Barriers to Completing Preoperative Hair Removal for Penile Inversion Vaginoplasty.

Penile inversion vaginoplasty (PIV) is a gender-affirming surgical procedure where the skin of the penis and scrotum is reconstructed into the neovaginal lining. To prevent hair-bearing skin from becoming incorporated into the neovaginal canal, transgender patients are encouraged to undergo hair removal of their external genitalia. The goal of this preoperative hair removal is to minimize the risk of potential hair-related complications after vaginoplasty. To better support patients seeking preoperative hair removal and identify current treatment barriers, we surveyed patients about their progress and satisfaction with hair removal. A cross-sectional survey was constructed to assess patient experiences with hair removal in advance of PIV. Sixty-seven patients met the inclusion criteria, of which 46 participated (68.7%). Both laser hair removal (LHR) and electrolysis were used. Although all patients had completed some preoperative hair removal at the time of survey (average of 14 sessions), the cohort completed only two-thirds of their total expected hair clearance. Multiple peri-procedural pain management therapies were employed, but overall satisfaction with pain management was low (57.4 ± 5.0 out of 100). LHR was associated with significantly lower procedural pain compared to electrolysis (p < .001). The average global satisfaction with the hair removal process was 57.9 ± 5.7 and incidents of mistreatment were associated with a statistically significant reduction in overall satisfaction (p = .02). Most patients felt that hair removal was important prior to surgery. Overall, LHR and electrolysis were both utilized as effective preoperative hair removal modalities; however, LHR has better pain tolerability than electrolysis.

Effects of pubic hair grooming on women's sexual health: a systematic review and meta-analysis.

BACKGROUND: Pubic hair grooming involves the partial or complete removal of pubic hair, and it is a common practice among men and women. Grooming is more prevalent in women, who employ various methods such as shaving, waxing and laser removal. However, it is associated with variable rates of post-grooming adverse outcomes including lacerations and sexually transmitted infections (STIs). To the best of our knowledge, this is the first systematic review and meta-analysis comparing women's sexual health outcomes between those who groom and those who don't. METHODS: We followed the MOOSE guidelines and conducted a computerized-based search using (PubMed, Web of Science, Scopus, and Ovid Medline), till June 20th, 2022, for eligible studies using the relevant keywords; (pubic hair grooming) OR (pubic hair removal OR Genital hairless OR Bikini hair removal OR pubic hair depilation). Cross-sectional studies included which compared grooming practices among women in terms of motivation and health outcomes. Women's satisfaction and incidence of STIs were pooled as standardized mean difference (SMD) and odds ratio (OR) respectively. RESULTS: Twenty-Two cross-sectional studies were included in our review with 73,091 participant.The odds of having gram-negative gonorrheal and chlamydial infection in Pubic hair groomers were found to be statistically significant (OR = 1.55, 95% CI [1.31, 1.84], P < 0.001) (OR = 1.56, 95% CI [1.32, 1.85], P < 0.001] respectively. There was no difference between groomer and non-groomer women regarding viral infections such as genital herpes (OR = 1.40, 95% CI [0.56, 3.50], P = 0.47) and Condyloma acuminata (OR = 1.75, 95% CI [0.51, 6.01], P = 0.37). The most common grooming side effect is genital itching (prevalence = 26.9%, P < 0.001). Non-electrical razor (prevalence = 69.3%, P < 0.001) is the most common grooming method. White women (prevalence = 80.2%, P < 0.001) remove pubic hair more frequently compared to black women (prevalence = 12.2%, P < 0.001). Women practice complete grooming (50.3%, P < 0.001) of the pubic hair more frequently than partial grooming (33.1%, P < 0.001). There are no differences in women's satisfaction between the two groups (SMD = 0.12, 95% CI [-0.16, 0.40], P = 0.39). CONCLUSION: This review aligns with previous observational studies regarding sexual health outcomes of pubic hair grooming. There is a need to raise awareness among women regarding the safe practice of pubic hair grooming, emphasizing the clarification of hazards and benefits.

Multispectral near-infrared spectroscopy study evaluating the effect of razor design on shaving-induced erythema.

BACKGROUND: While shaving-induced erythema is a common inflammatory skin issue, there is a lack of quantitative information on how well a shaving product performs in this regard. In this study, multispectral near-infrared spectroscopy (NIRS) imaging was used to quantitatively and qualitatively measure the extent of shaving-induced erythema. The research compares a safety razor and a cartridge razor to evaluate their impact on skin irritation. MATERIALS AND METHODS: Fifty-nine healthy male volunteers without pre-existing skin conditions were enrolled. Basic demographics were recorded, and participants' faces or necks were imaged before shaving. Shaving was conducted on the right side of the face/neck with the safety razor and on the left side of the face/neck using the 3-blade cartridge razor. Images were captured immediately after shaving, at 5 and 10 min post-shaving. RESULTS: Tissue oxygen saturation (StO2) measurements demonstrated that the safety razor induced significantly less erythema than the cartridge razor. Immediately after shaving, 40.3% of skin shaved with the safety razor had erythema compared to 57.6% for the cartridge razor. At 5 min post-shaving, 36.5% of skin shaved with the safety razor had erythema, compared to 53.8% of cartridge razor. CONCLUSIONS: Multispectral NIRS revealed significant differences in shaving-induced erythema between safety and cartridge razors. Safety razors demonstrated a lower incidence of erythema, suggesting a potential advantage for individuals prone to skin irritation. This study contributes valuable insights into skin irritation and highlights the potential of multispectral NIRS in dermatology research.

Efficacy of laser hair removal in hidradenitis suppurativa: A systematic review and meta-analysis.

OBJECTIVES: Hidradenitis suppurativa (HS) is a chronic inflammatory condition characterized by painful nodules, draining tunnels, and fibrotic scarring in intertriginous, hair-bearing areas. The pathogenesis involves follicular occlusion and subsequent rupture, leading to uncontrolled inflammation. Treatment options for HS are limited and lack universal effectiveness. Laser hair removal (LHR) has been explored as a potential treatment; however, the efficacy and appropriate laser modalities remain unclear. This systematic review examined the efficacy and adverse effects of LHR in HS. METHODS: A comprehensive literature search was conducted from inception to September 2023 in Ovid MEDLINE, Ovid Embase, and The Cochrane Library (Wiley) with predefined inclusion and exclusion criteria, and a meta-analysis was conducted. RESULTS: Ten studies were selected (n = 227 total patients) and included six randomized controlled trials, two nonrandomized experimental studies, and two case series. Various laser modalities, including long-pulsed neodymium-doped yttrium aluminum garnet (Nd:YAG) (n = 115), intense pulsed light (n = 18), Alexandrite (n = 54), intralesional 1064 nm diode (n = 20), and combined fractional CO2 and long-pulsed Nd:YAG laser (n = 20), consistently demonstrated significant improvement in HS disease severity, irrespective of the disease scoring method used. Minimal adverse effects (primarily mild pain and erythema) were reported. A meta-analysis of three studies utilizing long-pulsed Nd:YAG laser demonstrated a standardized mean difference in disease severity of -1.68 (95% confidence interval: -2.99; -0.37), favoring treatment with LHR for HS. CONCLUSIONS: Hair follicles are key in HS pathogenesis and all included studies showed a significant improvement in HS disease severity after LHR regardless of the laser device used, likely related to hair follicle unit destruction. HS is a complex and heterogenous condition, and multiple disease scoring methods complicate outcome comparisons across studies. However, LHR, utilizing various techniques, is an effective treatment option for HS with minimal adverse effects.

A review of hair removal modalities in pediatric patients: Ethical and clinical considerations.

Unwanted hair is a common concern among patients presenting to pediatric dermatology clinics, and parents and patients alike inquire about the safety of methods employed for elective removal. Various methods of hair removal exist with different levels of invasiveness and permanence, from simple mechanical depilation to light-based therapies. All methods of hair removal appear to be safe and generally well tolerated in children, and there are no age restrictions to any modality. In this review, we aim to address the available literature on the safety and efficacy of hair removal modalities in pediatric patients and propose guidance on how to manage requests for at-home and in-office therapies within an ethical framework.

Double-Blind Comparison of Eyelash Epilation Techniques for the Purpose of Demodex folliculorum Mite Retrieval.

OBJECTIVE: Demodex folliculorum blepharitis is typically confirmed with lash epilation and microscopic identification of mites. However, mite counts may vary with the epilation technique. As there is no gold standard to epilating lashes for the purposes of mite counts, the aim of this study was to compare three epilation techniques. METHOD: A prospective randomized double-blind study compared three epilation techniques on lashes with cylindrical dandruff. Techniques included (A) direct pulling of the lash; (B) rotating the lash before epilation; and (C) sliding the cylindrical dandruff away, lash rotation, and epilation. Mean mite counts were analyzed using a repeated-measures analysis of variance. RESULTS: Forty (n=40) participants (20 M: 20 F, mean age of 62.3±17.1 years) revealed similar mite counts between right (1.43±1.74) and left (1.35±1.59) eyes ( P =0.63). A significant difference ( P =0.03) in mite count was noted (technique A: 1.05 ± 1.60; technique B 1.76 ± 1.80; and technique C 1.36 ± 1.54) with technique B yielding the highest mite count ( P =0.04). CONCLUSION: Demodex mite count is a key parameter in establishing infestation or to determine treatment efficacy. This study revealed that rotating the lash before epilation yielded the highest mite count. Future studies should report the epilation technique used to allow for study comparisons.

Non-pigmented laser hair removal mediated via sepia melanin nanoparticles: in vivo study on albino mice.

OBJECTIVES: Melanin is considered the main chromophore for laser hair removal. Due to a lack of laser-absorbing chromophores, removing non-pigmented hair with laser is quite problematic with unsatisfactory outcomes. This problem could be solved by delivering more melanin to the area around the hair follicle and enhancing that area as a target for light absorption. The insolubility of Sepia melanin as an exogenous dye, in most solvents, limits its bioavailability and thus its clinical use. METHODS: In our study, to overcome the solubility problems and increase the bioavailability of melanin for biomedical and cosmetic applications, natural sepia melanin was loaded in different nano-delivery systems (spanlastics and transfersomes) to be delivered to the hair follicles. The different formulations of melanin were prepared and characterized. In vivo skin deposition and histopathological studies were conducted on albino mice. RESULTS: Transmission electron microscopy (TEM) showed the spherical shape of the prepared vesicles with an average particle size of 252 and 262 nm and zeta potential of -22.5 and -35 mV for melanin spanlastics and melanin transfersomes, respectively. Histopathological examination of hair follicles and pilosebaceous glands for the irradiated and non-irradiated albino mice skin was studied post the application of the prepared formulations topically and subcutaneously. Qualitative statistical analysis was conducted and melanin transfersomes and melanin spanlastics showed significant damage to pilosebaceous glands and hair follicles with a p-value of 0.031 and 0.009 respectively. CONCLUSION: Melanin nanovesicles as transfersomes and spanlastics could be considered a promising approach for the removal of non-pigmented hair.

Clinical Application of Long-Pulsed 800-Nm Diode Laser Depilation Technology on Microtia Reconstruction in 965 Patients.

BACKGROUND: The issue of hair growth on reconstructed ears has been a matter of concern for both patients and surgeons, despite the notable progress made in microtia reconstruction technology in recent times. OBJECTIVE: This study aims to present the practical implementation of long-pulsed 800-nm diode laser depilation technology in the field of auricular reconstruction. Furthermore, it seeks to establish a comprehensive and standardized protocol for utilizing lasers in the reconstruction of microtia ears. METHODS: A total of 965 patients (comprising 1021 ears) diagnosed with congenital microtia underwent treatment using 800-nm long-pulsed diode laser depilation. The participants received 1-3 treatment sessions with intervals of 25-30 days. To assess the effectiveness of the treatment, two independent observers compared photographs and measured the reduction in terminal hair count before and after the final session. Clinical outcomes were evaluated using VAS questionnaires, and any adverse events were diligently recorded. RESULTS: The findings indicated that the utilization of the long-pulsed 800-nm diode laser was both safe and efficient in achieving hair removal during microtia ear reconstruction. As additional sessions were conducted, pain scores demonstrated a decline, while adverse reactions remained minimal. LIMITATIONS: This is a retrospective single-institution study. CONCLUSION: The application of a long-pulsed 800-nm diode laser has been proved to be a safe and effective method for removing hair during the process of microtia ear reconstruction, involving the use of a tissue expander and autologous costal cartilage. To achieve satisfactory results in hair removal, it was found necessary to repeat the shots procedure two to three times. LEVEL OF EVIDENCE IV: This journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to the Table of Contents or the online Instructions to Authors www.springer.com/00266 .

Mechanical epilation exerts complex biological effects on human hair follicles and perifollicular skin: An ex vivo study approach.

OBJECTIVE: Electrical epilation of unwanted hair is a widely used hair removal method, but it is largely unknown how this affects the biology of human hair follicles (HF) and perifollicular skin. Here, we have begun to explore how mechanical epilation changes selected key biological read-out parameters ex vivo within and around the pilosebaceous unit. METHODS: Human full-thickness scalp skin samples were epilated ex vivo using an electro-mechanical device, organ-cultured for up to 6 days in serum-free, supplemented medium, and assessed at different time points by quantitative (immuno-)histomorphometry for selected relevant read-out parameters in epilated and sham-epilated control samples. RESULTS: Epilation removed most of the hair shafts, often together with fragments of the outer and inner root sheath and hair matrix. This was associated with persistent focal thinning of the HF basal membrane, decreased melanin content of the residual HF epithelium, and increased HF keratinocyte apoptosis, including in the bulge, yet without affecting the number of cytokeratin 15+ HF epithelial stem cells. Sebocyte apoptosis in the peripheral zone was increased, albeit without visibly altering sebum production. Epilation transiently perturbed HF immune privilege, and increased the expression of ICAM-1 in the bulge and bulb mesenchyme, and the number of perifollicular MHC class II+ cells as well as mast cells around the distal epithelium and promoted mast cell degranulation around the suprabulbar and bulbar area. Moreover, compared to controls, several key players of neurogenic skin inflammation, itch, and/or thermosensation (TRPV1, TRPA1, NGF, and NKR1) were differentially expressed in post-epilation skin. CONCLUSION: These data generated in denervated, organ-cultured human scalp skin demonstrate that epilation-induced mechanical HF trauma elicits surprisingly complex biological responses. These may contribute to the delayed re-growth of thinner and lighter hair shafts post-epilation and temporary post-epilation discomfort. Our findings also provide pointers regarding the development of topically applicable agents that minimize undesirable sequelae of epilation.

OBJECTIF: L'épilation électrique des poils indésirables est une méthode d'épilation largement utilisée, mais on ne connaît pas l'ampleur de son effet sur la biologie des follicules pileux humains (FP) et de la peau périfolliculaire. Dans cette étude, nous avons commencé à explorer comment l'épilation mécanique modifie certains paramètres de mesures biologiques clés ex vivo à l'intérieur et autour de l'unité pilo­sébacée. MÉTHODES: Des échantillons de peau du cuir chevelu humain de pleine épaisseur ont été épilés ex vivo à l'aide d'un dispositif électromécanique, cultivés biologiquement pendant un maximum de 6 jours dans un milieu complet sans sérum, et évalués à différents moments par (immuno­)histomorphométrie quantitative pour certains paramètres de mesures pertinents dans des échantillons avec épilation et des échantillons témoins avec épilation simulée. RÉSULTATS: L'épilation a enlevé la plupart des poils, souvent avec des fragments de la gaine de la racine externe et de la matrice pileuse. Cela a été associé à un amincissement focal persistant de la membrane basale du FP, à une diminution de la teneur en mélanine de l'épithélium résiduel du FP et à une augmentation de l'apoptose des kératinocytes du FP, y compris dans la surface arrondie, mais sans affecter le nombre de cellules souches épithéliales du FP positives pour la cytokératine 15. L'apoptose des sébocytes de la zone périphérique était augmentée, sans pour autant altérer visiblement la production de sébum. L'épilation a temporairement perturbé l'immunoprivilège du FP et a augmenté l'expression de l'ICAM­1 dans la surface arrondie et le mésenchyme du bulbe, ainsi que le nombre de cellules périfolliculaires du CMH de classe II et des mastocytes autour de l'épithélium distal, et a favorisé la dégranulation des mastocytes autour de la zone supra­bulbaire et bulbaire. En outre, par rapport aux échantillons témoins, plusieurs acteurs clés de l'inflammation neurogène cutanée, de la démangeaison et/ou de la thermosensation (TRPV1, TRPA1, NGF et NKR1) ont été exprimés de manière différentielle dans la peau après l'épilation. CONCLUSION: Ces données générées dans la peau du cuir chevelu humain dénervée et cultivée biologiquement démontrent que le traumatisme du FP induit par l'épilation mécanique provoque des réponses biologiques étonnamment complexes. Celles­ci peuvent contribuer à retarder la repousse des poils plus fins et plus clairs après l'épilation, et à provoquer une gêne temporaire après l'épilation. Nos résultats fournissent également des pistes concernant le développement d'agents applicables par voie topique qui minimisent les séquelles indésirables de l'épilation.

What are the Factors That Induce Paradoxical Hypertrichosis After Laser Hair Removal?

BACKGROUND: Laser hair removal (LHR) is one of the most requested cosmetic procedures worldwide. A rare side effect is the appearance of excess hair around previously treated areas, known as paradoxical hypertrichosis. OBJECTIVES: The aim of this study was to retrospectively identify the cause of this side effect. METHODS: This study included all patients who underwent LHR at our center between November 2018 and November 2020. Alexandrite laser hair removal (HR) or diode laser super hair removal (SHR) was performed in 70% and 30% of cases, respectively. Clinical features and daily habits of patients with and without postlaser hypertrichosis were compared. RESULTS: Of the 7381 patients who received LHR, 25 patients (0.34%) demonstrated an increase in hair growth compared to baseline. Of these 25 patients, 24 had been treated with alexandrite laser HR (P < .01). The most common site was the upper arm, followed by the periareolar area. Daily sun protection was associated with a significantly lower incidence of hypertrichosis (P < .05), as was confirmed and shown to be independent of Fitzpatrick skin type by binary logistic regression analysis (odds ratio = 0.41, P < .05). CONCLUSIONS: In our clinic, we observed paradoxical hypertrichosis after laser hair removal in a small minority of cases, as described by others. We did not observe differences in incidence related to skin type, but daily sun protection and LHR with diode laser SHR were associated with significant reductions in incidence rates. In addition to previously reported common sites, we also identified the periareolar area as a high-risk region.

Comparative effectiveness of ice packs versus topical lidocaine-prilocaine mixture for pain control in laser hair removal of the axilla: A rater-blinded randomized controlled trial.

BACKGROUND: Laser hair removal is associated with moderate acute pain. OBJECTIVE: To compare effectiveness of ice pack to topical lidocaine-prilocaine for pain reduction during axillary laser hair removal. METHODS: Participants were randomly assigned to receive topical anesthetic to one axilla and ice packs to the other before each of 3, monthly 810 nm diode laser sessions. The primary endpoint was participant-reported pain on the visual analog scale (VAS) immediately following and 5 minutes after laser session. Posttreatment erythema, overall edema, and perifollicular edema were assessed by 2 blinded photoraters. Skin temperatures, patient preferences, and adverse events were recorded. RESULTS: Eighty-eight of 90 (98%) planned laser treatments were delivered and randomized. Participants reported higher VAS scores immediately after laser treatment with lidocaine-prilocaine compared to ice (P = .03). Five minutes after, participants reported higher VAS scores with ice (P = .03). After 53 of the 88 treatments (60.2%), participants reported preferring ice (P = .055). No serious adverse events were reported. LIMITATIONS: All participants were Caucasian or Asian with Fitzpatrick skin type I to III and coarse dark axillary hair, which may limit generalizability. CONCLUSIONS: While pain control with ice and topical anesthesia is associated with time after treatment, the 2 modalities do not differ in terms of degree of pain reduction associated with axillary laser hair removal.

The dermatologist's guide to beards: a review of structure, function, care and pathology.

Facial hair is a commonly desired feature for many individuals. Despite a breadth of dermatology literature covering strategies for removing facial hair, there are no known articles summarizing strategies for facial hair growth or reviewing common facial hair pathologies. Here, we assess Google Trends to describe significant increases in search terms related to facial hair growth and maintenance over the last decade, suggesting an increased public interest in this topic. Next, we review ethnic differences that may affect facial hair distribution, growth, and predisposition to certain facial hair pathologies. Lastly, we review studies on agents used for facial hair growth and review common facial hair pathologies.

Review of treatments for pseudofolliculitis barbae.

Pseudofolliculitis barbae (PFB) is a chronic inflammatory condition characterized by follicular and perifollicular papules and pustules primarily affecting the beard and neck area. PFB is a condition that predominantly affects patients with skin of colour. The objective of this paper is to review the epidemiology, pathogenesis and presentation of PFB, and assess the most recent evidence-based treatment options and recommendations for PFB. This is important to increase the quality of care given to target patient populations and to address the prominent disparity in healthcare management of patients with skin of colour. A literature review was conducted utilizing PubMed and Cochrane Library. The key term 'pseudofolliculitis barbae' was used. Search parameters were set to search from 1987 to the present. Results were further narrowed by limiting the literature review to published observational studies, case studies, case series, randomized control trials and case-control studies. Effective treatment for PFB requires a multifaceted approach that targets various aspects of the pathogenesis. Current treatments include preventive measures, antibiotics, corticosteroids, keratolytics, chemical depilatories and/or laser treatments. Topical therapies are currently the mainstay treatment. However, laser hair removal has become a potential long-term treatment option, and additional studies are warranted to understand its long-term efficacy and permanency.

Unintentional macular injury following high-energy cosmetic laser calibration.

Unwelcome hair has become a significant issue encountered in our society by young people, particularly young women. Hair removal has been achieved through various methods, both mechanical, with intense pulse light therapy and laser photoablation of hair follicles using various energy delivery systems. There is a relative paucity of clinical trials comparing the safety and efficacy of various hair removal modalities. A comparative study between alexandrite, diode, and intense pulsed light (IPL) was conducted and found similar safety profile across all three modalities. Several adverse effects have been noted as a result of this therapy. Laser-assisted hair removal can lead to ocular anterior segment and/or retinal injury. A laser beam directed toward the eye may easily penetrate both the eyelid or the cornea and cause catastrophic ocular injury. Unfortunately, regulation and licensing of the use of laser-assisted hair removal devices has not yet been well elucidated nor standardized across Australia. There are few cases in the literature reporting retinal burns following inadvertent laser injury, with even fewer directly involving the macula. We report a case of unilateral anterior uveitis and a macular defect following inadvertent laser exposure, leading to photophobia and pain, and reduced visual acuity.

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.

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.

Measurements of hair temperature avalanche effect with alexandrite and Nd:YAG hair removal lasers.

BACKGROUND AND OBJECTIVES: In this study, we investigate the photothermal response of human hair using a pulsed laser source employed in the hair removal treatment. The purpose is to understand the dynamics behind the most common clinical practice to better define the salient features that may contribute to the efficiency of the process. STUDY DESIGN/MATERIALS AND METHODS: Temperature changes of hair samples (dark brown color) from a human scalp (skin type Fitpatrick II) were measured by a thermal camera following irradiation with single and multiple neodymium: yttrium-aluminum-garnet (Nd:YAG) (1064 nm) and alexandrite (755 nm) laser pulses. Particularly, the hair was treated with an individual laser pulse of a sufficiently high fluence, or with a series of lower fluence laser pulses. We investigated the temperature increase in a broad range of fluence and number of pulses. From the data analysis we extrapolated important parameters such as thermal gain and threshold fluence that can be used for determining optimal parameters for the hair removal procedure. Our experimental investigations and hypothesis were supported by a numerical simulation of the light-matter interaction in a skin-hair model, and by optical transmittance measurements of the irradiated hair. RESULTS: An enhancement of the temperature response of the irradiated hair, that deviates from the linear behavior, is observed when hair is subjected to an individual laser pulse of a sufficiently high fluence or to a series of lower fluence laser pulses. Here, we defined the nonlinear and rapid temperature built-up as an avalanche effect. We estimated the threshold fluence at which this process takes place to be at 10 and 2.5 J/cm2 for 1064 and 755 nm laser wavelengths, respectively. The thermal gain expressed by the degree of the deviation from the linear behavior can be higher than 2 when low laser fluence and multiple laser pulses are applied (n = 50). The comparison of the calculated gain for the two different laser wavelengths and the number of pulses reveals a much higher efficiency when low fluence and multiple pulses are delivered. The avalanche effect manifests when the hair temperature exceeds 45°C. The enhanced temperature increase during the subsequent delivery of laser pulses could be ascribed to the temperature-induced changes in the hair's structural properties. Simulations of the hair temperature under Nd:YAG and alexandrite irradiation indicate that the avalanche phenomenon observed in the hair suspended in air may apply also to the hair located within the skin matrix. Namely, for the same fluence, similar temperature increase was obtained also for the hair located within the skin. CONCLUSION: The observed "avalanche" effect may contribute to the reported clinical efficacy of laser hair removal and may at least partially explain the observed efficacy of the brushing hair removal procedures where laser fluence is usually low. The repeated irradiation during the brushing procedure may lead to an avalanche-like gradual increase of the hair's thermal response resulting in sufficiently high final hair temperatures as required for effective hair reduction.

Combination 1550 nm non-ablative fractional resurfacing and laser hair removal for treatment of Becker's nevi in skin types III-VI.

OBJECTIVES: Becker's nevus is a cosmetically bothersome benign hamartoma typically associated with basal layer hyperpigmentation and hypertrichosis. We herein present the largest case series characterizing treatment parameters and clinical outcomes of combined 1550 nm non-ablative fractional resurfacing and laser hair removal (long-pulsed neodymium-doped yttrium aluminum garnet or alexandrite) in the treatment of Becker's nevus. This is also the largest case series of laser treatment of Becker's nevus in Fitzpatrick skin types V and VI. METHODS: We performed a retrospective review of patients treated between 2016 and 2021. Clinical photographs were graded by three independent physicians using a 5-point visual analog scale. RESULTS: Twelve patients (mean age: 24.8 years, Fitzpatrick skin types III-VI) were treated for Becker's nevus on the face (4) or the trunk and/or extremities (8). Four patients were Fitzpatrick skin types V or VI. On average, patients received 5.3 treatments in 1-4-month intervals. Ten of the 12 patients had concomitant laser hair removal preceding same-day non-ablative fractional resurfacing (n = 7 with long-pulsed 1064 nm neodymium-doped yttrium aluminum garnet and n = 3 with long-pulsed 755 nm alexandrite). The number of treatments with each modality was determined by patient satisfaction with improvement in hyperpigmentation and hypertrichosis. At follow-up, which ranged from 6 to 40 weeks (mean 10.5 weeks), patients were given a mean improvement score of 51%-75%. No long-term adverse events were encountered in either group. Limitations include a small sample size and a lack of long-term follow-up. CONCLUSION: Combination 1550 nm non-ablative fractional resurfacing and laser hair removal is safe and efficacious in the cosmetic reduction of hyperpigmentation and hypertrichosis associated with Becker's nevus, including those with Fitzpatrick skin types V and VI.

Handheld dermatoscope versus digital camera for hair counts in laser facial hair removal.

The lack of uniform and objective techniques to evaluate treatment efficacy in photo-epilation studies leads to contradictory results. Thus, there is an urgent need to explore commonly accepted assessment tools. One of the most common methods uses hair counts via digital photography. However, macrophotography may not be able to depict the vellus-like hair induced by photo-epilation. On the other hand, handheld dermatoscopy is practical, affordable and offers high-quality magnification. Hair counts from a handheld dermatoscope and a digital camera were compared in 73 women who underwent 6 sessions with the Alexandrite 755 nm laser. Significantly more hairs were counted using the dermatoscope than using the digital camera (76.9 ± 41.3 vs. 58.6 ± 31.4, p < .005), independently of hair thickness and hair density. The difference in hair counts between the two instruments was inversely related to hair thickness and directly related to hair density. The handheld dermatoscope may be a more effective tool than the widely used digital camera in evaluating the response to laser hair removal treatment.

Umbilical seborrheic keratosis-like lesion developing after diode laser hair removal in an 18-year-old patient.

OBJECTIVE: to report a possibly novel complication of laser hair removal. CASE REPORT: a white-skinned 18-year-old patient discovered an umbilical, brown, and raised lesion while shaving before his second diode laser hair removal session. He sought consultation before his fourth laser session since the lesion further thickened and darkened. Dermoscopy showed no pigmented network, but a few comedo-like openings within an erythematous-light brown scaly and fissured papule, "moth-eaten" borders, and a central crust due to manipulation, suggesting the diagnosis of seborrheic keratosis. We noted that the laser fluence was increased on the umbilical region where hair seemed resistant to treatment. The patient denied a recent history of local sun tanning, sunburns, inflammation, drainage, or manipulation. The lesion cleared, with no short-term relapse, after one session of cryotherapy. CONCLUSION: the development of a seborrheic keratosis-like lesion on a densely haired non-sun-exposed umbilicus of a young patient, following pre-laser shaving and high-fluence hair removal diode laser sessions, could have implicated triggering irritation and/or keratinocyte stimulation by red light-engendered reactive oxygen species (ROS) in the skin with silent epidermal mosaicism.