Evaluation of Safety and Efficacy of Laser Hair Removal With the Long‐Pulsed 755 nm Wavelength Laser: A Two‐Center Study With 948 Patients

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.

Using "Appointment Tickets" to Track Visit Duration as a Quality Improvement Initiative After Incorporating Laser Epilation in a Pilonidal Care Clinic

BACKGROUND

Laser epilation (LE) is effective in decreasing pilonidal disease (PD) recurrence, but laser use has not been a standard practice in pediatric surgery clinic. We hypothesized that "appointment tickets" can 1) track utilization and clinic visit delays, 2) inform patients of their clinic progress in real time.

METHODS

An observation study was performed on LE patients treated at our PD clinic 3/2021-7/2022. Two exam rooms were utilized for manual shaving and one for LE. After gluteal cleft hair shaving, various anesthetic (topical lidocaine, ice, or cryotherapy) was applied prior/during LE. At each visit, patient received an "appointment ticket" on which providers recorded the visit start/end time, manual shaving duration, local anesthetic application/wait time, LE duration. Visits were scheduled for 20 min-slots. Clinic staff recorded any delays (>20 min).

RESULTS

1317 visits were recorded. Mean number of visits per week was 18 ± 6. Mean total visit length was 60 ± 22 min, mean shaving time 15 ± 11 min, mean anesthetic application/wait time 16 ± 11 min, mean LE time 14 ± 9 min. Over the study period, average visit length has decreased, and average visits/clinic day has increased. Most delays occurred in months April, May, October-December. Delays due to patient late arrival occurred in May, July, and August of 2021, none in 2022.

CONCLUSIONS

LE visits have multiple components that required close coordination to ensure no clinic delays. Clinic delays spiked prior to summer and winter holidays. "Appointment tickets" provided patients with real-time visit progress tracked clinic utilization to improve the quality of pilonidal care delivery.

LEVEL OF EVIDENCE

Level IV.

Trunk hair removal treatment with diode laser 810 nm in men population

In the last years, hair removal has been one of the most common treatments performed for aesthetic purposes, especially in women. Nevertheless, even if it is less popular, the demand within men population has risen. The study aimed to assess the acceptability of the diode 810 nm treatment for hair removal on the back and chest area in men thanks to the speed of treatment and the absence of undesirable effects. For this study, 20 patients were treated for hair removal. They were men with a mean age of 30.5 (±7.3). They underwent 4 treatment sessions at 40-day intervals on the trunk (chest and back area). Patients ranged between a Fitzpatrick phototype I (20%, 4/20) to IV (15%, 3/20) (40% were type II and 25% type III). Moreover, patients were asked to report pain intensity sensation with a visual analogue scale. Overall, in the study population, a hair reduction of 80.6% (±2.8) was registered in the treated areas. The device described in this study was demonstrated to be highly efficient in extended body areas and on difficult-to-treat hair follicles like on the back and chest in the men population.

Effects at cellular level of epilation with various laser wavelengths applied simultaneously on different skins: two case reports

This study evaluated the effects of laser application of diverse wavelengths applied simultaneously and on different skins. The sample included two participants, a woman with light skin with abdominal hair and a woman with dark skin and hair on the inner part of the lower limbs, who received a laser therapy session. After 45 days from laser application, abdominoplasty and thigh dermolipectomy surgery were performed. In the control sample, the hair follicles were in the anagen phase, showing the presence of Bcl-2 expression. In the treated areas, follicles were observed in an advanced phase (telogen), with the presence of CK-18 and negativity of Bcl-2, highlighting the phase of hair loss at that moment and the complete apoptosis of the investigated follicle. Significant difference was observed in the comparison of the anagen phase (p = .00) and it similarly occurred in the comparison of the telogen phase (p = .00). The presence of a greater amount of follicles in the anagen phase in the control area and follicles in the telogen phase in the treated area demonstrates the efficiency of the laser at different wavelengths when reaching different skin phototypes and hair thickness, being reinforced by apoptosis and cell proliferation markers. Therefore, the hair-removal process has been optimized with various laser wavelengths.

Optimal Timing of Laser Hair Removal in Expanded Forehead Flap in the Reconstruction of Facial Defects: During or After Tissue Expansion?

Background: The optimal timing of laser epilation with expanded forehead flaps in facial defect reconstruction remains undetermined. Objective: To compare the efficacy and safety of hair removal during or after flap expansion. Methods: This prospective exploratory study included 15 (11 women and 4 men, 16.47 ± 16.331 years of age) and 26 (19 women and 7 men, 10.69 ± 10.899 years of age) patients who underwent 755 nm long-pulsed alexandrite laser epilation during flap expansion and after surgery, respectively. Facial reconstruction was performed in these patients because of congenital melanin nevus, scar or port-wine stains. Evaluation included hair reduction rate, patient satisfaction, and adverse events. Results: The median number of laser sessions for hair removal during flap expansion was significantly lower than that after surgery (2.00 vs. 3.00, p < 0.01), and the hair reduction rate was also significantly higher during flap expansion (79.5% ± 21.93% vs. 68.3% ± 17.44%, p < 0.05). No severe adverse events were reported. Conclusion: Laser hair removal is safe and efficient when performed both during flap expansion period and after surgery, but its efficacy was significantly higher, and fewer sessions were required when performed during tissue expansion. Clinical trial registration information: ChiCTR1900026090.

Adverse Events of Light-Assisted Hair Removal: An Updated Review

BACKGROUND

With light-assisted hair removal becoming widely used, reports of adverse effects are increasing.

OBJECTIVE

To review all the reported optical incidents and cutaneous complications of laser or intense pulse light-assisted hair removal.

METHODS

A PubMed database systematic search was performed to identify studies reporting such adverse events before July 2022 using the Mesh terms "adverse effects" AND "hair removal" AND ("laser" OR "intense pulse light").

RESULTS

Altogether, 358 references were identified. After excluding duplicates, unrelated articles, guidelines, and conference abstracts, then adding references from studies bibliography, 104 publications were included. Ocular incidents consisted of anterior uveitis, iritis and iris atrophy, pupillary distortion, posterior synechiae, anterior chamber pigment, and cataracts in the anterior subcapsular region. Cutaneous complications consisted of pain, burns, folliculitis, leukotrichia, paradoxical hypertrichosis, pigmentary changes, changes in nevi, pili bigemini, herpes infection, hyperhidrosis, bromhidrosis, Fox-Fordyce disease, and frostbite from the cooling system. They were mostly correlated to skin type and body area as well as to light device and set parameters. Intense pulse light devices were found to be less painful than alexandrite laser, yet more painful than diode laser; Nd:YAG laser had the highest pain score.

CONCLUSION

Optical incidents can be systematically avoided. Cutaneous complications are usually related to professional errors and patient characteristics. Better knowledge of laser physics and adequate training of laser operators are key recommendations to avoid undesirable side effects. Safety recommendations help prevent most of the reported complications.

Efficacy of Laser in Hair Removal: A Network Meta-analysis

BACKGROUND

Laser hair removal is an increasingly prevalent trend of cosmetic procedures. The purpose of this study was to assess the effectiveness of hair reduction among several types of laser interventions.

METHODS

The selected studies searched in PubMed and EMBASE were assessed for quality of evidence, and extracted data on absolute hair count and hair reduction rate. Qualitative data were synthesized using standardized mean difference (SMD) in frequentist network meta-analysis because various measurement units were used among selected studies. Inconsistency and small study effects were examined by design-by-treatment interaction model and comparison-adjusted funnel plot.

RESULTS

A total of 13 randomized controlled trials (RCTs) (n = 652) were contributed to network meta-analysis. Pooled results revealed that diode laser showed significantly lower absolute hair count within three-month (SMD = -13.21, 95% confidence interval [CI]: -22.25 to -4.17) and around six months follow-up (SMD = -11.01, 95% CI: -18.24 to -3.77) as compared with those in control group, but no significant difference among laser interventions. All side effects observed were transient without leaving any permanent scars.

CONCLUSION

Eliminating unwanted hair with lasers or intense pulsed light is safe and effective; however, which type of intervention is more beneficial in the long-term process should be studied with a longer follow-up time.

Mechanism of crescent-shaped and ring-shaped epidermal damage from laser hair removal with cryogen spray cooling

The safety and efficacy of laser hair removal have been well established through many clinical studies and through clinical use over the past 25 years. A laser hair removal device that protects the epidermis by utilizing cryogen spray cooling (CSC) is widely used internationally. In darker skin types, post-inflammatory hyperpigmentation (PIH) can occur after laser hair removal. In particular, laser hair removal with CSC is known to cause crescent-shaped or ring-shaped PIH. In this experiment, we report a visualization of this PIH mechanism. The laser used in this experiment is a 755-nm-long-pulsed alexandrite laser. Graph paper was treated with this laser to assess for thermal damage. We investigated changes in thermal damage due to differences in laser spot size, fluence output, and laser beam angle in relation to the graph paper. When using a spot size of 18 mm, we observed that higher fluences caused crescent-shaped thermal damage on the margins of the treated graph paper. It was also confirmed that when the hand piece is not held perpendicular to the skin, the laser-treated area is expanded and the CSC range is narrowed. These factors caused the area of thermal damage to widen. This widening causes ring-shaped thermal injury, leading to PIH. We treated graph paper using a hair removal laser with CSC to investigate the mechanism of crescent or ring-shaped thermal damage. Laser treatment on graph paper is effective as a test for defects in the CSC device. Factors that cause inadequate cooling, which leads to PIH, are large spot size, high fluence, not holding the laser hand piece perpendicular to the skin, and malfunctioning of CSC device.

Safety of Laser Hair Removal in Patients Receiving Systemic Isotretinoin for Acne Vulgaris

BACKGROUND

A few reports on scar and keloid formation in patients receiving systemic isotretinoin have encouraged a conservative approach in which laser procedures are delayed during and 6 to 12 months after the completion of treatment.

OBJECTIVE

To assess the safety of laser hair removal with alexandrite, diode, and Nd:YAG lasers in patients receiving systemic isotretinoin treatment.

MATERIALS AND METHODS

Fifty-two patients who underwent laser hair removal during isotretinoin treatment were retrospectively analyzed and compared with a control group for side effects.

RESULTS

There were 48 female and 4 male patients. The average isotretinoin dose was 33.7 mg/d. The average interval between the start of isotretinoin treatment and the first laser hair removal was 39.3 days. The mean number of sessions under treatment was 4.1. Three patients had temporary crusting, and 1 patient had a small area of temporary hypopigmentation. Five (9.6%) patients in the control group had crusting. The incidence of side effects was not significantly different between the 2 groups (p > .05). Neither patients in the isotretinoin group nor those in the control group experienced blistering, pigmentation, ulceration, and scar or keloid formation.

CONCLUSION

Laser hair removal is a safe procedure with alexandrite, diode, and Nd:YAG lasers in patients receiving systemic isotretinoin.

Paradoxical Hypertrichosis Associated with Laser and Light Therapy for Hair Removal: A Systematic Review and Meta-analysis

BACKGROUND

Paradoxical hypertrichosis (PH) is an uncommon, poorly understood adverse effect associated with laser or intense pulsed light treatment for hair removal.

OBJECTIVE

The objective of this study was to conduct a systematic review and meta-analysis to determine PH prevalence and associated risk factors.

METHODS

We conducted a systematic review and meta-analysis of studies evaluating hair removal with lasers or intense pulsed light. Primary outcome was PH prevalence. Meta-regression and subgroup analysis were used to investigate associations among treatment modality, patients' characteristics, and PH.

RESULTS

Included were 9733 patients in two randomized controlled trials and 20 cohort studies (three prospective and 17 retrospective). Pooled PH prevalence was 3% (95% confidence interval 1-6; I² = 97%). Paradoxical hypertrichosis was associated with a face or neck anatomic location, and occurred in only 0.08% of non-facial/neck cases. Treatment modality and interval between treatments had no effect on the PH rate. There were insufficient data to determine the association between sex and skin type to PH. In three out of four studies, PH gradually improved with continued therapy.

CONCLUSIONS

Based primarily on cohort studies, PH occurs in 3% of patients undergoing hair removal with lasers or intense pulsed light, yet rarely outside the facial/neck areas. Treatment modality does not seem to be a contributing factor. Continuation of treatment in areas with PH may be the most appropriate treatment.

Three wavelengths integrated: Efficacy and safety of a novel combination for hair removal

BACKGROUND

Laser hair removal is one of the most popular aesthetic procedures.

AIMS

The study aimed to assess the efficacy and safety of a novel applicator combining three wavelengths (1064 nm, 810 nm, and 755 nm) for hair removal.

PATIENTS/METHODS

This prospective study included a four-session hair removal treatment with three wavelengths combined and emitted simultaneously using an in-motion technique. Patients were treated in eight-week intervals between each session and a follow-up of 3 months.

RESULTS

Twenty-two men (mean age 41.5 years, SD = 6.1) were included: two (9.1%) Fitzpatrick skin type II, 19 (86.4%) type III, and one (4.5%) type IV. Treated areas were two abdomens (14%), fourteen backs (64%), and five thoraxes (23%). Hair characteristics were evaluated with a dermatoscopic imaging system. Three months after the last session, the mean decrease in the hair count was of 75.6% (SD 5.9) (p < 0.0001), in hair density of 75.6% (SD 5.9) (p < 0.0001), in the terminal hair number of 60.1% (SD 55.0) (p < 0.0001), and in the vellus hair number of 39.7% (SD 72.9) (p = 0.0001).

CONCLUSION

The combined three different wavelengths in a single device provided a wide range of absorption and penetration, allowing for a safe and effective treatment.

Reconceptualizing the permanence of alexandrite laser hair removal results: a long-term follow-up study

Background: The permanence of Alexandrite laser hair removal (LHR) has been of great interest. However, studies on long-term outcome are lacking.Objective: To evaluate the hair reduction rates (HRRs) and laser parameters of patients who no longer need epilation after LHR, and redefine permanence.Patients & Methods: Out of 183, 100 patients who discontinue epilation at least 2 years after LHR were included in the study. Self-perceived HRRs and patient satisfaction were recorded through patient questionnaires. The correlations between HRRs and treatment parameters, and the presence of polycystic ovary syndrome (PCOS) were assessed.Results: Treatment sites were the face, legs, trunk, arm and bikini regions. Twenty-one patients had PCOS. The means of results (in range) were as follows; HRRs [56.28% (±19.73) and 67.74% (±16.42)]; the session numbers [5.52 (±2.50) and 9.80 (±4.15)] and, the treatment durations [62.2 (±40.0) and 90.0 (±45.9) weeks]. All patients stated they no longer require epilation since the remaining hairs were too thin to be noticed.Conclusion: Our results demonstrate that, even in the presence of PCOS, hair reduction together with thinning satisfy patients without total removal of hairs. Therefore, the elimination of the need for epilation might be considered as the 'permanent result' of LHR.

Analysis of the Curative Effect of Alexandrite Laser in the Treatment of Venous Lake of Lips

BACKGROUND AND OBJECTIVES

Laser is being widely used in clinical treatment nowadays, including 755 nm Alexandrite laser [1,2]. This study was conducted to examine the clinical outcome of long-pulse 755 nm Alexandrite laser in the treatment of venous lake of the lip.

STUDY DESIGN/MATERIALS AND METHODS

Forty-one patients (2015-2019) were reviewed. The clinical outcomes were assessed 1 month after the treatment. The efficacy of the treatment was classified into four categories: basic recovery (most optimal outcome), effective, improvement, and ineffective (least favorable outcome). Adverse reactions were also recorded.

RESULTS

Thirty-three (80.49%) patients achieved basic recovery and 8 (19.51%) were effective; 29 (70.73%) recovered after receiving one treatment, 3 (7.32%) recovered after receiving two treatments, and 1 (2.44%) recovered after three treatments.

CONCLUSION

Long-pulse 755 nm Alexandrite laser is an effective treatment for the venous lake of the lip. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.