Novel laser hair removal in all skin types

Abstract

Background

Laser has been long accepted as a solution for excess or unwanted hair growth yet traditional lasers are not always ideal for safe and effective outcome for all skin types and hair characteristics. A diode laser module combining three wavelengths (755, 810, and 1064 nm) in a single pulse was developed to provide a fast and long‐term solution for subjects with various profiles.

Aims

To evaluate the safety and efficacy of a Triple wavelength diode laser module for hair removal treatment in all skin types (Fitzpatrick I–VI).

Subjects and methods

This was a prospective, dual centered, single‐arm study. Subjects were treated with a novel diode laser module. Thirty‐six subjects were enrolled, sixteen with Fitzpatrick skin types I–IV (46%) and twenty with Fitzpatrick skin types V–VI (54%). Treatment areas were axilla and bikini lines. Subjects underwent 4 treatment sessions at 6 weeks ± 5 days intervals and attended a follow‐up visit 3 months after the last treatment session. 2D digital photographs were taken at baseline and at the follow‐up visit, and a hair count was conducted by three blinded evaluators.

Results

A significant reduction in hair count between baseline and the 3‐month follow‐up visit was observed in both axilla and bikini lines for all skin types. The mean hair reduction was 41.5 ± 19.4% and 48.1 ± 20.9% in the axilla and bikini line, respectively. A significant hair reduction was also observed within skin type groups; mean hair reduction 45.5 ± 16.9% and 40.3 ± 17.2% in skin types I–IV and V–VI, respectively, indicating similar efficacy for both light and dark skin types. No serious adverse events were reported.

Conclusions

This study demonstrates that the Soprano Titanium laser platform is safe and effective for hair removal treatment in all skin types.

INTRODUCTION

Unwanted hair is a prevalent condition that affects, in various degrees, up to 40% of the female worldwide. Undesired, sometimes excessive, hair growth may be normal, the side effect of medications, or a sign of an underlying pathological condition. Despite being biologically normal in the majority of cases, the presence of unwanted and excessive hair can be distressing to the affected individuals. Several studies have demonstrated that women with excessive body or facial hair were found to be at a higher risk of body dysmorphic disorder, which is characterized by a constant perception of ugliness and shame. Effective removal of unwanted hair may thus be critical to alleviating its adverse psychological impact. The current management lines for unwanted hair include medical management of any underlying clinical disorder, lifestyle modifications, and/or cosmetic treatments; the latter ranges from mechanical or chemical hair removal (such as creams, bleaching, shaving, or waxing) to the destruction of hair follicles through electrolysis or light-based therapies. Light-based hair removal has emerged as one of the most effective strategies for many dermatological conditions. Lasers are the most widely used phototherapy for hair removal. They act through thermal destruction of the targeted hair follicles, with minimal damage to the surrounding tissues (selective photothermolysis) and are currently the most effective method of long-term hair removal.

Laser systems developed over the past two decades encompass various wavelengths for hair removal include long pulse ruby at 694 nm, long pulse alexandrite (755 nm), long pulse diode (810 nm), and long pulse Nd:YAG (1064 nm). Generally, the current body of evidence shows that lasers exhibit excellent efficacy and safety profiles for unwanted hair removal in normal population. Nevertheless, the challenges of effective hair removal treatments, such as skin melanin content that acts as a competing chromophore for light absorption, affect both hair reduction efficacy and increase the risk of adverse events such as blistering and hyperpigmentation. This is most relevant in individuals with darker skin (phototypes III–VI). It has been shown that subjects with pigmented skin are more prone to laser-related adverse events such as pain, blistering, and dyspigmentation. To minimize the rate of adverse events in these individuals, prolonged pulse-width laser devices and longer treatment duration were proposed.

Factors such as skin type and hair color, as well as different levels of hair thickness and depth, affect the appropriate laser selection. Recently, devices presenting a combination of wavelengths have shown to produce high effective hair reduction with no related risks. Novel diode laser systems combining three wavelengths (755, 810, 1064 nm) in a single pulse have been developed to target different structures of the hair follicle for the removal of unwanted hair and to provide long-term hair reduction suitable for diverse hair varieties and all skin types. This study was designed to clinically evaluate the safety and efficacy of this novel combinational diode laser in patients of the entire range of skin types I–VI.

MATERIALS AND METHODS

Device

The laser device used was the Soprano Titanium (Alma Lasers LTD, Israel) with its large TRIO diode module (4 cm² spot size) that bare clustered technology that emits a combination of three wavelengths at 755, 810, and 1064 nm in every single pulse. Laser energy is delivered by a series of high repetitive low fluence pulses (Super Hair Removal—SHR mode), to increase the temperature of both the hair follicle and the surrounding tissue, by carrying the In-Motion™ technique. The constant motion technique gradually heats the surrounding tissue, allowing it to act as a reservoir of heat around the hair follicle. This process, along with the thermal energy absorbed directly by the hair follicle, damages the follicle and prevents re-growth. Energy is delivered via pulses emitted from a 2 cm² or 4 cm² spot size, to cover small and large areas, respectively, with pulse width ranging from 3–220 ms and fluence and frequency of up to 10 J/cm² and 10 Hz. The modules have an integrated metallic rim sapphire window using thermoelectric contact cooling system (4°C/39°F) to reduce patient discomfort and post procedure side effects.

Study methodology

This was a dual-site, prospective single-arm study, conducted between October 2020 and October 2021. The study was approved by the Advarra IRB ethical committee (Columbia, MD, USA), and was and was registered at (NCT04599751). Thirty-six female subjects over 18 years were enrolled in the study, seventeen of them with Fitzpatrick skin types I–IV (46%) and twenty with Fitzpatrick skin types V–VI (54%). Treatment areas included the axilla and bikini line. Main exclusion criteria included pregnancy, lactation, tanned skin, a history of laser or other hair removal methods in the treatment area, having a tattoo or an active infection in the treatment area, history of any chronic skin disease in the treatment area, a known history of photosensitivity, or consumption of steroids within 30 days before enrollment.

2D digital photographs of the treatment areas were taken at baseline, prior to each session and at the 3-month follow-up (3 M FU) visit for hair reduction assessment by manual hair count. Photographs were taken using a Nikon D5300 camera with uniform lighting and position conditions. Treatment areas were shaved and marked into pre-determined 2.5 cm² grids.

Chilled ultrasound gel was applied to allow easy movement of the module and topical cooling of the epidermis. Treatment parameters were 7–8 J/cm², and 13–14 kJ total energy for skin types I–III, and 4–6 J/cm², and 12–14 kJ total energy for skin types IV–VI. Treatment technique was carried out In-Motion™ where the module was kept in full contact with the skin and moved continuously over the entire treatment area until the set cumulative energy (in kJ) was reached. Subjects underwent 4 treatment sessions at 6 weeks ±5 days intervals. A follow-up visit was conducted 3 months after the last treatment session. Hair reduction was assessed using the physician Global Aesthetic improvement Scale (GAIS; scale of 0 [no improvement] to 4 [excellent improvement; Over 75% hair reduction]).

Photographs of baseline and final follow-up visit were assessed by three physicians; independent evaluators and observations were averaged and categorized according to the physician GAIS score (0%–100% scale). Hair counts at baseline and at 3 M FU after four sessions were counted (Figures  and ), and average percentage of hair reduction by site was calculated. Safety was evaluated by monitoring of any adverse events during and post treatments. In addition, tolerance to the treatment was assessed both by the investigators and the subjects before and after each treatment session. The investigators used the 5-point Likert scale in the following 4 categories: erythema, edema, dryness, and peeling, while the subjects used the same scale with different categories: stinging, tingling, itching, and burning.

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Statistical analysis

All tests were 2-tailed, and a p-value of 5% or less was considered statistically significant. The data were analyzed using SAS® software, version 9.4 or higher (SAS Institute, Cary, North Carolina).

RESULTS

Thirty subjects (mean age 36 years, range 18–62 y/o) of the thirty-six enrolled completed all four sessions of the study and attended the 3 M FU visit. Fourteen of those subjects had Fitzpatrick skin types I–IV (47%), and sixteen had Fitzpatrick skin types V–VI (53%). A total of 120 areas, which included 60 axillae (right and left) areas and 60 bikini lines (right and left), were treated. Treatment parameters applied were a fluence range of 3–9 J/cm², an accumulated energy range of 6–15 kJ, and a pulse repetition rate of 9–10 Hz.

Remarkable results of hair count reduction were observed in both treated areas (axilla and bikini line). Table  summarizes the percentage of hair count reduction (average of 3 evaluators) among skin types and treated areas. As seen in this table, there was a significant reduction in hair count between baseline and the 3-month follow-up visit in both treated areas (axilla and bikini line). The mean hair reduction in the axilla was 41.5 ± 19.4% (range 52.6–76.0), p < 0.0001, and in the bikini line 48.1 ± 20.9% (range 14.2–96.3), p < 0.0001. Interestingly, the results were even better when calculated per skin type. The mean hair reduction in skin type I–IV was 45.5 ± 16.9% (range 5.4–77.9), p < 0.0001, and in skin type V–VI 40.3 ± 17.2% (range 36.5–63.8), p < 0.0005. In addition, in each treatment area, for both skin types, there was a significant hair reduction (p < 0.05). No serious adverse events were recorded throughout the study. Anticipates adverse events were transient and resolved with no need for intervention. Subject's satisfaction from the treatment as evaluated by a 5-point Likert scale questionnaire at the 3 M FU visit was high. As shown in Figure , Median satisfaction rate from axilla treatment ranged from 3.25 to 3.75 among treated subjects (n = 14); Median satisfaction rate from bikini lines treatment was 4 among treated subjects (n = 16); and Median satisfaction rate when calculating both body areas ranged from 3.75 to 3.88 among all treated subjects, (n = 30).

TABLE 1 Relative change (%) from baseline to 3 M FU in hair count in all subjects.

Relative change in hair count	Skin type I–IV	Skin type V–VI	All skin types
Mean	Std	p-Value	Mean	Std	p-Value	Mean	Std	p-Value
Axilla	−43.4	17.1	0.0003	−39.8	21.2	0.0136	−41.5	19.4	<0.0001
Bikini line	−49.5	20.1	<0.0001	−47	21.8	0.0001	−48.1	20.9	<0.0001
Average sections	−45.5	16.9	<0.0001	−40.3	17.2	0.0019	−42.7	17.1	<0.0001

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DISCUSSION

The ability to adjust and integrate wavelengths arises as a promising solution for the safe and effective removal of unwanted hair that will benefit all skin types. This study presents the results of thirty subjects treated with combined laser wavelengths in the axilla and bikini line. Very few studies assessed hair removal in those area. Khoury et al. showed 67.1 ± 15.1% of hair reduction in the axillary area. In this study, the subjects also rated the improvement of their treatment, and the mean result was 4 out of 5. All the reported side effects were transient and resolved within 2 days of onset. Furthermore, Raj Kirit et al. reported 76% hair reduction in the bikini area within 6 treatment sessions, and no adverse events were recorded throughout the study. The current study's results are comparable to those of previous similar studies. All thirty subjects demonstrated a significant hair reduction; mean hair reduction for both treated areas was 45.5 ± 16.9% and 40.3 ± 17.2% for subjects with Fitzpatrick skin types I–IV and V–VI, respectively. The mean hair reduction for all skin types was 41.5 ± 19.4% and 48.1 ± 20.9% in the axilla and bikini line, respectively. The moderate hair reduction results obtained in this study are attributed to the low number of sessions (4) as compared to the other mentioned studies. In addition, while the subjects in the current study were divided into skin type groups I–IV and V–VI, in the above mentioned two studies, subjects with skin types I–III and IV–V, respectively, were treated.

Consistently with the other studies reported above, no serious or unanticipated adverse events were reported. In all studies, the adverse events were mild to moderate and transient.

In the current study, satisfaction from the hair removal treated was assessed at rates of 3.75 ± 1.16, 3.88 ± 0.92, and 3.75 ± 1.02 in a 1–5 scale for the axilla, bikini line, and total for all treatment areas, respectively. These results indicate high satisfaction from the treatment. In the study conducted by Khoury et al. the subjects rated the improvement of their treatment slightly higher, with a mean score of 4 out of 5. However, it should be noticed again that only subjects with Fitzpatrick skin types I–III were enrolled in the study.

To conclude, this study demonstrates that the use of laser module that combines three wavelengths (755, 810, and 1064 nm) in a single pulse is safe and effective for removal treatment in all skin types. The significant reduction in hair counts among all skin types, together with its high safety profile, makes it an attractive tool for hair removal treatments suitable for all skin types. In addition, the use of the unique in-motion technique to provide high repetition and short pulses results in gradual heating of the dermis to reduce hair growth and causes minimal damage to skin and less pain. The study was conducted on a relatively small sample size which consisted of female only. Another limitation of the study is the relatively short follow-up of 3 months. A longer follow-up period of 6 or 9 months would have been more effective in determining the treatment's long-term effects. Therefore, additional studies on hair removal with laser devices combining three wavelengths in a single pulse, and at least 6 months follow-up period are required to support the insights achieved in this study.

AUTHOR CONTRIBUTIONS

The authors contributed to the design and implementation of the research, to the analysis of the results, and to the writing of the manuscript.

ACKNOWLEDGMENTS

Editorial assistance was performed by Angela Brown.

DISCLOSURES

Dr. Gold performs clinical research for Alma Lasers.

DATA AVAILABILITY STATEMENT

The authors confirm that the date supporting the finding of this study are available within the article

ETHICAL APPROVAL

The paper reflects the authors’ own research and analysis in a truthful and complete manner.

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