Guidelines on the safety of light-based home-use hair removal devices from the European Society for Laser Dermatology

Is It Possible for Light-Based Hair Removal Home Devices to Induce Ocular Damage? Systematic Review

Light-based hair removal home devices emit intense pulse light (IPL) or Diode laser. While the Food and Drug Administration controls them in the US, Europe continues to classify them as cosmetic products. Emerging concerns are: what if an unprotected eye is inadvertently exposed to light emission? Or if the consumer tries to overcome the protective safety features? We performed this systematic review by searching the Medline, CENTRAL, and Google Scholar databases to investigate the ocular damage reported after exposure to IPL for hair removal. We could not identify any case reported following exposure to home devices; however, a total of 20 patients were identified with iris atrophy, anterior chamber inflammation, and/or retinal pigment epithelium damage following exposure to office IPL or Diode lights. 40% were not using any protective eyewear during the light procedure. The reported fluences were in the range of 20-24 J/cm2. Although the ocular damage was identified following office devices, the reported fluences were within the home device's limits. For that, manufacturers should provide clear instructions on the package regarding the ocular hazards, the importance of using protective goggles, and a firm warning not to overcome the contact sensors. Home device-induced ocular damage is still a concern, perhaps under-reported.

Assessment of adverse events for a home-use intense pulsed light hair removal device using postmarketing surveillance

BACKGROUND AND OBJECTIVES

Home-use intense pulsed light (IPL) hair removal devices are convenient for consumers. Consumer safety associated with home-use IPL devices, however, remains a subject of interest. In this descriptive analysis, we assessed the most commonly reported adverse events (AEs) for a home-use IPL device from postmarketing surveillance and qualitatively compared these with AEs from clinical studies and medical device reports of home-use IPL treatments.

MATERIALS AND METHODS

For this analysis of voluntary reports, we queried a distributor's postmarketing database for IPL devices for the period beginning January 1, 2016, to December 31, 2021. All sources of comments, for example, phone, e-mail, company-sponsored web sites, were included in the analysis. AE data were coded according to the Medical Dictionary for Regulatory Activities (MedDRA) terminology. Also, we conducted a PubMed search to identify AE profiles from existing literature on home-use IPL devices and we searched the Manufacturer and User Facility Device Experience (MAUDE) database for reports on home-use IPL devices. These results were qualitatively compared to the data in the postmarketing surveillance database.

RESULTS

A total of 1692 cases involving IPL were identified from voluntary reports of AEs between 2016 and 2021. The shipment-adjusted reporting rate for AE cases (number of AE cases/100,000 shipped IPL devices) was 67/100,000 during this 6-year period. The most commonly reported AEs were pain of skin 27.8% (470/1692), "thermal burn" 18.7% (316/1692), and erythema 16.0% (271/1692). Among the top 25 AEs reported, no unexpected health events were observed. The reported AEs were qualitatively similar to the pattern seen in clinical studies and the MAUDE database associated with such home-use IPL treatments.

CONCLUSION

This is the first such report documenting AEs for home-use IPL hair removal from a postmarketing surveillance program. These data are supportive of the safety of such home-use low-fluence IPL technology.

Will repeated Intense Pulsed Light (IPL) treatment sessions affect facial skin sensitivity? Results of a twelve-Month, prospective, randomized split-face study

BACKGROUND

Despite the widespread use of intense pulsed light (IPL) technology in cosmetic dermatology, the effects of its repeated use on facial skin sensitivity in healthy individuals remains unknown.

METHODS

Seventeen healthy female volunteers were included in the study. We measured objective biophysical parameters of the skin, including transepidermal water loss (TEWL), skin glossiness, thickness and density of the epidermis and dermis, sensory nerve current perception threshold (CPT), and regional blood flow before and after treatment at different time points.

RESULTS

Sixteen volunteers completed a follow-up of 12 months. The treated side of the face showed a decreased TEWL on D1 and D3, which reverted to normal on D7. Epidermal thickness increased and skin glossiness decreased on the treated side on D1, but returned to normal on D3. We found no statistically significant differences in CPT values or in regional blood flow volume and velocity, with the exception of D1, which exhibited a higher regional blood flow volume on the treated side.

CONCLUSION

Repeated IPL treatments had no effects on facial skin barrier function, skin nerve sensitivity, or local microcirculation among healthy individuals. IPL is a safe skin care procedure that does not affect skin sensitivity.

Light-based home-use hair removal devices: A cross-sectional survey

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Intended Human Exposure to Non-ionizing Radiation for Cosmetic Purposes

Cosmetic devices using non-ionizing radiation (NIR) are increasingly available for people who wish to modify their appearance for aesthetic purposes. There are a wide range of NIR modalities used for cosmetic procedures, including devices that use optical radiation (laser, intense pulsed light, and light-emitting diode), electromagnetic fields, and ultrasound. Common procedures involving the application of NIR include epilation, skin rejuvenation, body sculpting and contouring, treatment of vascular and skin lesions, tattoo removal, and scar reduction. The majority of research on the use of NIR cosmetic devices has focused on the efficacy of the treatment rather than adverse effects or complications. Studies that assessed safety consisted mostly of case reports and small case series. Common adverse effects on the skin reported include mild and transient pain, erythema, swelling, and changes in pigmentation. Less common, more severe side effects include burns, blisters, scarring, persisting erythema, altered pigmentation, and eye damage. Some of the latter may have resulted from treatment errors. Particular groups of people that may be at greater risk from optical radiation include people with dark skin, with high sun exposure, and taking photosensitizing medications or supplements. There is lack of evidence for the safety profile of cosmetic NIR procedures during pregnancy. Reports of injuries to workers administering treatments with cosmetic NIR devices are rare, but inadvertent damage to the eye from optical devices may occur. Randomized controlled trials are required to fully assess potential adverse effects from the use of NIR cosmetic devices. Regulation varies worldwide and some regions apply the same safety classification and guidance as for medical devices. In order to reduce harm associated with the use of cosmetic devices, ICNIRP considers it important that regulations that cover all types and frequencies of cosmetic NIR devices are adopted worldwide and that there is greater oversight regarding their use.

Polycystic Ovary Syndrome: Pathophysiology, Presentation, and Treatment With Emphasis on Adolescent Girls

Polycystic ovary syndrome (PCOS) is a heterogeneous disorder characterized by hyperandrogenism and chronic anovulation. Depending on diagnostic criteria, 6% to 20% of reproductive aged women are affected. Symptoms of PCOS arise during the early pubertal years. Both normal female pubertal development and PCOS are characterized by irregular menstrual cycles, anovulation, and acne. Owing to the complicated interwoven pathophysiology, discerning the inciting causes is challenging. Most available clinical data communicate findings and outcomes in adult women. Whereas the Rotterdam criteria are accepted for adult women, different diagnostic criteria for PCOS in adolescent girls have been delineated. Diagnostic features for adolescent girls are menstrual irregularity, clinical hyperandrogenism, and/or hyperandrogenemia. Pelvic ultrasound findings are not needed for the diagnosis of PCOS in adolescent girls. Even before definitive diagnosis of PCOS, adolescents with clinical signs of androgen excess and oligomenorrhea/amenorrhea, features of PCOS, can be regarded as being “at risk for PCOS.” Management of both those at risk for PCOS and those with a confirmed PCOS diagnosis includes education, healthy lifestyle interventions, and therapeutic interventions targeting their symptoms. Interventions can include metformin, combined oral contraceptive pills, spironolactone, and local treatments for hirsutism and acne. In addition to ascertaining for associated comorbidities, management should also include regular follow-up visits and planned transition to adult care providers. Comprehensive knowledge regarding the pathogenesis of PCOS will enable earlier identification of girls with high propensity to develop PCOS. Timely implementation of individualized therapeutic interventions will improve overall management of PCOS during adolescence, prevent associated comorbidities, and improve quality of life.

Dose-response of human follicles during laser-based hair removal: Ex vivo photoepilation model with classification system embracing morphological and histological features

OBJECTIVES

Photoepilation is a commonly used technology in home-use devices (HUDs) and in professional systems to remove unwanted body hair using pulses of laser or intense pulsed light (IPL). Albeit HUDs and professional systems operate at different fluences and treatment regimes, both demonstrate high hair reduction. The underlying mechanisms, however, remain unknown partly due to high divergence of the existing literature data. The objective of this study was to develop an ex vivo photoepilation model with a set of criteria evaluating response to light pulses; and to investigate dose-response behavior of hair follicles (HFs) subjected to a range of fluences.

METHODS

After ex vivo treatment (single pulse, 810 nm, 1.7-26.4 J/cm² , 4-64 ms pulse) human anagen HFs were isolated and maintained in culture for 7-10 days. Response to light was evaluated based on gross-morphology and histological examination (H&E and TUNEL stainings).

RESULTS

HFs treated ex vivo demonstrated a dose-dependent response to light with five distinct classes defined by macroscopic and microscopic criteria. Fluences below 13.2 J/cm² provoked catagen-like transition, higher fluences resulted in coagulation in HF compartments.

CONCLUSION

Observed changes in the HF organ culture model were reflected by clinical efficacy. The developed photoepilation model provides an easy and fast method to predict clinical efficacy and permanency of light-based hair removal devices. Lasers Surg. Med. © 2019 Wiley Periodicals, Inc.

Light-based home-use devices for hair removal: Why do they work and how effective they are?

OBJECTIVES

This review has the following objectives: Firstly, it provides an explanation of the evolution of laser/intense pulsed light (IPL) hair reduction modalities from high fluence professional devices to low fluence home-use appliances. Secondly, it summarises published literature reviews on home-use devices (HUDs) as evidence of their growing credibility. Thirdly, it proposes mechanistic differences in light delivery regimes and the resulting divergences in mode of action.

MATERIALS AND METHODS

An extensive literature search was performed to review the progress of laser/IPL-induced hair reduction and determine what evidence is available to explain the mode of action of professional and HUDs for hair removal. Establishing the likely biological mode of action of professional high-fluence systems versus home-use low-fluence appliances was performed by combining data obtained using ex vivo hair follicle (HF) organ culture and the clinical results involving human participants.

RESULTS

Significant basic science and clinical evidence has been published to confirm the clinical efficacy and technical safety of many laser and IPL home-use devices for hair removal. Clearly, HUDs are different compared to professional systems both in terms of fluence per pulse and in terms of biological mechanisms underlying hair removal. Here we presented data showing that a single low fluence pulse of both 810 nm laser (6.6 J/cm² , 16 ms) and IPL (9 J/cm² , 15 ms and 6.8 J/cm² , 1.9 ms) leads to induction of catagen transition. Catagen transition was characterized by morphological changes similar to what occurs in vivo with occasional detection of apoptosis in the dermal papilla and outer root sheath cells. This suggests that high hair reduction can be expected in vivo and longer-term treatment might result in HF miniaturization due to a cumulative effect on the dermal papilla and outer root sheath cells. In line with this hypothesis, in this review we demonstrate that long-term application of a commercially-available home-use IPL appliance resulted in persistent hair reduction (80%) one year after last treatment. These data are in line with what was previously reported in the literature, where clinical studies with home-use IPL appliances demonstrated high efficacy of hair reduction on female legs, armpits and bikini zones, with full hair regrowth after four treatments following cessation of IPL administration. Limitations of HUDs include lack of hair clearance for very dark skin types and low speed of treatment compared with professional devices. Numerous uncontrolled and controlled clinical efficacy studies and technical safety investigations on consumer-use appliances support many of the leading manufacturers' claims.

ANALYSIS & CONCLUSIONS

Manufacturers make consumer appliances safe and easy to use by considering "human factors," needs and capabilities of a variety of users. Safety is of primary concern to manufacturers, regulators and standards bodies as these appliances may be accessible to children or their use attempted on unsuitable skin types without full awareness of potential side effects. Consumer cosmetic appliances are provided with warnings and obvious safety notices describing the nature of any ocular or dermal hazard and precautions for reducing risk of accidental injury, infection, etc. HUDs employing optical energy are provided with design and engineering controls such as safety switches, alarms and sensors to prevent their incorrect operation or eye exposure. In-vivo studies demonstrated that low fluence home-use hair removal devices can result in high hair reduction efficacy after a short treatment regime, while prolonged and less frequent (once in six weeks) maintenance treatment over a year can lead to high and sustained hair reduction even one year after cessation of treatment. Home-use hair removal devices can be a useful adjunct to professional in-office treatments with high professional awareness. There are sufficient positive arguments for practitioners to make the case to patients for HUDs as "companion" products to professional treatments. In addition, devices for hair removal can be used effectively as stand-alone products by the consumer if they are willing to adopt a regime of regular or frequent use. Further clinical studies involving dynamic observation of HF cycle stage and type (terminal vs. vellus) over the total duration of treatment, for example, using biopsies or non-invasive imaging are necessary to confirm the proposed mode of action of low fluence pulses in a combination with treatment and maintenance regimes. Lasers Surg. Med. 51:481-490, 2019. © 2019 Wiley Periodicals, Inc.

Comparison of Efficacy Between Novel Robot-Assisted Laser Hair Removal and Physician-Directed Hair Removal

OBJECTIVE

This study aimed to evaluate the number of laser irradiation sessions, process duration, and hair removal rate required for robot-assisted automatic versus physician-directed laser hair removal.

BACKGROUND DATA

This research group previously developed and tested an automatic laser hair removal (LHR) system to provide uniform laser treatment distribution.

METHODS

Six subjects 20-40 years of age, with skin types III-IV completed this study. A home-use LHR device with an 810 nm diode laser was used to treat equal-sized areas of both upper thighs; a random computer generator determined the use of a robot-assisted automatic LHR system or physician-directed LHR on the right or left thigh. The treatment schedule comprised five visits; subjects were photographed and shaved, and received LHR during the first through the fourth visits at 2-week intervals. The fifth visit occurred 1 month after the fourth, and only involved photography.

RESULTS

All subjects successfully completed the clinical trial with no noticeable or permanent side effects. The average hair removal rates were 49.0% (standard error of the mean [SEM]: 4.0) and 29.5% (SEM: 4.0) for robot-assisted and physician-directed LHR, respectively. The average treatment duration and number of irradiation shots were 18 min, 30 sec (SEM: 33 sec) and 260 (SEM: 5.7) for robot-assisted LHR and 3 min, 11 sec (SEM: 15 sec) and 73 (SEM: 5.9) for physician-directed LHR.

CONCLUSIONS

This clinical study successfully demonstrated the safety and effectiveness of robot-assisted LHR. The proposed novel system will benefit both patients and clinicians.

Ultraviolet radiation after exposure to a low-fluence IPL home-use device: a randomized clinical trial

The prevailing advice is to avoid sun exposure after intense pulsed light (IPL) hair removal. However, no systematic evaluation of ultraviolet radiation (UVR) after IPL hair removal exits. Therefore, we investigated the occurrence of side effects in subjects receiving solar-simulated UVR after a low-fluence IPL treatment with a home-use device. Sixteen subjects with Fitzpatrick skin types (FST) II-V were enrolled. Three constitutive buttock blocks (4.4 × 6.4 cm) were each subdivided into four sites, randomized to one IPL exposure of 0, 7, 8, or 10 J/cm2 (spectral output 530-1100 nm). Blocks were randomized to no UVR or three standard erythema doses (SEDs) UVR either 30 min or 24 h after IPL. Follow-up visits were 48 h, 1 week, and 4 weeks after IPL. Outcome measures were (i) clinical skin reactions, (ii) reflectance measurements of erythema and pigmentation, and (iii) pain. Subjects with FST II-IV experienced no skin reactions up to 4 weeks after IPL, neither erythema, edema, blisters, crusting, textual, nor pigment changes. Reflectance confirmed no change in erythema and pigmentation (p ≥ 0.090). UVR exposure induced erythema and increased pigmentation. The combination of IPL and UVR induced skin reactions not different to responses from UVR (IPL-UVR vs. UVR, p ≥ 0.164). Pain was generally low (median 1, range 0-4) and correlated positively with fluence and pigmentation (Spearman's rho ≥ 0.394, p < 0.001). One subject with FST V experienced perifollicular hyperpigmentation after IPL and slightly more intense when exposed to UVR. A single UVR exposure of three SEDs either shortly or 1 day after low-fluence IPL causes no amplification of skin responses in constitutive skin of individuals with FST II-IV.

Tool to visualize and evaluate operator proficiency in laser hair-removal treatments

BACKGROUND

The uniform delivery of laser energy is particularly important for safe and effective laser hair removal (LHR) treatment. Although it is necessary to quantitatively assess the spatial distribution of the delivered laser, laser spots are difficult to trace owing to a lack of visual cues. This study proposes a novel preclinic tool to evaluate operator proficiency in LHR treatment and applies this tool to train novice operators and compare two different treatment techniques (sliding versus spot-by-spot).

METHODS

A simulation bed is constructed to visualize the irradiated laser spots. Six novice operators are recruited to perform four sessions of simulation while changing the treatment techniques and the presence of feedback (sliding without feedback, sliding with feedback, spot-by-spot without feedback, and spot-by-spot with feedback). Laser distribution maps (LDMs) are reconstructed through a series of images processed from the recorded video for each simulation session. Then, an experienced dermatologist classifies the collected LDMs into three different performance groups, which are quantitatively analyzed in terms of four performance indices.

RESULTS

The performance groups are characterized by using a combination of four proposed indices. The best-performing group exhibited the lowest amount of randomness in laser delivery and accurate estimation of mean spot distances. The training was only effective in the sliding treatment technique. After the training, omission errors decreased by 6.32% and better estimation of the mean spot distance of the actual size of the laser-emitting window was achieved. Gels required operators to be trained when the spot-by-spot technique was used, and imposed difficulties in maintaining regular laser delivery when the sliding technique was used.

CONCLUSIONS

Because the proposed system is simple and highly affordable, it is expected to benefit many operators in clinics to train and maintain skilled performance in LHR treatment, which will eventually lead to accomplishing a uniform laser delivery for safe and effective LHR treatment.

The role of natural and UV-induced skin pigmentation on low-fluence IPL-induced side effects: a randomized controlled trial

BACKGROUND AND OBJECTIVES

The risk of adverse skin effects following light-based hair removal is greater in pigmented skin based on the theory of selective photothermolysis. Thus sunlight-induced pigment i.e., facultative pigmentation, increases the risk of adverse skin effects, perhaps disproportionately. The aim of this study was to evaluate the influence of constitutive and facultative skin pigmentation on low-fluence intense pulsed light (IPL)-induced adverse skin effects.

STUDY DESIGN/MATERIALS AND METHODS

Twenty-one subjects with Fitzpatrick skin type II-IV were enrolled. Two buttock blocks were randomized to receive 0 or 8 solar simulated ultraviolet radiation (UVR) exposures of consecutively increasing Standard Erythema Doses (2-4 SED). Each block was subdivided into four sites, randomized to receive IPL of 0, 7, 8, or 10 J/cm(2) , once a week for 3 weeks. Biopsies were taken 16-24 hours after the first IPL exposure and subjects were seen 1 and 4 weeks after the last IPL exposure. Outcome measures were: (i) skin reactions, (ii) pain, (iii) mRNA expression of pigment-markers microphthalmia-associated transcription factor (MITF) and pro-opiomelanocortin (POMC), and (iv) clinical appearance of biopsy wounds.

RESULTS

Skin pigmentation increased after UVR (baseline median 13.8%, after UVR 28.1%, P = 0.0001) in all skin types. Subjects reported low pain intensities (median 1.5, scale 0-10) and experienced transient erythema immediately after IPL exposure. No persistent erythema, blisters, crusting, textual, or pigment changes were observed. The risk of erythema and pain intensities increased with IPL dose and skin pigmentation (P < 0.03). There was no difference in pain or skin reactions in skin with similar degree of natural and facultative pigmentation (P ≥ 0.104). Expression of cellular pigment-markers was not influenced by IPL exposure, neither in constitutive nor in facultative pigmented skin. Clinical appearance of biopsy wounds was unaffected by IPL exposure.

CONCLUSION

The prevalence and intensity of low-fluence IPL-induced adverse skin effects depended on IPL dose and skin pigmentation regardless of the origin, i.e., constitutive versus UV induced.