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.

Australian experience and practical approach to the 308-nm excimer light therapy in dermatology.

The monochromatic excimer light therapy (308-nm excimer laser and lamp) is used to treat focal dermatoses with inflammation or hypopigmentation. In Australia, despite excimer light therapy being a proven effective treatment for many cutaneous conditions, barriers such as access and affordability provide considerable limitations to patients. This study aims to retrospectively evaluate the different applications of excimer light therapy in treating dermatologic conditions within the Australian setting and provide practical information for its use.

Hypopigmented Mycosis Fungoides: A Clinical and Histopathology Analysis in 9 Children.

BACKGROUND: Hypopigmented mycosis fungoides (HMF) is an uncommon variant of mycosis fungoides. AIMS: To study the clinical and histopathology presentation in children with HMF. METHOD: We reviewed 9 children diagnosed with HMF. The clinical data were collected and analyzed. RESULT: Eight boys and 1 girl were included, with a median onset age of 7.4 year old and median age of diagnosis of 10.5 year old. Multiple hypopigmented patches were observed in all patients, and 5 patients exhibited multiple scaly erythema at the center of hypopigmented patches. Histopathology showed atypical lymphocytes with hyperchromatic, irregular, and cerebriform nuclei, infiltrated in the epidermis and dermis. Pautrier's microabscesses was noted in 6 of 9 patients, and papillary dermal fibroplasia was noted in 6 of 9 patients. CD8 predominance was detected in 4 of 6 patients. Four patients were simultaneously subjected to skin biopsy on hypopigmented patches and scaly erythema simultaneously. Compared with hypopigmented specimens, erythema biopsy detected deeper and denser infiltration of atypical lymphoid cells in 3 of 4 patients, higher CD4+/CD8+ ratio in 4 of 4 patients, more CD5 loss in 2 of 4 patients, and more CD7 loss in 2 of 4 patients. TCR gene monoclonal rearrangement was detected in 2 of 5 patients. Narrowband ultraviolet B phototherapy was applied in 7 patients. One of 7 patients achieved complete response, and 6 of 7 patients achieved partial response. No recurrence was noted with the median follow-up period of 6 months. CONCLUSION: HMF could occur in young patients, with indolent and benign course. HMF could gradually seem as scaly erythema based on hypopigmented patches. The histopathology indicated a more advanced stage of the scaly erythema lesions than hypopigmented patches.

Mechanisms of repigmentation induced by photobiomodulation therapy in vitiligo.

Photobiomodulation (PBM) therapy is based on the exposure of biological tissues to low-level laser light (coherent light) or light-emitting diodes (LEDs; noncoherent light), leading to the modulation of cellular functions, such as proliferation and migration, which result in tissue regeneration. PBM therapy has important clinical applications in regenerative medicine. Vitiligo is an acquired depigmentary disorder resulting from disappearance of functional melanocytes in the involved skin. Vitiligo repigmentation depends on available melanocytes derived from (a) melanocyte stem cells located in the bulge area of hair follicles and (b) the epidermis at the lesional borders, which contains a pool of functional melanocytes. Since follicular melanoblasts (MBs) are derived from the melanocyte stem cells residing at the bulge area of hair follicle, the process of vitiligo repigmentation presents a research model for studying the regenerative effect of PBM therapy. Previous reports have shown favourable response for treatment of vitiligo with a low-energy helium-neon (He-Ne) laser. This review focuses on the molecular events that took place during the repigmentation process of vitiligo triggered by He-Ne laser (632.8 nm, red light). Monochromatic radiation in the visible and infrared A (IRA) range sustains matrix metalloproteinase (MMP), improves mitochondrial function, and increases adenosine triphosphate (ATP) synthesis and O2 consumption, which lead to cellular regenerative pathways. Cytochrome c oxidase in the mitochondria was reported to be the photoacceptor upon which He-Ne laser exerts its effects. Mitochondrial retrograde signalling is responsible for the cellular events by red light. This review shows that He-Ne laser initiated mitochondrial retrograde signalling via a Ca2+ -dependent cascade. The impact on cytochrome c oxidase within the mitochondria, an event that results in activation of CREB (cyclic-AMP response element binding protein)-related cascade, is responsible for the He-Ne laser promoting functional development at different stages of MBs and boosting functional melanocytes. He-Ne laser irradiation induced (a) melanocyte stem cell differentiation; (b) immature outer root sheath MB migration; (c) differentiated outer root sheath MB melanogenesis and migration; and (d) perilesional melanocyte migration and proliferation. These photobiomodulation effects result in perifollocular and marginal repigmentation in vitiligo.

Facial nevus depigmentosus getting remarkable repigmentation by treatment with a 308-nm excimer laser: A case report.

Nevus depigmentosus (ND) is a rare, congenital, nonprogressive depigmented lesion with irregular outline. To date, the few therapeutic approaches that have been developed to treat ND have yielded unsatisfactory results. We reported on a 6-month-old girl who presented with a ND on the right side of her face for 5 months. Treatment with a 308-nm excimer laser was started once a week at 300 mJ/cm2 and then was increased by 50-100 mJ/cm2 in each subsequent session until post-treatment erythema occurred. After 10 treatments, repigmentation in the lesion was evident and remained stable 1 month later at follow up. This case supports that the 308-nm excimer laser may be a good choice for the treatment of ND.

Excimer Light Treatment for Idiopathic Guttate Hypomelanosis: A Pilot Study.

BACKGROUND: Idiopathic guttate hypomelanosis (IGH) is a commonly acquired benign leukoderma characterized by multiple discrete, hypo- or depigmented macules often on extremities that can be aesthetically undesirable for patients. This is the first study using excimer laser for treatment. OBJECTIVE: To determine the effectiveness of excimer laser for repigmentation of idiopathic guttate hypomelanosis. METHODS AND MATERIALS: In this longitudinal, split-body controlled, single-blinded pilot study, 6 patients were treated with excimer laser for 12 weeks using the vitiligo protocol. Effectiveness was graded by the blinded observer scale through photographic comparisons at the end of the study. Participants also graded their progress at intervals during the study. A descriptive trend analysis and an ANOVA model were used to determine outcomes. RESULTS: Lesions that received the excimer treatment had significantly higher repigmentation by the end of the study compared with baseline and untreated lesions. CONCLUSION: Excimer laser treatments are already considered to be a safe modality for a variety of skin conditions. This study suggests that excimer is an effective treatment option with acceptable cosmetic outcomes for IGH.

The 308-nm excimer laser in the darkening of the white lines of striae alba.

OBJECTIVE: To evaluate the true efficacy of the 308-nm excimer laser for darkening striae alba using a modified approach. METHODS: Ten subjects were treated using the excimer laser on the white lines of striae, while the normal skin near to and between the lines was covered with zinc oxide cream. Assessment of efficacy was performed by colorimetric scores based on mexameter measurement and also digital photographs showing before-after laser therapy, which were compared by two independent dermatologists. RESULTS: The mexameter-based data analysis showed that the excimer laser was weakly effective in the repigmentation of the lines of striae. The analysis using before-after photographs showed that 80% of patients had a poor or moderate result. CONCLUSIONS: The results of this study showed the weakly positive effect of the 308-nm excimer laser in the repigmentation of striae alba; the splaying of pigment was a major side effect.

New and experimental treatments of vitiligo and other hypomelanoses.

This article deals with new and experimental treatments that can be used to treat various forms of depigmenting disorders. Ultraviolet B-focused therapies and new surgical approaches are analyzed in this article. These therapies were mainly or only developed to treat vitiligo, which is the most studied and probably the most challenging of all the hypomelanoses, but the results obtained in trials and clinical experiences about vitiligo sometimes can be referred to other depigmenting disorders.

Systemic toxicity from topically applied lidocaine in conjunction with fractional photothermolysis.

BACKGROUND: Topical anesthetics, unlike injectable anesthetics, can be applied painlessly and can provide sufficient pain control to maintain patient comfort throughout a variety of laser procedures. Although the use of topical lidocaine is considered relatively safe, instances of cardiotoxic and neurotoxic adverse events have been reported to occur. OBSERVATIONS: A 52-year-old woman underwent fractional photothermolysis for management of severe hypopigmentation and scarring of several years' duration. Shortly after termination of treatment to her face and neck, which required prolonged exposure to a 30% lidocaine gel compound both before and during surgery, she developed clinical signs and symptoms consistent with systemic lidocaine toxicity. The results of laboratory studies confirmed serum lidocaine levels within the toxic range. We postulate that the combination of the high concentration of topical lidocaine required to achieve sufficient anesthesia, together with the laser-induced disruption in epidermal barrier function, may have been responsible for this phenomenon. CONCLUSIONS: Application of a 30% topical lidocaine gel to a limited area in conjunction with fractional photothermolysis may generate serum lidocaine levels high enough to elicit systemic toxicity. Laser surgeons should be alert to this phenomenon, particularly in patients with underlying hepatic, endocrine, cardiac, or central nervous system/psychiatric dysfunction; in patients with a low body mass index; and in patients who are taking medications that may interfere with hepatic lidocaine metabolism.

The safety and efficacy of the 308-nm excimer laser for pigment correction of hypopigmented scars and striae alba.

OBJECTIVE: To assess the safety and efficacy of the 308-nm excimer laser in pigment correction of hypopigmented scars and striae alba. DESIGN: Institutional review board-approved randomized controlled trial. SETTING: Private research center. PATIENTS: Volunteer sample of 31 adult subjects with hypopigmented scars or striae alba distributed on the face, torso, or extremities. INTERVENTIONS: Lesions were randomized to receive treatment or not, with site-matched normal control areas. Treatments were initiated with a minimal erythema dose minus 50 mJ/cm(2) to affected areas. Subsequent treatments were performed biweekly until 50% to 75% pigment correction, then every 2 weeks thereafter until a maximum of 10 treatments, 75% increase in colorimetric measurements, or 100% visual pigment correction. MAIN OUTCOME MEASURES: Pigment correction by visual and colorimetric assessments compared with untreated control lesions and site-matched normal skin before each treatment and at 1-, 2-, 4-, and 6-month follow-up intervals. Occurrence of erythema, blistering, dyspigmentation, or other adverse effects was monitored. RESULTS: The percentage pigment correction by both assessments increased in direct proportion to the number of treatments. The mean percentage pigment correction by visual assessment relative to control of 61% (95% confidence interval [CI], 55%-67%) for scars and 68% (95% CI, 62%-74%) for striae was achieved after 9 treatments. The mean percentage pigmentation by colorimetric measurements relative to control of 101% (95% CI, 99%-103%) for scars and 102% (95% CI, 99%-104%) for striae was achieved after 9 treatments. Both sets of values gradually declined toward baseline levels during the 6-month follow-up. No blistering or dyspigmentation occurred. CONCLUSIONS: Therapy with the 308-nm excimer laser is safe and effective in pigment correction of hypopigmented scars and striae alba. Mean final pigment correction rates relative to control sites of approximately 60% to 70% by visual assessment and 100% by colorimetric analysis were observed after 9 treatments administered biweekly. Maintenance treatment every 1 to 4 months is required to sustain the cosmetic benefit.