermoscopic images showed alterations in nevi following laser including changes in size in 33%, color in 63.6%, newly developed asymmetry in 12.1%, and regression in 3% of nevi. Besides, alteration in reticular and dots and globules pattern was found in 92.5% and 69.32%, respectively.

CONCLUSIONS

Hair removal laser could induce considerable changes in appearance of acquired junctional melanocytic nevi. Dermoscopic study before and after the process could help to avoid unnecessary excision of suspected lesions.

Long-term outcome of a patient with paradoxical hypertrichosis after laser epilation

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 and 22 J/cm² at 10-12-week intervals over a course of seven treatments. After three 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 biannual 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.

Review of the progress toward achieving heat confinement-the holy grail of photothermal therapy

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.

Management of Polycystic Ovary Syndrome

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.

From flint razors to lasers: a timeline of hair removal methods

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.

"We feel rejected": experiences of women with hirsutism consulting physicians

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.

Comparative evaluation of long pulse Alexandrite laser and intense pulsed light systems for pseudofolliculitis barbae treatment with one year of follow up

Background:

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.

Aims:

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.

Methods:

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.

Results:

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.

Conclusions:

Our results showed that both systems might improve PFB but Alexandrite laser was more effective at reducing PFB than IPL.

Hair removal with an Athos Nd:YAG 3.5 ms pulse laser: a 3-month clinical study

INTRODUCTION/OBJECTIVE

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.

METHODS

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.

RESULTS

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.

CONCLUSION

Results from this study show that the Athos Nd:YAG is efficient and safe for removing pigmented hair in phototypes I-IV.

"It is always on my mind": women's experiences of their bodies when living with hirsutism

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.

[Novel adverse effects of laser-assisted axillary hair removal]

BACKGROUND

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.

OBJECTIVE

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.

PATIENTS AND METHODS

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.

RESULTS

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.

CONCLUSION

Hyperhidrosis, bromhidrosis and leukotrichia are likely new adverse effects of laser-assisted axillary hair removal.

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 Results of Axillary Hair in Dark-Skinned Patients by IPL: A Comparison Between Different Wavelength and Pulse Width

BACKGROUND

Recently, intense pulsed light (IPL) sources have been shown to provide long-term hair removal.

OBJECTIVE

This study examined the photo-epilatory effects of different wavelengths and pulse width application in the same IPL device and compared their efficiencies in Asian skin.

METHODS

Twenty-eight Korean women were treated using hair removal (HR) (600-950 nm filter) and 27 using HR-D (645-950 nm filter) in the axillary 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 6 2.0 J/cm2 for HR and 17.1 6 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 removing 45 nm of the emitted spectra and applying a longer pulse width was found to provide a safer and more effective means of photo-epilation in Asian patients.

Hair induction after laser-assisted hair removal and its treatment

BACKGROUND

Laser hair removal is a relatively safe procedure with limited side effects. Hair induction has been previously scarcely reported.

OBJECTIVE

We sought to report the incidence of this strange side effect in a large number of patients treated for hair removal and to follow its course and treatment.

METHODS

We conducted retrospective analysis of the files of all patients who underwent laser hair removal during the time period from May 1998 until May 2005 in a private institution in Athens, Greece.

RESULTS

Hair induction occurs predominantly on the face and neck of female patients of Mediterranean ancestry with darker skin types. The percentage is quite low (4.5%). Laser treatment of the induced hair reduces the problem.

LIMITATIONS

No control groups could be obtained in this study. Furthermore, the natural course of hair induction could not be studied because it was always treated or patients were lost to follow-up.

CONCLUSIONS

Hair induction is a rare side effect of laser hair removal occurring in selected populations and body areas; however, it responds well to laser treatments.

Epilation today: physiology of the hair follicle and clinical photo-epilation

Despite the variations of length and type of hair (vellus or terminal), the growth of human hair in all body sites is cyclic. Phases of active hair growth, or anagen, are separated by periods of quiescence, or telogen. The duration of both phases varies greatly depending on the body site. Whether hairs are in anagen/telogen at the time of hair removal is important because only anagen hairs are particularly sensible to physical insults. Photo-epilation is a technique for long-term removal of unwanted hair by thermal destruction of the hair follicle and its reproductive system (stems cells). As melanin is the main chromophor existing in hair follicles the corresponding wavelength spectrum would range from ultraviolet up to infrared light. Furthermore longer wavelengths are preferred as the cromophor lies deep in the skin and the penetration of light is increasing with the wavelength. Thus, in the range of 600-1100 nm melanin absorption may be used for selective photothermolysis of hair follicles. Yet to be resolved questions for permanent destruction are the location of the key follicular target and the possible influence of the hair growth cycle on photothermolysis-induced hair removal. An overview on the individual physiology of the hair follicle is given to discuss the latest strategies for photo-epilation.

Modified superlong pulse 810 nm diode laser in the treatment of pseudofolliculitis barbae in skin types V and VI

BACKGROUND

Laser hair removal is a well-established therapy for pseudofolliculitis barbae, but there have been few studies on the use of a very-long-pulse 810 nm diode laser for this condition.

OBJECTIVE

To determine the efficacy and tolerability of a modified 810 nm superlong-pulse diode laser (Palomar Medical, Burlington, MA, USA) in the treatment of pseudofolliculitis barbae (PFB) in subjects with type V and VI skin.

METHODS

Thirteen patients were treated three times at 2-week intervals on one side of their neck with varying fluences. They were evaluated for (1) reduction of shaving bumps and (2) pain tolerance on the treated versus the untreated side.

RESULTS

There was a statistically significant improvement in shaving bumps. The treatment side showed a baseline PFB lesion count of 22.5 (+/- 20 SD), which decreased to a mean of 5 (+/- 5 SD) (p<.05). The control baseline mean count was 27.6 (+/- 22 SD) and at the end of the study was 15 (+/- 12 SD) (p = .13). Pain was rated at 2.5 of 10 for subjects treated both with and without anesthetic. The margin of safety was greater in type V compared with type VI skin.

CONCLUSION

A modified 810 nm superlong-pulse diode laser is both effective and well tolerated in the reduction of shaving bumps, especially in patients with type V skin.

Photothermal detection of laser-induced damage in single intact cells

BACKGROUND AND OBJECTIVE

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.

STUDY DESIGN/MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSIONS

The Laser load test (LLT) was suggested for real-time detection of damage, damage threshold measurement, and investigation of intact single cells.

Causes and management of hypertrichosis

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.

Photothermal time-resolved imaging of living cells

BACKGROUND AND OBJECTIVES

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.

STUDY DESIGN/MATERIALS AND METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

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.

Photodisruptive laser nucleation of ultrasonic cavitation for biomedical applications

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.

Alopecia areata-like hair loss in C3H/HeJ mice and DEBR rats can be reversed using topical diphencyprone

This study demonstrates the ability to treat successfully alopecia areata-like hair loss in both mouse and rat models using topical immunotherapy with diphencyprone.