Depigmentation therapy in vitiligo universalis with cryotherapy and 4-hydroxyanisole

Chemical leukoderma: An insight of pathophysiology and contributing factors

Chemical leukoderma, or chemical-based vitiligo, is a dermal disease triggered by exposure to chemicals and characterized by the emergence of depigmentation or hypopigmentation of the skin. The etiology of this condition is associated with exposure to various chemical substances present in both occupational and non-occupational settings. The precise mechanism that underlies chemical leukoderma remains elusive and is believed to result from the demise of melanocytes, which are responsible for producing skin pigments. This condition has gained particular prominence in developing countries like India. An interesting connection between chemical leukoderma and vitiligo has been identified; studies suggest that exposure to many household chemicals, which are derivatives of phenols and catechol, may serve as a primary etiological factor for the condition. Similar to autoimmune diseases, its pathogenesis involves contributions from both genetic and environmental factors. Furthermore, over the last few decades, various studies have demonstrated that exposure to chemicals plays a crucial role in initiating and progressing chemical leukoderma, including cases stemming from occupational exposure.

Vitiligo Treatments: Review of Current Therapeutic Modalities and JAK Inhibitors

Vitiligo is a chronic autoimmune disease characterized by loss of pigment of the skin, affecting 0.5-2% of the population worldwide. It can have a significant impact on patients' quality of life. In recent years, there has been significant progress in our understanding of the pathogenesis of vitiligo. It is believed that vitiligo develops due to a complex combination of genetics, oxidative stress, inflammation, and environmental triggers. Conventional treatments include camouflage, topical corticosteroids, topical calcineurin inhibitors, oral corticosteroids, phototherapy, and surgical procedures, with the treatment regimen dependent on the patient's preferences and characteristics. With increased understanding of the importance of the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) pathway in the pathogenesis of vitiligo, treatment has expanded to include the first US FDA-approved cream to repigment patients with vitiligo. This review summarizes our understanding of the major mechanisms involved in the pathogenesis of vitiligo and its most common available treatments.

The use of lasers in vitiligo, an overview

Various types of lasers have been demonstrated to be effective in the treatment of vitiligo. The mode of action of these lasers is just as varied as the purpose of intervention. Many clinicians are not aware of the unique opportunity these lasers offer to improve the outcomes of vitiligo treatment. To date, no clear overview exists of the use of lasers in vitiligo treatment. Thus, the aim of this review is to discuss the various types of lasers and provide an overview of the evidence for their efficacy. We found good evidence from a systematic review that the excimer laser is effective, induces repigmentation rates comparable to NB‐UVB and has improved outcomes when combined with calcineurin inhibitors. Ablative lasers are commonly used for tissue graft or melanocyte–keratinocyte cell graft transplantation. They provide safe, fast and uniform denudation of the epidermis with propitious repigmentation outcomes. We found conflicting evidence from two systematic reviews regarding the efficacy of fractional ablative lasers for improving outcomes of NB‐UVB therapy, a systematic review including only fractional ablative lasers provided evidence for efficacy. Q‐switched nanosecond lasers have shown to be safe and effective for inducing depigmentation, although recurrence is common, and most studies were small and retrospective. Despite proven efficacy and safety, laser treatments are relatively expensive and suited for limited body surface areas and selected cases. Each type of laser has benefits and risks associated and should, therefore, be individually chosen based on location, extent, activity and type of vitiligo.

Chemical-Induced Vitiligo

Chemical-induced depigmentation of the skin has been recognized for more than 75 years, first as an occupational hazard but then extending to those using household commercial products as common as hair dyes. Since their discovery, these chemicals have been used therapeutically in patients with severe vitiligo to depigment their remaining skin and improve their appearance. Because chemical-induced depigmentation is clinically and histologically indistinguishable from nonchemically induced vitiligo, and because these chemicals appear to induce melanocyte autoimmunity, this phenomenon should be known as "chemical-induced vitiligo," rather than less accurate terms that have been previously used.

A holistic review on the autoimmune disease vitiligo with emphasis on the causal factors

Vitiligo is an idiopathic systemic autoimmune disease affecting skin, hair and oral mucosa. This genetic yet acquired disease characterized by melanin loss is a cause of morbidity across all races. Though thyroid disturbance has been recognized as a key trigger of this pathology, an array of other factors plays critical role in its manifestation. Multiple hormones (corticotropin-releasing hormone, adrenocorticotropic hormone, α-melanocyte-stimulating hormone, melatonin, calcitriol, testosterone, estrogen), genes (Human leukocyte antigen (HLA), Cytotoxic T lymphocyte-associated antigen 4 (CTLA-4), Forkhead box D3 (FOXD3), Cluster of differentiation 117 (CD117), Estrogen receptor (ESR) 1, Cyclooxygenase-2 (COX2), Vitiligo-associated protein 1 (VIT1)), and lifestyle choices (stress, diet, cosmetic products, and medications) have been suspected as drivers of this disorder. The pathological mechanisms have been understood in recent times, with the aid of genomic studies; however a universally-effective therapy is yet to be achieved. This review discusses these under-investigated facets of vitiligo onset and progression; hence, it is expected to enrich vitiligo research.

Depigmentation with Q-switched Nd:YAG laser in universal vitiligo: a long-term follow-up study of 4 years

Q-switched (QS) lasers are used for depigmentation in universal vitiligo, but there is limited data on long-term results after laser treatment. This study was conducted to assess the safety and long-term follow-up results of QS Nd:YAG laser treatment in combination with need-based topical depigmentation therapy for universal vitiligo. A retrospective study was performed on patients with universal vitiligo who had received QS Nd:YAG laser treatment from 2010 to 2013. All patients were contacted and called for follow-up. Patients who reported were assessed clinically and information regarding adverse effects and relapse (repigmentation) in the follow-up period were obtained. Any need for topical depigmenting creams or other interventions and overall satisfaction to treatment were also documented. Records of 34 patients were retrieved, out of whom 28 cases reported for the follow-up visit. Duration of follow-up ranged from 2 to 5 years (mean, 2.78). No long-term adverse effects were reported and the majority of patients were highly satisfied with treatment. Satisfactory results with >90% clearance of pigment was reported by 89.3% (25/28) of patients, out of whom 72% (18/25) had retained the therapeutic effect with the use of sunscreens with/without intermittent topical depigmentation therapies. In seven cases, partial to complete relapse was observed. QS Nd:YAG laser is an effective tool for treating residual pigmentation in universal vitiligo, and the therapeutic effect can be maintained in most cases with regular sunscreen use and need-based topical therapies.

A molecular systems approach to modelling human skin pigmentation: identifying underlying pathways and critical components

BACKGROUND

Ultraviolet radiations (UV) serve as an environmental stress for human skin, and result in melanogenesis, with the pigment melanin having protective effects against UV induced damage. This involves a dynamic and complex regulation of various biological processes that results in the expression of melanin in the outer most layers of the epidermis, where it can exert its protective effect. A comprehensive understanding of the underlying cross talk among different signalling molecules and cell types is only possible through a systems perspective. Increasing incidences of both melanoma and non-melanoma skin cancers necessitate the need to better comprehend UV mediated effects on skin pigmentation at a systems level, so as to ultimately evolve knowledge-based strategies for efficient protection and prevention of skin diseases.

METHODS

A network model for UV-mediated skin pigmentation in the epidermis was constructed and subjected to shortest path analysis. Virtual knock-outs were carried out to identify essential signalling components.

RESULTS

We describe a network model for UV-mediated skin pigmentation in the epidermis. The model consists of 265 components (nodes) and 429 directed interactions among them, capturing the manner in which one component influences the other and channels information. Through shortest path analysis, we identify novel signalling pathways relevant to pigmentation. Virtual knock-outs or perturbations of specific nodes in the network have led to the identification of alternate modes of signalling as well as enabled determining essential nodes in the process.

CONCLUSIONS

The model presented provides a comprehensive picture of UV mediated signalling manifesting in human skin pigmentation. A systems perspective helps provide a holistic purview of interconnections and complexity in the processes leading to pigmentation. The model described here is extensive yet amenable to expansion as new data is gathered. Through this study, we provide a list of important proteins essential for pigmentation which can be further explored to better understand normal pigmentation as well as its pathologies including vitiligo and melanoma, and enable therapeutic intervention.

Beyond vitiligo guidelines: combined stratified/personalized approaches for the vitiligo patient

'Vitiligo' is a word that bears endless possibilities and no promises. Each vitiligo patient has a different story that demands a different therapeutic approach. Even though great efforts have been made to evaluate, study, compare and document the different therapeutic modalities available for vitiligo, clearly handling their modes of actions as well as their side effects and establishing clear stratified guidelines, numerous dilemmas are frequently met on practical grounds. 'Stabilize', 'repigment', 'depigment' or 'camouflage'? 'for whom and how do we achieve the best results' ? 'Separately or in combination ? - questions that need to be answered and decisions need to be taken in the appropriate timing and altered when the necessity arises. In the current viewpoint, we have utilized the available knowledge and exploited years of experience in an attempt to go beyond the guidelines to set the rationale for an optimal and personalized therapy, within the framework of a stratified approach.

Depigmentation Therapy with Q-Switched Nd: YAG Laser in Universal Vitiligo

Background:

Any residual pigment left in patients of universal vitiligo is managed with topical treatments, cryotherapy, and lasers.

Aim:

The study aims to assess the efficacy and safety of Q-switched Nd: YAG laser in treating the residual pigmentation in patients with universal vitiligo.

Materials and Methods:

Fifteen patients of universal vitiligo with residual pigmentation on the face, hands, or feet, resistant to topical treatments, were treated with single or multiple sessions of Q-switched Nd: YAG laser treatment. Topical treatments were continued in between the laser sessions and the depigmentation achieved was monitored by clinical examination and repeat digital photographs. Response to the treatment was labelled as excellent if the residual pigment could be reduced by at least 90% while 50–90% resolution of pigmentation was labelled as a partial response. Adverse effects to the treatment offered were also monitored.

Results:

Thirteen of the 15 patients enrolled for the study showed an excellent response to the treatment offered. Two other patients showed a poor response with less than 50% resolution of pigmentation. The number of laser sessions needed at a particular site ranged from 1 to 3 and no patient was offered more than three sessions of laser treatment at any site. No significant adverse events were reported by any patient.

Conclusions:

Residual pigmentation in patients with universal vitiligo that does not respond to topical treatment options alone can be managed quite effectively with Q-switched Nd: YAG laser without any significant adverse effects.

Guidelines for the management of vitiligo: the European Dermatology Forum consensus

The aetiopathogenic mechanisms of vitiligo are still poorly understood, and this has held back progress in diagnosis and treatment. Up until now, treatment guidelines have existed at national levels, but no common European viewpoint has emerged. This guideline for the treatment of segmental and nonsegmental vitiligo has been developed by the members of the Vitiligo European Task Force and other colleagues. It summarizes evidence-based and expert-based recommendations (S1 level).

Vitiligo: an update on current pharmacotherapy and future directions

INTRODUCTION

Vitiligo is a common pigmentary skin disorder, characterized by the appearance of white macules on the skin, mucosal or hair. Treatment is often a tough challenge and involves a wide range of therapies.

AREAS COVERED

This review focuses on available first- and second-line pharmacological treatments for vitiligo. In particular, the mechanisms of action, the main indications, the efficacy and the most important side effects are reviewed. Moreover, a brief discussion is provided, regarding other nonpharmacological treatments, such as phototherapy and surgical options, due to their importance and successful outcomes in vitiligo treatment. Finally, a concise overview regarding the future directions in vitiligo therapy is presented.

EXPERT OPINION

The promising outcomes reported here demonstrate that it is possible to achieve a satisfactory and often stable repigmentation of vitiligo lesions. Topical corticosteroids, calcineurin inhibitors, phototherapy and photochemotherapy represent the first-line therapeutic options, due to their safety and efficacy, whereas vitamin D analogues, targeted phototherapy, oral corticosteroids and surgery should be used as second-line therapies. Other therapies, such as antioxidants, can be used in association with other therapeutic options, whereas depigmenting agents should be used only in cases of extensive vitiligo, recalcitrant to other treatments.