Journal of Clinical and Aesthetic Dermatology

APR 2018

An evidence-based, peer-reviewed journal for practicing clinicians in the field of dermatology

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30 JCAD JOURNAL OF CLINICAL AND AESTHETIC DERMATOLOGY April 2018 • Volume 11 • Number 4 O R I G I N A L R E S E A R C H PBM-treated side, the findings of the pigment quantitative measurement (melanin index) were less impressive (Figure 3). However, the melanin index score on the PBM-treated side was significantly reduced in the majority of patients. DISCUSSION Melasma treatment remains a difficult task. Lasers in combination with topical treatments as well as chemical peels have been used in affected patients with variable results. 14 A mixture of topical retinoic acid, hydroquinone, and corticosteroid applied for several weeks has been extensively used to treat melasma, showing better results than hydroquinone monotherapy. 15 Unfortunately, skin irritation is very common, and long-term use might lead to exogenous ochronosis —dark blue hyperpigmentation localized where the causative agent (e.g., hydroquinone) was applied. For deeply located dermal melasma, topical medications cannot penetrate deep enough to reach the hyperactive melanocytes. Fortunately, light-based devices such as lasers can reach the dermis. However, pigment-specific high- energy lasers might worsen melasma or induce post-inflammatory hyperpigmentation with unpredictable efficacy. 16 There are many internal and external factors that determine the pigmentation dynamic process of human skin. 17 Based on the premise that melasma is a dynamic acquired pigmentary disorder, as opposed to an easily treated static, benign, pigmented lesion such as lentigines, a new treatment approach is needed. In this pilot study, we selected a treatment modality (PBM) that is capable of treating dynamic processes taking place in the dermis. Since 1968, there have been thousands of peer-reviewed articles describing PBM use. 10,18 Since it promotes faster wound healing and anti-inflammatory outcomes, PBM serves as an alternative therapy through its use of specific low energy, nonthermal light parameters acting within a range of wavelengths from visible to near-infrared (NIR). PBM does not traumatize the skin, while infrared wavelengths are poorly absorbed by melanin and photons can penetrate deeply into the dermis. Mobilization phase. Microdermabrasion. As a first step in our study, MCD was performed to open an epidermal window and mobilize a dynamic event (perivascular inflammatory infiltrate and vasodilation) prior to exposure to PBM photons (modulation phase). Light microscopy observations on pig skin by Lee et al 20 showed a reduction in the thickness and homogenization of the stratum corneum (SC) with focal compaction immediately after using a MCD device (negative pressure Al2O3 crystals) at 25cmHg (33.3KPa) for five seconds. Since we ablated the SC (corneocytes) using a stronger pressure (57Kpa=43cmHg), we probably triggered perivascular inflammatory infiltrate and vasodilation as formerly reported histopathologically following MCD. 21,22 In this study, we partially removed epidermal keratinocyte layers while avoiding damage to the basal membrane layer. Targeting signaling pathways in melanogenesis by photobiomodulation. Using cultured human melanocytes, Kim et al 24 showed that NIR FIGURE 1. A 4-point scale evaluation by 3 observers comparing before and after pictures (baseline vs. Week 12); results statistically significant (p<0.001) FIGURE 2. Melasma Area and Severity Index score showing a significant (p<0.001) improvement at Week 12 on the photobiomodulation-treated side

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