Photoepilation with a diode laser vs. intense pulsed light: a randomized, intrapatient left-to-right trial

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.

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.

Comparison of Two Surgical Epilation Procedures Based on the Nagata Method in All Degrees of Low Hairline Microtia

Background: Various methods exist to manage unwanted hair in low hairline microtia. We present our 10-year experience that compares the two procedures toward all degrees of low hairline microtia. Methods: The tongue-shaped split-thickness skin graft procedure (modified Chen's procedure) and the modified Nagata procedure were used for ear reconstruction in 42 microtia patients with three degrees of low hairlines from 2010 to 2020. Hair follicles in the low hairline area were removed free-hand, and the removed area was replaced with extended temporoparietal fascia (TPF) flap during the ear elevation. The satisfaction score and the clearance percentages of the hair were used as outcome measures. Results: There was no significant difference in satisfaction scores and the hair clearance percentages of hair between two procedures (p > 0.05) and among three degrees of low hairline (p > 0.05), respectively. Although the complication rate showed no significant difference, the major types of complication in modified Chen's procedure was fluid accumulation (9.52%), whereas in modified Nagata procedure was hypertrophic scar (4.76%). Conclusion: Patients with low hairlines can be treated using two different microtia reconstruction techniques to limit hair growth on the new ear. The rib graft construct is covered by a TPF flap, which is then grafted with an ultrathin skin graft and shows benefit in this review of our 10-year experience. Clinical Trial Registration Information Provided: Registration no. and date registered: ChiCTR2000030214.

Plasmon-Based Biofilm Inhibition on Surgical Implants

The insertion of an implant in the body of a patient raises the risk of a posterior infection and formation of a biofilm, which can have critical consequences on the patient's health and be associated with a high sanitary cost. While antibacterial agents can be used to prevent the infection, such a strategy is time-limited and causes bacteria resistance. As an alternative to biochemical approaches, we propose here to use light-induced local hyperthermia with plasmonic nanoparticles. This strategy is implemented on surgical meshes, extensively used in the context of hernia repairing, one of the most common general surgeries. Surgical meshes were homogeneously coated with gold nanorods designed to efficiently convert near-infrared light into heat. The modified mesh was exposed to a biofilm of Staphylococcus aureus ( S. aureus) bacteria before being treated with a train of light pulses. We systematically study how the illumination parameters, namely fluence, peak intensity and pulse length, influence the elimination of attached bacteria. Additionally, fluorescence confocal microscopy provides us some insight on the mechanism involved in the degradation of the biofilm. This proof-of-principle study opens a new set of opportunities for the development of novel disinfection approaches combining light and nanotechnology.

Photoepilation and Skin Photorejuvenation: An Update

The effectiveness of intense pulsed light (IPL) and laser devices is widely accepted in aesthetic dermatology for unwanted hair removal and treatment of a variety of cutaneous conditions. Overall, most comparative trials have demonstrated similar effectiveness for IPL and laser devices. Literature studies alternatively favor the IPL and laser concepts, but the incidence of severe local pain and side effects were generally lower with IPL. IPL phototherapy, already established as a sound option in photoepilation and treatment of photoaging, hyperpigmentation and other skin conditions, is also considered first choice in the phototherapy of skin vascular malformations. When treating large areas, as often required in photoepilation and many aesthetic dermatology indications, IPL technologies show advantages over laser-based devices because of their high skin coverage rate. Compared to lasers, the wide range of selectable treatment settings, though a strong advantage of IPL, may also imply some more risk of local thermal side effects, but almost only in the hands of poorly trained operators. Overall, the strongest advantages of the IPL technologies are robust technology, versatility, lower purchase price, and the negligible risk of serious adverse effects in the hands of skilled and experienced operators.

Side effects from intense pulsed light: Importance of skin pigmentation, fluence level and ultraviolet radiation-A randomized controlled trial

BACKGROUND AND OBJECTIVE

Intense pulsed light (IPL) is a mainstream treatment for hair removal. Side effects after IPL are known, but risk factors remain to be investigated. The objective of this study was to assess the contribution of skin pigmentation, fluence level, and ultraviolet radiation (UVR) on IPL-induced side effects.

METHODS

The study was a blinded, randomized intra-individual controlled trial including 16 healthy subjects with Fitzpatrick Skin Types (FST) II-V. Three test areas were each divided into four sites, randomized to a single IPL exposure of 22, 34, 46 J/cm² or triple stacking of 46 J/cm² . Areas were subsequently randomized to no UVR or single solar-simulated UVR exposure of 3 Standard Erythema Dose at 30 minutes or 24 hours after IPL. Each area had a corresponding control, resulting in 15 treatment sites. Follow-up visits were scheduled up to 4 weeks after IPL. Outcome measures were: (i) blinded clinical skin reactions; (ii) objectively measured erythema and pigmentation; (iii) pain measured by visual analog scale (VAS); (iv) histology (H&E, Fontana-Masson); and (v) mRNA-expression of p53.

RESULTS

Fifteen subjects with FST II-IV completed the protocol. IPL induced a wide range of skin reactions, including erythema (87% of subjects), purpura (27%), blisters (20%), edema (13%), crusting (13%), hyper- (60%), and hypopigmentation (20%). Darker skin pigmentation and increasing IPL fluence were determinants for IPL-induced side effects (P ≤ 0.002), while a single exposure of UVR did not exacerbate side effects (P ≥ 0.180). Clinical findings were confirmed objectively by reflectance spectrometry and qualitatively by histological changes in skin architecture, inflammatory infiltration, and pigmentation. Marker of cellular DNA damage, that is, p53, did not increase after IPL (P ≥ 0.24).

CONCLUSIONS

Skin pigmentation and IPL fluence are major determinants of side effects after IPL exposure, while a single exposure to three SED of UVR at 30 minutes or 24 hours after IPL, does not amplify such side effects. Lasers Surg. Med. 49:88-96, 2017. © 2016 Wiley Periodicals, Inc.

Near Infrared Pulsed Light for Permanent Hair Reduction in Fitzpatrick Skin Types IV and V

Background:

Excessive hair on the face is a significant cause for distress amongst women. Permanent hair reduction methods including lasers and pulsed light devices are increasingly being used.

Aims:

The aim of this study is to evaluate the efficacy and safety of near infrared pulsed light source for permanent hair reduction in women seeking treatment for excessive hair growth on the upper lip and chin.

Settings and Design:

This was a prospective observational study done at a tertiary care hospital in South India.

Materials and Methods:

Women above 18 years of age were observed for six sittings of the treatment for excessive hair over the upper lip and chin using a near infrared intense pulsed light device. Efficacy was evaluated by measuring percentage hair reduction using digital photography. Further, efficacy amongst women with polycystic ovarian syndrome (PCOS) was compared with those without PCOS. Side effects were noted.

Statistical Analysis Used:

Student's unpaired t-test using the software SPSS version 16.

Results:

Percentage hair reduction at the end of 6 sittings in 24 women for the upper lip and chin was 52.87% and 73.81%, respectively. Out of the 24 women, 12 had PCOS and the difference in hair reduction in these women was statistically insignificant when compared to that observed in those without PCOS. Only two patients experienced side effects in the form of mild pain and discomfort.

Conclusions:

Intense pulsed light is a safe and efficacious tool for permanent hair reduction over the upper lip and chin, efficacy being similar in patients with or without PCOS.

Efficacy and Safety of Hair Removal with a Long-Pulsed Diode Laser Depending on the Spot Size: A Randomized, Evaluators-Blinded, Left-Right Study

BACKGROUND

The efficacy of the long-pulsed diode laser (LPDL) in hair removal is determined with various physical parameters. Recently, LPDLs with a larger spot size are commercially available; however, the independent effect of spot size on hair removal has not been studied.

OBJECTIVE

This study aimed to compare the efficacy of the LPDL in hair removal depending on the spot size.

METHODS

A randomized, evaluators-blind, intrapatient comparison (left vs. right) trial was designed. Ten healthy Korean women received three hair removal treatment sessions on both armpits with the 805-nm LPDL and followed for 3 months. A 10×10 mm handpiece (D1) or a 10×30 mm handpiece (D3) was randomly assigned to the right or left axilla. The fluence, pulse duration, and epidermal cooling temperature were identical for both armpits. Hair clearance was quantified with high-resolution photos taken at each visit. Postprocedural pain was quantified on a visual analogue scale. Adverse events were evaluated by physical examination and the patients' self-report.

RESULTS

The mean hair clearance at 3 months after three treatment sessions was 38.7% and 50.1% on the armpits treated with D1 and D3, respectively (p=0.028). Procedural pain was significantly greater in the side treated with D3 (p=0.009). Serious adverse events were not observed.

CONCLUSION

Given that the pulse duration, fluence, and epidermal cooling were identical, the 805-nm LPDL at the three times larger spot size showed an efficacy improvement of 29.5% in axillary hair removal without serious adverse events.

Fixed, low radiant exposure vs. incremental radiant exposure approach for diode laser hair reduction: a randomized, split axilla, comparative single-blinded trial

BACKGROUND

Diode lasers are the most commonly used treatment modalities for unwanted hair reduction. Only a few controlled clinical trials but not a single randomized controlled trial (RCT) compared the impact of various laser parameters, especially radiant exposure, onto efficacy, tolerability and safety of laser hair reduction.

OBJECTIVE

To compare the safety, tolerability and mid-term efficacy of fixed, low and incremental radiant exposures of diode lasers (800 nm) for axillary hair removal, we conducted an intrapatient, left-to-right, patient- and assessor-blinded and controlled trial.

METHODS

Diode laser (800 nm) treatments were evaluated in 39 study participants (skin type II-III) with unwanted axillary hairs. Randomization and allocation to split axilla treatments were carried out by a web-based randomization tool. Six treatments were performed at 4- to 6-week intervals with study subjects blinded to the type of treatment. Final assessment of hair reduction was conducted 6 months after the last treatment by means of blinded 4-point clinical scale using photographs. The primary endpoint was reduction in hair growth, and secondary endpoints were patient-rated tolerability and satisfaction with the treatment, treatment-related pain and adverse effects.

RESULTS

Excellent reduction in axillary hairs (≥ 76%) at 6-month follow-up visit after receiving fixed, low and incremental radiant exposure diode laser treatments was obtained in 59% and 67% of study participants respectively (Z value: 1.342, P = 0.180). Patients reported lower visual analogue scale (VAS) pain score on the fixed (4.26) than on the incremental radiant exposure side (5.64) (P < 0.0003). The only side-effect was mild and transient erythema. Subjects better tolerated the fixed, low radiant exposure protocol (P = 0.03). The majority of the study participants were satisfied with both treatments.

CONCLUSION

Both low and incremental radiant exposures produced similar hair reduction and high and comparable patient satisfaction. However, low radiant exposure diode laser treatments were less painful and better tolerated.

Statistical reporting in randomized controlled trials from the dermatology literature: a review of 44 dermatology journals

BACKGROUND

The validity of randomized controlled trials (RCTs) is determined by several statistical factors.

OBJECTIVES

To determine the level of recent statistical reporting in RCTs from the dermatology literature.

METHODS

We searched MEDLINE for all RCTs published between 1 May 2013 and 1 May 2014 in 44 dermatology journals.

RESULTS

Two hundred and ten articles were screened, of which 181 RCTs from 27 journals were reviewed. Primary study outcomes were met in 122 (67.4%) studies. Sample size calculations and beta values were reported in 52 (28.7%) and 48 (26.5%) studies, respectively, and nonsignificant findings were supported in only 31 (17.1%). Alpha values were reported in 131 (72.4%) of studies with 45 (24.9%) having two-sided P-values, although adjustment for multiple statistical tests was performed in only 16 (9.9% of studies with ≥ two statistical tests performed). Sample size calculations were performed based on a single outcome in 44 (86.3%) and multiple outcomes in six (11.8%) studies. However, among studies that were powered for a single primary outcome, 20 (45.5%) made conclusions based on multiple primary outcomes. Twenty-one (41.2%) studies relied on secondary/unspecified outcomes. There were no differences for primary outcome being met (Chi-square, P = 0.29), sample size calculations (P ≥ 0.55), beta values (P = 0.89), alpha values (P = 0.65), correction for multiple statistical testing (P = 0.59), two-sided alpha (P = 0.64), support of nonsignificant findings (Fisher's exact, P = 0.23) based on the journal's impact factor.

CONCLUSIONS

Levels of statistical reporting are low in RCTs from the dermatology literature. Future work is needed to improve these levels of reporting.