Treatment of Café-Au-Lait Spots Using Q-Switched Alexandrite Laser: Analysis of Clinical Characteristics of 471 Children in Mainland China

The Emerging Role of Visible Light in Melanocyte Biology and Skin Pigmentary Disorders: Friend or Foe?

Electromagnetic radiation, notably visible light (VL), has complicated effects on human skin, particularly pigmentation, which have been largely overlooked. In this review, we discuss the photobiological mechanisms, pathological effects, clinical applications and therapeutic strategies of VL at varying wavelengths on melanocyte biology and skin pigmentary disorders. Different VL wavelengths may impose positive or negative effects, depending on their interactions with specific chromophores, photoaging, ROS production, circadian rhythm and other photon-mediated reactions. Further in vivo and in vitro studies are required to establish the pathologic mechanisms and application principles of VL in pigmentary disorders, as well as optimal photoprotection with coverage against VL wavelengths.

Laser treatment for Cafe-au-lait Macules: a systematic review and meta-analysis

Nowadays, laser is the mainstay treatment for cafe-au-lait macules (CALMs), but no systematic review has been published to demonstrate the overall efficacy and it's still controversial which type of laser is optimal. Thus, we conduct the meta-analysis to evaluate the effectiveness and side effects of various types of lasers in treating CALMs. Original articles reporting the efficacy and side effects for CALMs in laser treatment were identified in PubMed, EMBASE, and Web of Science from 1983 to April 11, 2023. Using R software and the 'meta' package, meta-analysis was conducted for clearance and recurrence for evaluation of efficacy. And the occurrence of hypopigmentation and hyperpigmentation rate was pooled for safety evaluation. We used RoB2 and ROBINS-I tools to assess the risks of bias in RCT studies and non-RCT studies, respectively. The Grading of Recommendations, Assessment, Development and Evaluation system was used to assess the quality of the evidence. Nineteen studies involving 991 patients were included, which had a very low to moderate quality of evidence. The pooled 75% clearance rate was 43.3% (95% CI 31.8-54.7%, I² = 96%), 50% clearance rate was 75% (95% CI 62.2-85.9%, I² = 89%) and the recurrence rate was 13% (95% CI 3.2-26.5%, I² = 88%). The pooled hypopigmentation and hyperpigmentation rates were 1.2% (95% CI 0.3-2.1%, I² = 0%) and 1.2% (95% CI 0.3-2%, I² = 0%), respectively. Subgroup analysis revealed that QS-1064-nm Nd:YAG laser treatment not only achieved more than 75% clearance rate in 50.9% of patients (95% CI 26.9-74.4%, I² = 90%) but also resulted in the lowest hypopigmentation and hyperpigmentation rate of 0.5% (95% CI 0.0-2.5%, I² = 26%) and 0.4% (95% CI 0.0-2.5%, I² = 0%). To draw a conclusion, the laser treatment could reach an overall clearance rate of 50% for 75% of the patients with CALMs, for 43.3% of the patients, the clearance rate could reach 75%. When looking at different wavelength subgroups, QS-1064-nm Nd:YAG laser exhibited the best treatment capability. Laser of all the wavelength subgroups presented acceptable safety regarding of the low occurrence of side effects, namely, hypopigmentation and hyperpigmentation.

Comparison of the safety and efficacy of low fluence Q-switched 1064-nm and conventional Q-Switched 755-nm lasers in the treatment of café-au-lait macules: A prospective self-controlled trial

BACKGROUND

Conventional high fluence Q-switched (HFQS) Alexandrite 755-nm are widely used in clinical café-au-lait macules (CALMs) treatment. There have been recent concerns regarding the efficacy and safety of low fluence Q-switched (LFQS) Nd: YAG 1064-nm lasers.

OBJECTIVE

To evaluate the efficacy and safety of the conventional HFQS and LFQS laser in the treatment of CALMs.

METHODS

Within 3 months, 20 patients underwent prospective self-controlled split-lesion treatments with HFQS once or twice depending on the recovery rate, and with LFQS six times biweekly. Then the more effective laser was selected for continued treatments. Efficacy outcomes were evaluated by a visual analog scale (VAS) biweekly during the comparative trail. Recovery process, side effects and recurrence were recorded during the trial and follow-up visit. Patient and physician preferences for laser selection were also recorded.

RESULTS

The average VAS scores of areas treated with HFQS and LFQS were 2.92 ± 0.86 and 2.93 ± 1.13, respectively (p > 0.05). The most significant efficacy change of LFQS was after the fourth laser treatment (VAS score: 1.82-2.37, p < 0.001). 11 lesions treated with LFQS and 7 with HFQS achieved an optimal treatment response (3.67 ≤ VAS ≤ 4). Three patients relapsed on one side (one on LFQS, two on HFQS) and five on both sides. Adverse effects included temporary hypopigmentation, hyperpigmentation, uneven pigmentation, and mottled hypopigmentation. Doctors thought 80% of patients were suitable for LFQS. 70% of patients preferred LFQS posttreatment.

CONCLUSIONS

The efficacy difference between the LFQS 1064-nm laser and HFQS 755-nm laser in treating CALMs in a 3-month comparative trial was statistically insignificant. LFQS is preferred by doctors and patients and is likely to help more patients achieve treatment efficacy than the HFQS within a short time, with fewer temporary adverse reactions, and a more even pigmentation. But it can cause mottled hypopigmentation. The LFQS had obvious lesion clearance after the fourth treatment.

Laser treatment of benign melanocytic lesion: a review

Treatment of pigmented lesions is one of the major challenges of laser and cosmetic practitioners. The most common pigmented lesions that are treated by lasers are melanocytic nevi, ephelides, solar lentigines, and café au lait macules. Melanin absorbs different wavelengths (500-1100 nm); thereby, treatment of various pigmented lesions requires the application of lasers with different wavelengths. Choosing the most appropriate type of laser depends on various factors such as the chromophore and the location of a specific lesion in the skin. In this paper, we aim to review the most efficient laser treatment protocols for each pigmented skin lesion and compare their efficacy in each part based on the previous studies.

Use of Reflectance Confocal Microscopy to Predict Treatment Efficacy in Café Au Lait Macules

BACKGROUND

Multiple lasers have been used for the treatment of café au lait macules (CALMs) with various results. Objective tools to predict therapeutic efficacy of CALMs treatment is lacking.

OBJECTIVE

To determine whether reflectance confocal microscopy (RCM) characteristics correlate with CALMs response to laser treatment.

MATERIALS AND METHODS

All CAMLs underwent RCM examination of length and density of dermal papillae followed by 3 sessions of Q-switched alexandrite laser (QSAL). A visual analog scale was used to assess clinical treatment efficacy.

RESULTS

Forty-three patients were included, 22 had CALMs with irregular borders and 21 with smooth borders. Café au lait macules with irregular border had shorter rete pegs and less papillae (p < .05) on RCM compared with smooth border CAMLs and responded better to QSAL treatment (2.32 vs 1.10).

CONCLUSION

Reflectance confocal microscopy measurement of length and density of papillae were inversely correlated with treatment response. Reflectance confocal microscopy may be a useful tool to predict CALMs response to laser treatment.

Comparative Effectiveness of 755-nm Picosecond Laser, 755- and 532-nm Nanosecond Lasers for Treatment of Café-au-Lait Macules (CALMs): A Randomized, Split-Lesion Clinical Trial

BACKGROUND AND OBJECTIVES

Many types of lasers have been used to treat café-au-lait macules (CALMs) since the introduction of the selective photothermolysis theory. However, the efficacy and safety of picosecond lasers, compared with those of nanosecond lasers, have not been researched. To compare the efficacy and safety of 755 nm picosecond laser (PS-755 nm), Q-switched (QS) Alexandrite 755 nm nanosecond laser (QS-755 nm), and QS Nd:YAG 532 nm nanosecond laser (QS-532 nm) for treating CALMs.

STUDY DESIGN/MATERIALS AND METHODS

Forty-one patients received several treatments at 3-month intervals. Lesions were divided into two or three approximately equal parts, which were randomly treated with PS-755 nm, QS-755 nm, and QS-532 nm. The safety and efficacy of three lasers were determined based on blinded visual assessments and self-reports of patients three months after the comparative trial.

RESULTS

Visual assessment 3 months after the comparative trial revealed that there was no statistically significant difference among the sites treated by QS-755 nm (2.84 ± 1.11), QS-532 nm (2.63 ± 1.06), and PS-755 nm (2.74 ± 1.05) lasers. Five (26.32%) of 19 patients showed lesion recurrence. Adverse effects included acneiform miliaris, hypopigmentation, and hyperpigmentation, which were resolved within 12 months. Five (26.32%) of 19 patients who showed lesion recurrence 1-5 months after laser treatment had lightened or cleared at least 50% of the lesion. 46.67% of patients were satisfied or very satisfied with the outcome of the overall treatment.

CONCLUSIONS

PS-755 nm, QS-755 nm, and QS-532 nm laser treatments were equally effective in treating and improving CALMs. PS-755 nm caused fewer adverse effects. Individuals can react differently to different types of lasers. Patch tests should be conducted before the treatment. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.