Histologic and ultrastructural analysis of melasma after fractional resurfacing

Definition of refractory melasma and its treatment: a review

Although patients with refractory melasma have been treated using various methods, there is still no precise definition or summary of the therapies. To define refractory melasma and conduct a review of the treatments, we searched for relevant publications in PubMed, Web of Science, and the Cochrane Library, and a total of 35 references were obtained. Refractory melasma can be roughly defined as an ineffective treatment for melasma, including topical bleaching agents, chemical peels, laser therapy, microdermabrasion for more than six months, or chemical peels treated more than six times. Meanwhile, physicians should be careful when treating patients with darker skin and dermal or mixed types of melasma since these individuals do not respond well to treatment. Lasers combined with other methods, especially different types of lasers or topical agents, are considered more effective than monotherapy. Oral tranexamic acid (TXA) is a prospective cure for refractory melasma. Other methods include a combination of chemical peels, microneedling, or injections with additional therapies. In conclusion, we were able to provide a rough definition of refractory melasma and list the available therapies. According to the literature, the most prevalent treatment is laser combination therapy. However, laser treatment should be considered only after topical agents and chemical peeling have failed. Considering its side effects, efficacy, and safety, oral TXA may be a better option, but more research is needed to make a firm conclusion. Moreover, maintenance therapy is required after treatment.

Management of Melasma: Laser and Other Therapies-Review Study

Melasma is a commonly occurring pigmented skin condition that can significantly affect one's appearance, described as symmetric hyperpigmentation that presents as irregular brown to gray-brown macules on various facial areas, such as the cheeks, forehead, nasal bridge, and upper lip, along with the mandible and upper arms. Due to its complex pathogenesis and recurrent nature, melasma management is challenging and the outcomes following treatment are not always deemed satisfactory. Solely treating hyperpigmentation may prove ineffective unless paired with regenerative techniques and photoprotection, since one of the main reasons for recurrence is sun exposure. Hence, the treatment protocol starts with addressing risk factors, implementing stringent UV protection, and then treatment using different strategies, like applying topical treatments, employing chemical peels, laser and light therapies, microneedling, and systemic therapy. This review aims to provide a summary of the effectiveness and safety of the frequently employed laser and light therapies for treating melasma, focusing on laser therapy as a treatment for melasma.

Is Tranexamic Acid Use Effective in Preventing Postinflammatory Hyperpigmentation after Laser Treatment? A Systematic Review and Meta-Analysis

Postinflammatory hyperpigmentation (PIH) is one of the most prevalent complications of laser treatment. However, comprehensive evidence is lacking to confirm the effect of tranexamic acid (TXA) for the prevention of postlaser PIH. We classified laser combined with TXA as the experimental group and laser alone as the control group from the selected studies in order to determine the efficacy of the extra use of TXA. We conducted a comprehensive literature review of randomized controlled trials (RCTs) that matched TXA coupled with laser vs. laser alone. The melanin index (MI) scores were employed as the clinically improved outcomes. Seven RCTs and a total of 222 individuals were evaluated in this meta-analysis. The findings revealed no statistically significant difference between the TXA and control groups in terms of decrease in mean MI scores at the end of the research ( $P=0.45$ ). The subgroup analysis showed that at month 1, extra use of TXA after laser treatment resulting in a statistically significant decrease in MI as opposed to laser alone ( $P=0.04$ ). However, at months 2 ( $P=0.73$ ), 3 ( $P=0.85$ ), and 6 ( $P=0.64$ ), the decrease in MI scores was not statistically significant. In addition, there was no statistically significant difference between topical, oral, and intradermal TXA on the reduction of MI scores after treatment ( $P=0.61$ ). Furthermore, nausea and menorrhagia occurred in the oral TXA group. The current meta-analysis found limited temporary efficacy of TXA in preventing postlaser PIH after 1 month.

Fractional carbon dioxide laser versus trichloroacetic acid peel in the treatment of pseudo-acanthosis nigricans

BACKGROUND

Treatment of acanthosis nigricans (AN) is challenging, and new modalities are being explored continuously to increase the therapeutic efficacy.

AIM

To evaluate the efficacy and safety of fractional CO2 laser compared to trichloroacetic acid (TCA) peel in the treatment of pseudo-acanthosis nigricans (pseudo-AN).

METHODS

The study included 40 patients with pseudo-AN on the neck and axilla allocated into two groups each containing 20 patients. Group (A) was treated with TCA 20% peel applied on the pigmented area while group (B) received fractional CO2 laser. Both treatments were performed till complete clearance or for a maximum of four treatment sessions. Patients with excellent response were further followed up for 6 months after the end of treatment.

RESULTS

Both modalities were effective in the treatment of pseudo-AN; however, the therapeutic response was significantly higher in the fractional CO2 laser group compared to the TCA peel group (p < 0.01). Marked to excellent response (51%-100% clearance of AN lesions) was achieved in 85% of the patients in the fractional laser group versus 10% of the patients in the TCA group. Adverse effects, for example, persistent erythema, post-inflammatory hyperpigmentation, and burning sensation, were also statistically higher in the TCA group compared to the laser group (p = 0.04).

CONCLUSION

Fractional CO2 laser is a promising effective and well-tolerated treatment modality for pseudo-acanthosis nigricans.

Micro-needling versus fractional carbon dioxide laser for delivery of tranexamic acid in the treatment of melasma: A split-face study

BACKGROUND

Tranexamic acid (TXA) in oral, topical, and intra-dermal injection routes showed efficacy in melasma treatment. Micro-needling and fractional carbon dioxide (CO₂ ) laser were reported to enhance the drug delivery of TXA.

AIMS

This study aimed at comparing the use of micro-needling and fractional CO₂ laser for drug delivery of TXA in the treatment of facial melasma.

PATIENTS/METHODS

Thirty female patients with bilateral symmetrical facial melasma were subjected to micro-needling, for one side of the face, and fractional CO₂ laser, for the other, followed by an immediate topical application of TXA solution 4 mg/mL. Patients received six biweekly sessions.

RESULTS

Two weeks after the last session, a significant reduction in baseline modified melasma area and severity index (mMASI) score was observed on both sides. The mean ± SD baseline mMASI dropped from 3.43 ± 1.84 to 1.59 ± 1.51 (mean reduction 57.73%, P < .001) and from 3.51 ± 1.84 to 1.78 ± 1.51 (mean reduction 55.82%, P < .001) in the micro-needling-treated side and in the fractional CO₂ laser-treated side, respectively. However, no statistically significant differences were found between the two sides (P = .81).

CONCLUSIONS

Micro-needling and fractional CO₂ laser are equally safe and effective for the delivery of TXA in the treatment of facial melasma.

Laser treatment of medical skin disease in women

Laser treatment is a relatively new and increasingly popular modality for the treatment of many dermatologic conditions. A number of conditions that predominantly occur in women and that have a paucity of effective treatments include rosacea, connective tissue disease, melasma, nevus of Ota, lichen sclerosus (LS), notalgia paresthetica and macular amyloidosis, and syringomas. Laser therapy is an important option for the treatment of patients with these conditions. This article will review the body of literature that exists for the laser treatment of women with these medical conditions.

Photoaging and the clinical utility of fractional laser

The description of atomic structure by Niels Bohr set the basis for the emergence of quantum physics. Based on these fundamentals, Einstein published in 1917 a paper on the amplification of energy by Stimulated Emission of Radiation as part of his quantum theories. In 1955, Townes and Gordon turned Einstein’s theories into practice, creating a coherent and amplified microwave device using ammonia gas in an optical medium. But it was at the beginning of the 1980s, that Anderson and Parrish published an article about the selective photothermolysis model which revolutionized clinical practice. The use of laser in photoaging began with CO₂ (10,600 nm). In 1989, it was first used for resurfacing of a face with prominent photoaging. Ablative lasers have therefore had great popularity in the 1980s and 1990s, but prolonged postoperative time and significant risk of side effects have lowered the acceptance by patients. In 2004, the description of the fractionated radiation for the treatment of photoaging, by Mainstein, represented a great event. The stimulation of collagen occurred through fractional laser beams, which would reach the selected area while saving islands of sound skin. These islands accelerated the process of cicatrization of the treated tissue and shortened the postprocedure time. Furthermore, the fractionated radiation presented a smaller range of side effects, increasing the safety of the procedure. As mentioned earlier, as fractional lasers incise on the skin, they leave islands of healthy skin that accelerate recovery, while generating necrosis columns. Such necrosis columns remove damaged extracellular matrix material, allowing resettlement of fibroblasts. Such resettled fibroblasts, under the influence of a new tensile strength, restart to produce structures for extracellular matrix, such as collagen, elastin, and proteoglycans, in a more physiological way. Fractional lasers are considered by many dermatologists as the best choice in laser therapy for the treatment of photoaging.

High intensity focused ultrasound as a potential new modality for the treatment of pigmentary skin disorder

BACKGROUND/PURPOSE

The clinical skin tightening benefits of high intensity focused ultrasound (HIFU) have been established, but its mechanism of action in pigmented skin disorders remains unknown. We macroscopically and histopathologically investigated dermatological changes after HIFU at different exposure doses in a UVB-induced guinea pig model of hyperpigmentation.

METHODS

We applied HIFU irradiation at 0.1 and 0.2 J/cm(2) to UVB-induced spotty hyperpigmentation in guinea pig skin. The therapeutic effects of HIFU were judged based on gross appearance using photography, dermoscopy, and chromametry during a period of 3 weeks after HIFU irradiation. Histological assessments were performed using Fontana-Masson staining 1 day before and 3 weeks after HIFU irradiation.

RESULTS

Macroscopically, UVB-induced hyperpigmentation was significantly reduced 2 weeks after HIFU with 0.2 J/cm(2) , and 3 weeks after HIFU with 0.1 J/cm(2) . Histopathologically, the heavy deposition of melanin in the epidermis induced by UVB exposure was reduced 3 weeks after HIFU irradiation.

CONCLUSION

We confirmed that HIFU has a positive effect on UVB-induced hyperpigmentation as well as mechanical destructive activity. We suggest that HIFU may be useful as an alternative modality for human patients suffering from skin pigmentary conditions.

Evidence-based treatment for melasma: expert opinion and a review

Introduction

Melasma is one of the most common pigmentary disorders seen by dermatologists and often occurs among women with darker complexion (Fitzpatrick skin type IV–VI). Even though melasma is a widely recognized cause of significant cosmetic disfigurement worldwide and in India, there is a lack of systematic and clinically usable treatment algorithms and guidelines for melasma management. The present article outlines the epidemiology of melasma, reviews the various treatment options along with their mode of action, underscores the diagnostic dilemmas and quantification of illness, and weighs the evidence of currently available therapies.

Methods

A panel of eminent dermatologists was created and their expert opinion was sought to address lacunae in information to arrive at a working algorithm for optimizing outcome in Indian patients. A thorough literature search from recognized medical databases preceded the panel discussions. The discussions and consensus from the panel discussions were drafted and refined as evidence-based treatment for melasma. The deployment of this algorithm is expected to act as a basis for guiding and refining therapy in the future.

Results

It is recommended that photoprotection and modified Kligman’s formula can be used as a first-line therapy for up to 12 weeks. In most patients, maintenance therapy will be necessary with non-hydroquinone (HQ) products or fixed triple combination intermittently, twice a week or less often. Concomitant camouflage should be offered to the patient at any stage during therapy. Monthly follow-ups are recommended to assess the compliance, tolerance, and efficacy of therapy.

Conclusion

The key therapy recommended is fluorinated steroid containing 2–4% HQ-based triple combination for first line, with additional selective peels if required in second line. Lasers are a last resort.

Electronic supplementary material

The online version of this article (doi:10.1007/s13555-014-0064-z) contains supplementary material, which is available to authorized users.

Low-power fractional CO₂ laser versus low-fluence Q-switch 1,064 nm Nd:YAG laser for treatment of melasma: a randomized, controlled, split-face study

BACKGROUND

Various laser treatments are currently available for melasma but their use remains challenging because of potential side effects.

OBJECTIVE

The aim of this randomized controlled study was to compare the efficacy and safety of low-fluence Q-switch 1,064 nm Nd:YAG and low-power fractional CO2 laser using a split-face design.

MATERIALS AND METHODS

A total of 40 female patients with symmetric melasma were enrolled to the study and each side of their face was randomly allocated to either low-fluence Q-switch 1,064 nm Nd:YAG or low-power fractional CO2 laser. They were treated every 3 weeks for five consecutive sessions and followed for 2 months after the last treatment session. Response to treatment was assessed using the Melanin Index (MI) score, modified Melasma Area and Severity Index (mMASI) score, and a subjective self-assessment method.

RESULTS

At the 2-month follow-up visit, both sides of the face had statistically significant reductions in the MI and mMASI scores compared with the first visit (p < 0.001). The differences between the mean MI and mMASI scores at baseline and at 2-month follow-up were compared between the two treatments and results showed that the reduction of MI and mMASI score in the fractional CO2 laser-treated side was significantly more than on the Q-switch 1,064 nm Nd:YAG laser-treated side (p < 0.001). There were no significant adverse effects with either of the laser treatments.

CONCLUSION

The present study shows that low-power fractional CO2 laser is safe and effective and can be considered as a valuable approach in the treatment of melasma.

Lasers as an approach for promoting drug delivery via skin

INTRODUCTION

Using lasers can be an effective drug permeation-enhancement approach for facilitating drug delivery into or across the skin. The controlled disruption and ablation of the stratum corneum (SC), the predominant barrier for drug delivery, is achieved by the use of lasers. The possible mechanisms of laser-assisted drug permeation are the direct ablation of the skin barrier, optical breakdown by a photomechanical wave and a photothermal effect. It has been demonstrated that ablative approaches for enhancing drug transport provide some advantages, including increased bioavailability, fast treatment time, quick recovery of SC integrity and the fact that skin surface contact is not needed. In recent years, the concept of using laser techniques to treat the skin has attracted increasing attention.

AREAS COVERED

This review describes recent developments in using nonablative and ablative lasers for drug absorption enhancement. This review systematically introduces the concepts and enhancement mechanisms of lasers, highlighting the potential of this technique for greatly increasing drug absorption via the skin. Lasers with different wavelengths and types are employed to increase drug permeation. These include the ruby laser, the erbium:yttrium-gallium-garnet laser, the neodymium-doped yttrium-aluminum-garnet laser and the CO2 laser. Fractional modality is a novel concept for promoting topical/transdermal drug delivery. The laser is useful in enhancing the permeation of a wide variety of permeants, such as small-molecule drugs, macromolecules and nanoparticles.

EXPERT OPINION

This potential use of the laser affords a new treatment for topical/transdermal application with significant efficacy. Further studies using a large group of humans or patients are needed to confirm and clarify the findings in animal studies. Although the laser fluence or output energy used for enhancing drug absorption is much lower than for treatment of skin disorders and rejuvenation, the safety of using lasers is still an issue. Caution should be used in optimizing the feasible conditions of the lasers in balancing the effectiveness of permeation enhancement and skin damage.

Treatment of refractory melasma with combination of topical 5% magnesium ascorbyl phosphate and fluorescent pulsed light in Asian patients

BACKGROUND

Melasma is an acquired disorder of hypermelanosis of great psychosocial concern. The treatments with various conventional therapies are often unsatisfactory. Lasers and light sources have been used to treat pigmented lesions, but in Asian skin with higher melanin content, such treatments may be challenging.

OBJECTIVES

To determine the effectiveness of treating melasma with a combination of topical 5% magnesium ascorbyl phosphate (MAP) and fluorescent pulsed light (FPL).

MATERIALS AND METHODS

Patients of skin types III-V with refractory melasma were treated for 12 weeks with topical application of 5% MAP and three sessions of FPL (570-950 nm) at 3, 6, and 9 weeks (fluence 12-14 J/cm(2) , pulse width 15 ms, and spot size 3 cm(2) ). They were followed up for another 12 weeks to assess the persistence of treatment benefit. Digital photographs of the patients were taken at each visit. Treatment efficacy was determined by calculating mean melasma area and severity index (MASI) at the beginning and then at weeks 6, 12, and 24. The subjective assessment was done by comparing pre-treatment and post-treatment photographs by an independent observer and self-assessment by patients using four-point scoring scale (1, poor, 2, fair, 3, good, and 4, excellent).

RESULTS

Sixty-five patients completed the study. The baseline mean MASI score of 14.80 decreased to 4.53 at the 12th week (end of treatment) and 6.35 at the 24th week (end of follow-up). The overall regression of mean MASI at these end-points was 69.3% and 57% (P < 0.01). The pre- and post-treatment photographic evaluation by independent observer and patients' self-assessment at the 12th week showed good to excellent response (scores 3 and 4) in 52.3% and 44.6% cases, respectively. No significant adverse effects of treatment were noted.

CONCLUSION

Combination of 5% MAP with FPL is effective, well tolerated, and safe in treating refractory melasma in Asian patients but for persistent improvement, maintenance treatments would be required.

The dual toning technique for melasma treatment with the 1064 nm Nd: YAG laser: A preliminary study

BACKGROUND AND AIMS

Melasma is a treatment-resistant and acquired pigmentary facial skin condition of uncertain etiology particularly prevalent in the older Asian female. Traditional bleaching agents have offered some success. Intense pulsed light (IPL), fractionated nonablative and more recently ablative laser technology have also been used, but were associated with postoperative hyperpigmentation in the Asian skin. The present study examined the consecutive application of 2 modes of the 1064 nm Nd:YAG laser in the 'dual toning' process.

SUBJECTS AND METHODS

Thirty females, mean age 41.4 ± 11.96 yr, Fitzpatrick skin type IV, participated in the prospective uncontrolled study. All subjects were treated with the 1064 nm Nd:YAG laser, first with the 5 ns Q-switched mode, 1.2 J/cm(2), 8 mm collimated handpiece with multiple passes and then immediately after with the micropulsed mode, 300 µs, 7.0 J/cm(2), 5 mm handpiece, multiple passes. Mild and even erythema was the endpoint. Treatments were given every other week until maximum improvement was obtained. Improvement was rated at a final assessment 6 weeks after the final treatment on a 5 point scale where 1 was little or no improvement and 5 was maximum improvement.

RESULTS

At the final treatment session and at the 6-week assessment, 20 of the 30 patients (67%) saw a fair to excellent degree of improvement, 7 (23%) had visible improvement and little or no improvement was seen in 3 (10%) patients. There were no unexpected side effects in any patients.

CONCLUSIONS

The dual toning technique using the 1064 nm Nd:YAG laser was safe and effective, and well-tolerated by all patents without anesthesia. Larger controlled studies are merited with more objective measurement techniques to confirm the results of this preliminary study.

Current status of surgery in dermatology

An article titled "Current issues in dermatologic office-based surgery" was published in the JAAD in October 1999 (volume 41, issue 4, pp. 624-634). The article was developed by the Joint American Academy of Dermatology/American Society for Dermatologic Surgery Liaison Committee. A number of subjects were addressed in the article including surgical training program requirements for dermatology residents and selected advances in dermatologic surgery that had been pioneered by dermatologists. The article concluded with sections on credentialing, privileging, and accreditation of office-based surgical facilities. Much has changed since 1999, including more stringent requirements for surgical training during dermatology residency, and the establishment of 57 accredited Procedural Dermatology Fellowship Training Programs. All of these changes have been overseen and approved by the Residency Review Committee for Dermatology and the Accreditation Committee for Graduate Medical Education. The fertile academic environment of academic training programs with interaction between established dermatologic surgeons and fellows, as well as the inquisitive nature of many of our colleagues, has led to the numerous major advances in dermatologic surgery, which are described herein.

The use of ablative lasers in the treatment of facial melasma

Melasma represents a pigmentary disorder that is difficult to treat. This study aims to broadly review the use of ablative lasers (Er:YAG and CO2) in the treatment of melasma, presenting the level of evidence of studies published to date. A total of 75 patients were enrolled in four case series studies (n=39), one controlled clinical trial (n=6) and one randomized controlled clinical trial (n=30). Studies on the Er:YAG laser showed better results with the use of short square-shaped pulses, which determined low rates of post-inflammatory hyperpigmentation and long-lasting maintenance of results. Likewise, studies on the CO2 laser proved the benefits of short pulse duration along with low-density energy. Post-treatment maintenance with the use of antipigmenting creams was necessary and effective to sustain long-term results. Ablative lasers may represent another useful and effective tool against melasma. Postinflammatory hyperpigmentation and difficulty in sustaining long-term results still represent the main limitations to a broader use of ablative lasers. Based on actual evidence, the use of this technology should be restricted to patients with recalcitrant disease. Further studies will help establish optimal laser parameters and treatment regimens.

Salicylic acid for the treatment of melasma: new acquisitions for monitoring the clinical improvement

OBJECTIVE

The Melasma Area and Severity Index (MASI) and the Melasma Severity Score (MSS) are calculated on the basis of only a subjective clinical assessment. This raises the need to have an objective score, uniform in the evaluation by different clinicians. The purpose of this study was to establish if the images by Canfield Reveal Imager can be correlated to MASI score to better evaluate the clinical efficacy of salicylic acid 33% peeling in the treatment of melasma respect to the clinical observation.

METHODS

The study was a voluntary observational study. Twenty female patients affected with melasma, aged between 30 and 60 years, were included in the study. Treatment with salicylic acid 33% was performed once a month, for a total of four times. The dermatologist (Doc A) examined each patient's melasma areas using MASI score, at the face-to-face observation and at Reveal images evaluation during the first (T0) and the end point time (T4). Digital photographs were also evaluated by another experienced dermatologist (Doc B), who has never seen clinically the patients before and who evaluated MASI score by Reveal images at time T0 and T4.

RESULTS

Student's t-test and linear regression test were performed, showing statistically significant values comparing MASI score obtained by digital photo and MASI score obtained clinically.

CONCLUSION

The monitoring of the improvement by Reveal images can optimize the treatment approach and the efficacy of same dermocosmetics procedures can be revised following standard criteria.

Risk assessment of excess drug and sunscreen absorption via skin with ablative fractional laser resurfacing : optimization of the applied dose for postoperative care

The ablative fractional laser is a new modality used for surgical resurfacing. It is expected that laser treatment can generally deliver drugs into and across the skin, which is toxicologically relevant. The aim of this study was to establish skin absorption characteristics of antibiotics, sunscreens, and macromolecules via laser-treated skin and during postoperative periods. Nude mice were employed as the animal model. The skin received a single irradiation of a fractional CO2 laser, using fluences of 4-10 mJ with spot densities of 100-400 spots/cm(2). In vitro skin permeation using Franz cells was performed. Levels of skin water loss and erythema were evaluated, and histological examinations with staining by hematoxylin and eosin, cyclooxygenase-2, and claudin-1 were carried out. Significant signs of erythema, edema, and scaling of the skin treated with the fractional laser were evident. Inflammatory infiltration and a reduction in tight junctions were also observed. Laser treatment at 6 mJ increased tetracycline and tretinoin fluxes by 70- and 9-fold, respectively. A higher fluence resulted in a greater tetracycline flux, but lower skin deposition. On the other hand, tretinoin skin deposition increased following an increase in the laser fluence. The fractional laser exhibited a negligible effect on modulating oxybenzone absorption. Dextrans with molecular weights of 4 and 10 kDa showed increased fluxes from 0.05 to 11.05 and 38.54 μg/cm(2)/h, respectively. The optimized drug dose for skin treated with the fractional laser was 1/70-1/60 of the regular dose. The skin histology and drug absorption had recovered to a normal status within 2-3 days. Our findings provide the first report on risk assessment of excessive skin absorption after fractional laser resurfacing.

Melasma in men

Melasma is an acquired hypermelanosis that results in localized hyperpigmentation, commonly found on the face. This condition is much more common in women than men. There are some features of melasma in men that seem to differ from those seen in women. However, there is a paucity of data on this topic. The aim of this article is to review the etiology, clinical presentation, and treatment of melasma in men. It is important for dermatologists to understand some unique aspects of melasma in this group to provide appropriate care for patients who suffer from this frustrating condition.

Skin permeation of small-molecule drugs, macromolecules, and nanoparticles mediated by a fractional carbon dioxide laser: the role of hair follicles

PURPOSE

To evaluate skin permeation enhancement mediated by fractional laser for different permeants, including hydroquinone, imiquimod, fluorescein isothiocyanate-labeled dextran (FD), and quantum dots.

METHODS

Skin received a single irradiation of a fractional CO(2) laser, using fluence of 2 or 4 mJ with densities of 100 ∼ 400 spots/cm(2). In vitro and in vivo skin penetration experiments were performed. Fluorescence and confocal microscopies for imaging delivery pathways were used.

RESULTS

The laser enhanced flux of small-molecule drugs 2 ∼ 5-fold compared to intact skin. A laser fluence of 4 mJ with a 400-spot/cm(2) density promoted FD flux at 20 and 40 kDa from 0 (passive transport) to 0.72 and 0.43 nmol/cm(2)/h, respectively. Microscopic images demonstrated a significant increase in fluorescence accumulation and penetration depth of macromolecules and nanoparticles after laser exposure. Predominant routes for laser-assisted delivery may be intercellular and follicular transport. CO(2) laser irradiation produced 13-fold enhancement in follicular deposition of imiquimod. Laser-mediated follicular transport could deliver permeants to deeper strata. Skin barrier function as determined by transepidermal water loss completely recovered by 12 h after irradiation, much faster than conventional laser treatment (4 days).

CONCLUSIONS

Fractional laser could selectively enhance permeant targeting to follicles such as imiquimod and FD but not hydroquinone, indicating the importance of selecting feasible drugs for laser-assisted follicle delivery.

Lasers for treatment of melasma and post-inflammatory hyperpigmentation

Hyperpigmentary disorders, especially melasma and post-inflammatory hyperpigmentation (PIH), cause significant social and emotional stress to the patients. Although many treatment modalities have been developed for melasma and PIH, its management still remains a challenge due to its recurrent and refractory nature. With the advent of laser technology, the treatment options have increased especially for dermal or mixed melasma. To review the literature on the use of cutaneous lasers for melasma and PIH. We carried out a PubMed search using following terms “lasers, IPL, melasma, PIH”. We cited the use of various lasers to treat melasma and PIH, including Q-switched Nd:YAG, Q-switched alexandrite, pulsed dye laser, and various fractional lasers. We describe the efficacy and safety of these lasers for the treatment of hyperpigmentation. Choosing the appropriate laser and the correct settings is vital in the treatment of melasma. The use of latter should be restricted to cases unresponsive to topical therapy or chemical peels. Appropriate maintenance therapy should be selected to avoid relapse of melasma.

Treatment of melasma using a novel 1,927-nm fractional thulium fiber laser: a pilot study

BACKGROUND

A 1,927-nm wavelength was recently added to the 1,550-nm erbium-doped fiber laser. This wavelength possesses a higher absorption coefficient for water than the 1,550-nm, conferring greater ability to target epidermal processes such as dyschromia.

OBJECTIVE

To evaluate the efficacy and safety of a novel 1,927-nm fractional thulium fiber laser in the treatment of melasma.

METHODS

Fourteen patients underwent three to four laser treatments (at 4-week intervals) at pulse energies of 10 to 20 mJ and total densities of 252 to 784 microscopic treatment zones per cm(2) (6-8 passes) using a 1,927-nm thulium fiber laser. Three blinded assessors and the patients evaluated clinical improvement of treatment areas at 1-, 3-, and 6-month follow-ups. Side effects were assessed, and pain was scored using a visual analog scale (0-10).

RESULTS

A statistically significant 51% reduction in MASI score was observed at 1-month post 3 to 4 laser treatments. A 33% (p = .06) and 34% (p = .07) reduction in Melasma Area and Severity Index score was observed at the 3- and 6-month follow-up visits, respectively. Skin responses observed after treatment were moderate erythema and mild edema. No scarring or postinflammatory hyper- or hypopigmentation was observed.

CONCLUSION

The 1,927-nm fractional thulium fiber laser is a safe, effective treatment for melasma.