Influence of the frequency of laser toning for melasma on occurrence of leukoderma and its early detection by ultraviolet imaging

Cosmetic Considerations in Dark-Skinned Patients

For dermatologists, diversities of human races result in an opportunity to encounter patients with various skin types. Cosmetic procedures have gained more popularity and become more accessible over the past decades. Thus, the selection of appropriate treatment protocol for each patient becomes inevitable. This review will focus on basic knowledge and key points in performing safe cosmetic-related procedures in patients with dark-complexioned skin. In terms of structure and function of the skin, people of color have equal epidermal thickness, corneocyte size and melanocyte number. However, they have more stratum corneum compaction, melanosome dispersion and melanocyte activity than fair skin individuals. Data regarding drug penetration and cutaneous irritation showed conflicting results. Superficial chemical peels and microdermabrasion can be done safely in dark-skinned patients. Medium-depth peel should be used with extreme caution. While deep-depth peel should be avoided at all times due to pigmentary and textural complications. Prolonged treatment interval, use of priming agents and sun protection are recommended. Injectable materials including botulinum toxin and soft tissue augmentation by hyaluronic acid filler can be done harmlessly in dark-skinned patients. Lasers and energy-based devices should be done with caution. Higher melanin dispersion and melanocyte activity acts as competitive chromophore. Pigmentary or textural changes can occur after aggressive treatment protocol. High energy setting, pulse stacking, short wavelength lasers and short treatment interval should be avoided in dark-skinned patients.

Efficacy and Safety of Low Fluence Nd:YAG Laser Treatment in Melasma: A Meta-Analysis and Systematic Review

BACKGROUND

Low-fluence, multisession therapy of Nd:YAG laser has been widely used for treating melasma.

OBJECTIVE

To evaluate the efficacy and safety of low-fluence Nd:YAG laser toning for melasma using a systematic review and meta-analysis.

METHODS

The PubMed, Web of Science, Embase, and Cochrane Library databases were searched till December 2020. A total of 50 studies (1,772 patients) and 66 studies were selected for the evaluation of the efficacy and complications, retrospectively.

RESULTS

The mean Melasma Area and Severity Index/modified Melasma Area and Severity Index scores for laser toning as monotherapy at <4, 4 to <8, 8 to <12, 12 to <24, and ≥24 weeks after treatment compared with that at pretreatment were -0.51, -0.91, -0.97, -0.92, 0.01 SD, whereas those as combination therapy were -1.64, -1.26, -0.94, not available, -1.45 SD, respectively. An increase in light value and a decrease in relative lightness index have remained up to 8 weeks after laser toning. Complications including hypopigmentation/leukoderma, postinflammatory hyperpigmentation, and recurrence were noted. The incidence of hypopigmentation/leukoderma correlated with the number of laser sessions (p = .036).

CONCLUSION

Low-fluence Nd:YAG laser toning as combination therapy has shown better efficacy than monotherapy and the efficacy seems to diminish with time. This study suggests the positive correlation of hypopigmentation/leukoderma with the number of laser sessions.

Combining Low Power Fractional CO2 With QS-NdYAG Toning in the Treatment of Melasma Reduces the Incidence of Punctate Leukoderma

BACKGROUND AND OBJECTIVES

Q-switched Nd:YAG (QS-Nd:YAG) toning (low fluence, large spot size, and high frequency) has been used successfully for the treatment of melasma, especially in dark skin phototypes. Punctate leukoderma was found to be a frequent complication that reduced the safety of this procedure. Combining low power fractional CO₂ laser, which is another effective melasma laser therapy, might improve the efficacy and safety of this procedure. The aim of this study was to evaluate  the effect of combining low power fractional CO₂ laser with QS-Nd:YAG toning in the treatment of melasma.

STUDY DESIGN/MATERIALS AND METHODS

A randomized comparative split-face study included a total of 30 patients with bilateral, symmetrical melasma. All patients received QS-Nd:YAG toning on one randomly selected side of the face, while the other side randomly received either low power fractional CO₂ alone (group A) or combined QS-Nd:YAG toning with low power fractional CO₂ (group B). QS-Nd:YAG toning sessions were scheduled every two weeks for nine consecutive sessions, and low power fractional CO₂ sessions were received every 4 weeks for three consecutive sessions. The assessment was done using the modified melasma area and severity index (mMASI) score, spectrophotometry (melanin index [MI] and erythema index [EI]), photography, blinded physician assessment, and patient satisfaction (at baseline, 1 week and 8-12 weeks after the last treatment sessions).

RESULTS

A significant reduction in the mMASI score and MI was obtained with all treatment regimens. On comparing different modalities, group A reduction in mMASI and MI was significantly greater on the side receiving QS-ND:YAG toning (64.03% and 8.27%, respectively), than the side receiving low power fractional CO₂ laser alone (36.02%. 2.64%, respectively). On the other hand, reduction of mMASI score and MI showed no statistical significance between the side receiving QS-Nd:YAG toning alone and the combined modality. Punctate leukoderma occurred in four cases (13%) on the side receiving QS-Nd:YAG toning.

CONCLUSION

QS-Nd:YAG toning is significantly more effective than low power fractional CO₂ in the treatment of melasma when used separately. Although combining low power fractional CO₂ with QS-Nd:YAG toning does not increase its efficacy, it minimizes the incidence of the undesirable punctate leukoderma complication and achieves lower recurrence. This combination can thus be recommended as a safe and effective measure for the treatment of melasma. © 2021 Wiley Periodicals LLC.

Evaluating the Risk Factors of Post Inflammatory Hyperpigmentation Complications with Nd-YAG Laser Toning Using LASSO-Based Algorithm

The neodymium-doped yttrium aluminum garnet (Nd-YAG) laser is used for removal of pigmented skin patches and rejuvenation of skin. However, complications such as hyperpigmentation, hypopigmentation, and petechiae can occur after frequent treatments. Therefore, identifying the risk factors for such complications is important. The development of a multivariable logistic regression model with least absolute shrinkage and selection operator (LASSO) is needed to provide valid predictions about the incidence of post inflammatory hyperpigmentation complication probability (PIHCP) among patients treated with Nd-YAG laser toning. A total of 125 female patients undergoing laser toning therapy between January 2014 and January 2016 were examined for post-inflammatory hyperpigmentation (PIH) complications. Factor analysis was performed using 15 potential predictive risk factors of PIH determined by a physician. The LASSO algorithm with cross-validation was used to select the optimal number of predictive risk factors from the potential factors for a multivariate logistic regression PIH complication model. The optimal number of predictive risk factors for the model was five: immediate endpoints of laser (IEL), α-hydroxy acid (AHA) peels, Fitzpatrick skin phototype (FSPT), acne, and melasma. The area under the receiver operating characteristic curve (AUC) was 0.79 (95% CI, 0.70–0.88) in the optimal model. The overall performance of the LASSO-based PIHCP model was satisfactory based on the AUC, Omnibus, Nagelkerke R2, and Hosmer–Lemeshow tests. This predictive risk factor model is useful to further optimize laser toning treatment related to PIH. The LASSO-based PIHCP model could be useful for decision-making.

Q-PTP is an optimized technology of 1064-nm Q-switched neodymium-doped yttrium aluminum garnet laser in the laser therapy of melasma: A prospective split-face study

Quickly-pulse-to-pulse (Q-PTP) is the latest dual pulse mode Q-switched neodymium-doped yttrium aluminum garnet [QS Nd:YAG (QSNY)] laser technology that improves efficacy and minimizes side effects. In this study, the safety, efficacy, and advantages of Q-PTP and single-pulse laser mode of 1064-nm QSNY in the treatment of melasma were compared. Twelve healthy women were enrolled in this split-face study. Q-PTP and single-pulse laser mode of 1064-nm QSNY were applied to the treatment side and the control side, respectively. Physician's global assessment, patients' self-assessment and the modified melasma area and severity index (mMASI) scores were used to quantify pigmentation changes. Side effects were recorded. Mean mMASI scores were decreased significantly at the 4th and 12th-week follow-up visit compared to the baseline. Melasma lesion clearance was more than 50% in 58% of patients compared with the baseline. However, both sides of the same patient showed similar therapeutic effect. Minor pain experience and slighter skin erythema reaction were reported in Q-PTP laser mode treatment side compared with the control. No serious complications were found in any of the patients. Q-PTP laser mode of 1064-nm QSNY is an optimal laser therapy in the treatment of melasma with greater safety and superiority.

Laser Toning in Melasma

Melasma is a common acquired disorder of hyperpigmentation. A variety of treatment options has been suggested for the management of melasma. A range of different lasers had been tried in the treatment of melasma. Q-switched Nd-YAG laser (QSL) is the most commonly used laser in the treatment of melasma. Recently, laser toning or low-fluence, multi-pass technique has become popular in treatment of melasma. Authors aimed to review the procedure, its effectiveness, combination therapies using laser toning, and complications of laser toning. A PubMed search was made using keywords such as laser toning, QSL, melasma, and lasers in melasma, and relevant articles were reviewed.

The Management of Melasma on Skin Types V and VI Using Light Emitting Diode Treatment

OBJECTIVE

This study investigated light emitting diode (LED) treatment for patients with melasma on darker skin types.

BACKGROUND

Melasma is a common disfiguring skin condition in women which is difficult to treat and is refractory. The cause of melasma remains unclear.

METHODS

In this study, 60 female participants aged between 25 and 60 years, who presented with melasma, were enrolled (n = 39.85). They were purposely assigned to two groups according to their skin types. Both groups received a total of 36 LED light treatments over a period of 9 months.

RESULTS

Both subjective and objective results indicated a significant improvement of melasma. Statistical analyses revealed significant improvements in both groups.

CONCLUSIONS

The results of this study suggest that LED is effective in managing melasma. These results will provide a basis for future therapeutic use of phototherapy to improve melasma.

Acquired disorders with hypopigmentation: A clinical approach to diagnosis and treatment

Acquired hypopigmented skin changes are commonly encountered by dermatologists. Although hypopigmentation is often asymptomatic and benign, occasional serious and disabling conditions present with cutaneous hypopigmentation. A thorough history and physical examination, centered on disease distribution and morphologic findings, can aid in delineating the causes of acquired hypopigmented disorders. The second article in this 2-part continuing medical education series focuses on conditions with a hypopigmented phenotype. Early diagnosis and appropriate management of these disorders can improve a patient's quality of life, halt disease progression, and prevent irreversible disability.

Epidermal grafting for leukoderma resulting from 1064-nm quality-switched neodymium-doped yttrium aluminium garnet laser toning

Leukoderma secondary to Q-switched 1064-nm neodymium-doped yttrium aluminium garnet laser is usually refractory to treatment. The pathogenesis was cumulative phototoxic damage to melanocytes and eventually resulted in melanocytopenia. Wood's light or UV imaging can help observe early leukoderma before it becomes apparent clinically and determine the degree of melanocytopenia before conducting a biopsy. NB-UVB phototherapy and 308-nm excimer laser can potentially worsen the pre-existing melasma lesions and may not be effective if the lesions have already become melanocytopenic. Epidermal grafting can replenish the hypopigmented area with melanocytes without worsening melasma.

Treatment of Laser Therapy-Induced Punctate Leukoderma Using a 308-nm Excimer Laser

Punctate leukoderma presents as numerous, distinct, round or oval depigmented spots. Recently, laser therapy-induced punctate leukoderma associated with various Q-switched laser and carbon dioxide laser have been reported. A 25-year-old man presented with numerous, discrete, round, confetti-like, depigmented macules on his left neck. He had undergone 3 sessions of 532-nm Q-switched Neodymium: Yttrium-Aluminum-Garnet laser treatment for café-au-lait macules three years ago. After the last laser treatment session, the punctate leukoderma had been developed. We started treatment with the 308-nm excimer laser twice a week. After 7 months of treatment duration, complete repigmentation was achieved without serious adverse effects. We recommend the 308-nm excimer laser as an effective treatment modality for laser therapy-induced punctate leukoderma.

Beneficial Effect of Low Fluence 1,064 nm Q-Switched Neodymium:Yttrium-Aluminum-Garnet Laser in the Treatment of Senile Lentigo

Background

Low fluence 1,064 nm Q-switched (QS) Neodymium:Yttrium-Aluminum-Garnet (Nd:YAG) laser treatment, also known as laser toning, is widely used for pigmentary disorders. There has been no reliable evaluation of the effect of low fluence 1,064 nm QS Nd:YAG laser for senile lentigo.

Objective

To investigate the beneficial effect of low fluence 1,064 nm QS Nd:YAG laser in the treatment of senile lentigo on the face.

Methods

A retrospective review was conducted on patients treated only with repetitive low fluence 1,064 nm QS Nd:YAG laser. Among them, 12 patients with multiple senile lentigines before treatment were included. All side effects were recorded to assess the safety of the modality.

Results

Mean age was 56.1±7.8 years old and male-to-female ratio was 1:11. Mean treatment fluence was 1.62±0.16 J/cm² and mean total treatment session was 8.8±2.6. Mean interval period between each session was 28.0±11.4 days and mean treatment session to reach marked and near total improvement was 8.7±2.8. At the final visit, seven of 12 (58.3%) patients reached marked and near total improvement, and three of 12 (25.0%) reached moderate improvement. No side effects occurred.

Conclusion

Repetitive low fluence 1,064 nm QS Nd:YAG laser treatment may be an effective and safe optional modality for senile lentigo.

Comparative study of dual-pulsed 1064 nm Q-switched Nd:YAG laser and single-pulsed 1064 nm Q-switched Nd:YAG laser by using zebrafish model and prospective split-face analysis of facial melasma

BACKGROUND

Recently dual-pulsed low-fluence 1064-nm Q-switched Nd:YAG (QSNY) laser has been developed for reducing complication during melasma treatment.

OBJECTIVE

Comparison of the efficacy and safety between dual-pulsed mode and single-pulsed mode for the treatment of melasma.

MATERIALS AND METHODS

In preclinical study, adult zebrafish were irradiated with dual-pulsed and single-pulsed mode. Changes of melanophore and cell death were assessed. In split-face clinical study, dual-pulsed and single-pulsed mode were irradiated on the left and right side of the face, respectively. L* value, clinical digital photos, modified Melasma Area and Severity Index (MASI) scores, and side effects were measured.

RESULTS

As compared to single-pulsed mode and dual-pulsed mode with longer intervals, zebrafish melanophore was cleared quickly at dual-pulsed mode with 80-μsec interval and 0.3 J/cm² fluence. Dual-pulsed mode showed the least regeneration of melanophore at 4 weeks after irradiation and no cell death was observed with 80-μsec interval. Both pulse modes improved melasma significantly but modified MASI score and L* value were not significantly different between each other. Lesser pain and shorter duration of post-laser erythema were observed with dual-pulsed mode.

CONCLUSION

Dual-pulsed mode was as effective as single-pulsed mode for the treatment of melasma and revealed less side effects.