Preliminary evaluation of vitiligo using in vivo reflectance confocal microscopy

Vitiligo Treated with Combined Piperine-Based Topical Treatment and Narrowband Ultraviolet B Therapy: Follow-Up with Reflectance Confocal Microscopy

BACKGROUND

Reflectance confocal microscopy (RCM) has a defined in vivo morphology of vitiligo and re-pigmentation. Combination therapies seem more effective than monotherapies.

OBJECTIVE

We aim to describe the clinical and RCM features of re-pigmentation with combined narrowband ultraviolet B (NB-UVB) and piperine-based topical treatment in localized vitiligo.

METHODS

Eight patients enrolled at a single center received combined treatment: topical treatment was applied twice daily + NB-UVB twice weekly for 2 × 2-month periods. Clinical changes were analyzed by the Vitiligo Noticeability Scale (VNS) and percentage of re-pigmentation. The evaluator agreement was assessed. Predefined RCM features had the presence/absence of (i) blood vessels, (ii) dendritic cells, and the quantity of (i) an irregular honeycombed pattern and (ii) non-pigmented papillae. Clinical and RCM monitoring was performed at the baseline, 2, 3, 5, and 7 months.

RESULTS

Macules were "slightly less noticeable" with 25-50% re-pigmentation. Irregular honeycomb patterns and non-pigmented papillae were significantly less frequently observed, and in less extended areas (T1 vs. T2, p = 0.039; T0 vs. T1, p = 0.005 and T2 vs. T4, p = 0.033). Dendritic cells and blood vessels improved, with significant changes in blood vessels (T1 vs. T2, p = 0.005 and T3 vs. T4, p = 0.008).

CONCLUSIONS

RCM confirms the morphological changes induced by combined treatment for localized vitiligo.

Feasibility of High-Cellular-Resolution Full-Field, Artificial-Intelligence-Assisted, Real-Time Optical Coherence Tomography in the Evaluation of Vitiligo: A Prospective Longitudinal Follow-Up Study

Vitiligo, a psychologically distressing pigmentary disorder characterized by white depigmented patches due to melanocyte loss, necessitates non-invasive tools for early detection and treatment response monitoring. High-cellular-resolution full-field optical coherence tomography (CRFF-OCT) is emerging in pigmentary disorder assessment, but its applicability in vitiligo repigmentation after tissue grafting remains unexplored. To investigate the feasibility of CRFF-OCT for evaluating vitiligo lesions following tissue grafting, our investigation involved ten vitiligo patients who underwent suction blister epidermal grafting and laser ablation at a tertiary center between 2021 and 2022. Over a six-month period, clinical features, dermoscopy, and photography data were recorded. Utilizing CRFF-OCT along with artificial intelligence (AI) applications, repigmentation features were captured and analyzed. The CRFF-OCT analysis revealed a distinct dark band in vitiligo lesion skin, indicating melanin loss. Grafted areas exhibited melanocytes with dendrites around the epidermal-dermal junction and hair follicles. CRFF-OCT demonstrated its efficacy in the early detection of melanocyte recovery and accurate melanin quantification. This study introduces CRFF-OCT as a real-time, non-invasive, and in vivo evaluation tool for assessing vitiligo repigmentation, offering valuable insights into pigmentary disorders and treatment responses.

The role of reflectance confocal microscopy in the diagnosis and management of pigmentary disorders: A review

BACKGROUND

Reflectance confocal microscopy (RCM) has quickly transitioned from a research tool to an adjunct diagnostic bedside tool, providing the opportunity for noninvasive evaluation of skin lesions with histologic resolution. RCM is an optical imaging technique that uses near-infrared excitation wavelengths and safe low-power lasers. En-face images of different skin layers (up to the superficial dermis) are acquired in grayscale based on the reflective indices of tissue components. Melanin has the highest reflective index (contrast) and appears bright on RCM.

AIMS

We present a review of the current literature on the use of RCM in the diagnosis and management of pigmentary disorders.

METHODS

We reviewed PubMed and Ovid Medline databases from January 2000 to June 2021, using MeSH key terms: "reflectance confocal microscopy, confocal laser scanning microscopy, pigmentary disorders, treatment, melasma, vitiligo, freckles, solar lentigo, lentigo, tattoo, complications, melanoma, skin cancers, pigmented lesions, post inflammatory, melanin, photoaging" to identify studies and review articles discussing the use of RCM in the diagnosis and management of pigmentary disorders.

RESULTS

RCM findings of pigmentary disorders were divided into the following categories: (1) disorders of increased pigmentation (post-inflammatory hyperpigmentation, melasma, Riehl's melanosis, solar lentigines, ephelides, hori nevus, naevus of Ota, café-au-lait macules, melanocytic nevus, melanoma, nevus spilus, labial mucosal melanosis, and mucosal melanoma), (2) disorders of decreased pigmentation or depigmentation (post-inflammatory hypopigmentation, vitiligo, nevus depigmentosus, halo nevus), and (3) exogenous pigmentation (tattoo, ochronosis).

CONCLUSION

RCM has been explored and proven valuable for the evaluation and management of pigmentary disorders including melasma, vitiligo, solar lentigines, tattoo, and tattoo-related complications.

Monitoring of Vitiligo Patches Over Six Months to Validate Dermoscopic Findings of Lesional Stability

INTRODUCTION

Previously laid down criteria for lesional stability of vitiligo are inconsistent. Longitudinal data on correlation between dermoscopic features of vitiligo and disease activity is limited.

OBJECTIVES

To sequentially determine the dermoscopic features of vitiligo and to assess their association with the dynamic nature of the vitiligo patch.

METHODS

Sixty patients with 200 vitiligo patches fulfilling the inclusion criteria on medical therapy were subjected to sequential clinical and dermoscopic examination for 6 months. Baseline lesional photographs, dermoscopy and tracing of the patch was made and repeated at 6 months. The follow up tracing was superimposed onto the baseline tracing. Based on the increase or decrease in size, their outcomes were grouped as responsive, progressive and quiescent. Paired analysis of dermoscopic features was done between baseline, and their follow up after 6 months.

RESULTS

Well defined border was associated with static nature of the vitiligo patch and ill-defined borders and trichrome pattern depicted its dynamic nature. Statistically significant increase in leukotrichia and satellite lesions amongst progressive patches and a decrease amongst responsive patches was observed. Pigment network changes were statistically significant for both responsive and progressive patches. Satellite lesions and micro-Koebner's phenomena was suggestive of progressive disease, while perifollicular pigmentation and perilesional hyperpigmentation was suggestive of re-pigmenting disease and proved to be an early marker for response to therapy.

CONCLUSIONS

Repeated dermoscopic evaluation of lesions in a serial manner to assess disease activity helps understand their evolving nature and is a valuable tool in planning appropriate further treatment.

Non-invasive Imaging Techniques for Monitoring Cellular Response to Treatment in Stable Vitiligo

Punch grafting procedures, where small pieces of normal skin are transplanted into stable vitiligo patches, results in repigmentation in only half of patients treated, yet the factors that determine whether a patient responds to treatment or not are still unknown. Reflectance confocal microscopy (RCM) is adept at visualizing melanocyte migration and epidermal changes over large areas while multiphoton microscopy (MPM) can capture metabolic changes in keratinocytes. With the overall goal of identifying optical biomarkers for early treatment response, we followed 12 vitiligo lesions undergoing punch grafting. Dendritic melanocytes adjacent to the graft site were observed before clinical evidence of repigmentation in treatment responsive patients but not in treatment non-responsive patients, suggesting that the early visualization of melanocytes is indicative of a therapeutic response. Keratinocyte metabolic changes in vitiligo skin adjacent to the graft site also correlated with treatment response, indicating that a keratinocyte microenvironment that more closely resembles normal skin is more hospitable for migrating melanocytes. Taken together, these studies suggest that successful melanocyte transplantation requires both the introduction of new melanocytes and modulation of the local tissue microenvironment.

Non-invasive skin measurement methods and diagnostics for vitiligo: a systematic review

Vitiligo is a multifaceted autoimmune depigmenting disorder affecting around 0.5 to 2.0% of individuals globally. Standardizing diagnosis and therapy tracking can be arduous, as numerous clinical evaluation methods are subject to interobserver variability and may not be validated. Therefore, there is a need for diagnostic tools that are objective, dependable, and preferably non-invasive.

Aims

This systematic review provides a comprehensive overview of the non-invasive objective skin measurement methods that are currently used to evaluate the diagnosis, severity, and progression of vitiligo, as well as the advantages and limitations of each technique.

Methods

The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) checklist was used for the systematic review. Scopus, Embase, Cochrane Library, and Web of Science databases were comprehensively searched for non-invasive imaging and biophysical skin measuring methods to diagnose, evaluate the severity of, or monitor the effects of vitiligo treatment. The risk of bias in included articles was assessed using the QUADAS-2 quality assessment scale.

Results

An extensive literature search resulted in 64 studies for analysis, describing eight imaging techniques (reflectance confocal microscopy, computer-aided imaging analysis, optical coherence tomography, infrared photography, third-harmonic generation microscopy, multiphoton microscopy, ultraviolet light photography, and visible light/digital photograph), and three biophysical approaches (dermoscopy, colorimetry, spectrometry) used in diagnosing and assessing vitiligo. Pertinent information about functionality, mechanisms of action, sensitivity, and specificity was obtained for all studies, and insights into the strengths and limitations of each diagnostic technique were addressed. Methodological study quality was adequate; however, statistical analysis was not achievable because of the variety of methods evaluated and the non-standardized reporting of diagnostic accuracy results.

Conclusions

The results of this systematic review can enhance clinical practice and research by providing a comprehensive overview of the spectrum of non-invasive imaging and biophysical techniques in vitiligo assessment. Studies with larger sample sizes and sound methodology are required to develop verified methods for use in future practice and research.

Systematic review registration

(PROSPERO) database, (CRD42023395996).

Enlarged rete pegs with excessive accumulation of melanosomes leading to darker aging spots revealed by histomorphological measurements of internal structures of the epidermis

OBJECTIVE

Various histological studies of facial pigmented spot sites such as solar lentigo have been reported, but few studies have used quantitative indices by histomorphometric analysis of the internal structure of pigmented spot sites using non-invasive methods. In the present study, to quantitatively elucidate morphological changes in the epidermis in male, darker-pigmented spots and female, light-pigmented spots, indices that characterize the internal structure of the epidermis in pigmented spot sites were measured using in vivo confocal laser scanning microscopy (CLSM).

METHODS

The darkness of pigmented spots on the cheeks of 69 women and 43 men was analysed using image analysis software. The L* value was calculated from RGB values obtained from facial images. The internal structures of pigmented spots on the cheeks of 13 subjects were observed by CLSM. Various parameters were measured using CLSM images from the surface of the stratum corneum to the bottom of the dermal papillae, including the thickness of the epidermis, melanosome content, and shape of the dermal papillae.

RESULTS

Mean ΔL* values between pigmented spots and non-pigmented areas of male subjects were significantly increased in the 40s and 50s compared with those of female subjects. Conspicuous pigmented spots increased in the 40s in male subjects and the 50s in female subjects. In CLSM observations, significant increases in the thickness of the epidermis and melanosome content were confirmed in pigmented spots compared with surrounding non-pigmented areas. In particular, melanosome content in the male subject group with dark-coloured pigmented spots increased significantly to about eight times that of non-pigmented areas, and more than double that of the male subject group with light-coloured pigmented spots.

CONCLUSION

From the measurements of quantitative parameters, morphological changes in the epidermis were clearly related to the surface colour tone of pigmented spots. Darker pigmented spot sites tended to show longer rete pegs in the epidermis. Accumulation of melanosomes in epidermal basal cells could be considered to increase with the degree of elongation of rete pegs at pigmented spot sites and, thus, induce darker pigmented spots.

Progress in the application of reflectance confocal microscopy in dermatology

Reflectance confocal microscopy (RCM) is abbreviated as skin three-dimensional computed tomography, which can help clearly observe the structure of the epidermis and superficial dermis. It is a non-invasive skin disease examination method and provides fast access to real-time, dynamic skin micro-anatomical images. Therefore, RCM is widely used in the clinical diagnosis of skin diseases. For example, the RCM features of vitiligo are as follows: pigment loss or partial pigment loss in the lesion area, loss of the basal layer pigment ring. The RCM findings of Riehl melanosis are as follows: basal cell liquefaction and degeneration. The RCM results for verruca plana show: the Rose-like structure. The characteristics of psoriasis under RCM include: hyperkeratosis, parakeratosis, thickening of the spinous layer, capillary dilatation and hyperaemia, peripheral inflammatory cell infiltration. Epidermal brain-like structure was observed under RCM of seborrheic keratosis. With RCM, image acquisition and preservation of the skin is convenient, and the technique is convenient for comparing the development of lesions during long-term follow-up observation. Therefore, it helps to understand disease development in real time and dynamically and can be used to evaluate the curative effect. In this article, we briefly review the technical principles, diagnostic criteria for RCM application and RCM-related research progress in the diagnosis of pigmentary diseases, inflammatory diseases, skin tumours, and other common skin diseases.

Vitiligo with Progressive Repigmentation during Secukinumab Treatment in a Patient with Psoriatic Arthritis: A Case Report

The proposed role of interleukin (IL)-17 in vitiligo pathogenesis, as well as the possible action of anti-IL-17A drugs on vitiligo, are not fully understood. The appearance of vitiligo as a paradoxical effect of treatment with anti-tumor necrosis factor-α drugs is an event well known in the literature, but is rarely described with anti-IL-17A drugs. In this case report, we describe a 42-year-old woman who developed new-onset vitiligo with repigmentation during successful secukinumab therapy for psoriatic arthritis. After 1 year of secukinumab therapy, vitiligo affecting >85% of the skin was evident on clinical and dermatoscopic examination, together with small, repigmented lesions. In depigmented lesions, reflectance confocal microscopy (RCM) showed disappearance of the bright dermal papillary rings normally seen at the dermo-epidermal junction. In repigmented lesions, activated dendritic melanocytes were observed on RCM. The patient continued to receive secukinumab, and continued to experience a slow and progressive repigmentation. Our case shows that anti-IL-17A biological agents for chronic inflammatory diseases may be associated with the development of new-onset vitiligo that improves over time with ongoing therapy. Therefore, physicians should be aware of the possibility of this rare paradoxical skin reaction in patients receiving secukinumab, and that it may not be necessary to discontinue secukinumab to achieve repigmentation.

Effect of reflectance confocal microscopy compared to dermoscopy in the diagnostic accuracy of lentigo maligna: A meta-analysis

INTRODUCTION

Many concerns were raised about the sensitivity and specificity outcome of reflectance confocal microscopy compared to dermoscopy for the diagnosis of lentigo maligna. However, the reported relationships between their sensitivity and specificity were variable. Our meta-analysis was performed to clarify this relationship.

METHODS

A systematic literature search up to July 2020 was performed and six included studies had 479 subjects at the baseline with 294 undergoing lentigo maligna diagnoses. They were reporting relationships between sensitivity and specificity outcome of reflectance confocal microscopy compared to dermoscopy for the diagnosis of lentigo maligna. Mean difference (MD) with 95% confidence intervals (CIs) was calculated to evaluate the prognostic role of the sensitivity and specificity of reflectance confocal microscopy compared to dermoscopy for the diagnosis of lentigo maligna using the continuous method with a random or fixed-effect model.

RESULTS

Reflectance confocal microscopy was significantly related to higher specificity (MD, 19.10; 95% CI, 0.93-37.28, P = .04) compared to dermoscopy in lentigo maligna diagnosis. However, reflectance confocal microscopy was only relatively but not significantly related to higher sensitivity (MD, 14.56; 95% CI, 0.29-28.83, P = .05) compared to dermoscopy in lentigo maligna diagnosis.

CONCLUSIONS

Based on this meta-analysis, the reflectance confocal microscopy compared to dermoscopy in lentigo maligna diagnosis had a significantly higher specificity and relatively higher sensitivity. This relationship forces us to recommend reflectance confocal microscopy in lentigo maligna diagnosis for better outcomes and to avoid any possible false-negative results. Further studies are required.

Clinical Applications of In Vivo and Ex Vivo Confocal Microscopy

Confocal laser scanning microscopy (CLSM) has been introduced in clinical settings as a tool enabling a quasi-histologic view of a given tissue, without performing a biopsy. It has been applied to many fields of medicine mainly to the skin and to the analysis of skin cancers for both in vivo and ex vivo CLSM. In vivo CLSM involves reflectance mode, which is based on refractive index of cell structures serving as endogenous chromophores, reaching a depth of exploration of 200 μm. It has been proven to increase the diagnostic accuracy of skin cancers, both melanoma and non-melanoma. While histopathologic examination is the gold standard for diagnosis, in vivo CLSM alone and in addition to dermoscopy, contributes to the reduction of the number of excised lesions to exclude a melanoma, and to improve margin recognition in lentigo maligna, enabling tissue sparing for excisions. Ex vivo CLSM can be performed in reflectance and fluorescent mode. Fluorescence confocal microscopy is applied for “real-time” pathological examination of freshly excised specimens for diagnostic purposes and for the evaluation of margin clearance after excision in Mohs surgery. Further prospective interventional studies using CLSM might contribute to increase the knowledge about its application, reproducing real-life settings.

The Differential Diagnosis of Hypopigmented Mycosis Fungoides and Vitiligo With Reflectance Confocal Microscopy: A Preliminary Study

Objective: To investigate the role of reflectance confocal microscopy (RCM) in the differential diagnosis of hypopigmented mycosis fungoides (HMF) and vitiligo.

Methods: Cases with persistent hypopigmented patches, suspicious of early stage vitiligo, or HMF were imaged with RCM. The melanin contents and inflammatory conditions of the epidermis and superficial dermis of the lesions were compared with the same layers of the adjacent skin, and then, the imaged lesions were biopsied and analyzed by histology.

Results: 15 cases were enrolled in this study, and based on the RCM findings, there was just slight or moderate reduction of melanin but no melanin absence in the basal cell layer of HMF lesions. The finding of monomorphous weakly refractile, oval to round cells on the basis of vesicle-like dark space was clearly elucidated in the epidermis of the lesions by RCM, which indicates the Pautrier's microabscesses on histopathology. Among those 15 cases, 13 cases were identified as HMF, and the other two cases were vitiligo, based on RCM findings, which were confirmed by histology analysis.

Conclusions: The RCM findings correlated well with histology results in the screening of HMF, which indicates the RCM is an important tool in the early detection and differential diagnosis of HMF.

Vitiligo: A Review

Vitiligo, a common depigmenting skin disorder, has an estimated prevalence of 0.5–2% of the population worldwide. The disease is characterized by the selective loss of melanocytes which results in typical nonscaly, chalky-white macules. In recent years, considerable progress has been made in our understanding of the pathogenesis of vitiligo which is now clearly classified as an autoimmune disease. Vitiligo is often dismissed as a cosmetic problem, although its effects can be psychologically devastating, often with a considerable burden on daily life. In 2011, an international consensus classified segmental vitiligo separately from all other forms of vitiligo, and the term vitiligo was defined to designate all forms of nonsegmental vitiligo. This review summarizes the current knowledge on vitiligo and attempts to give an overview of the future in vitiligo treatment.

A meta-analysis comparing confocal microscopy and dermoscopy in diagnostic accuracy of lentigo maligna

PURPOSE

We aimed to summarize the sensitivity and specificity between RCM and dermoscopy in LM diagnosis.

METHODS

A meta-analysis was conducted to the study. PubMed, Google Scholar, Cochrane Library, and Wiley Online Library database were searched for relevant studies. The basic information of the patients, sensitivity, and specificity were calculated. I2 was used for the assessment of the heterogeneity. A random-effect model was used for analyzing the data of the literature study.

RESULTS

A total of 498 patients from 7 articles were included in the study. The articles summarized the sensitivity and specificity between RCM and dermoscopy in the treatment of lentigo maligna. The overall sensitivity of RCM was 0.93, and the overall specificity was 0.89. RCM diagnostic odds ratio (DOR) was 104.38, RCM positive likelihood (+LR/PLR) was 8.50, and the negative LR (-LR/NLR) was 0.08. The overall sensitivity of dermoscopy was 0.73 (95% CI: 0.58-0.84), and the overall specificity was 0.84 (95% CI: 0.71-0.92). The DOR, +LR, and -LR of dermoscopy were 14.48, 4.65, and 0.32, respectively.

CONCLUSION

RCM has a better accuracy than dermoscopy in the diagnosis of LM.

Aquaporin 3 and E-Cadherin Expression in Perilesional Vitiligo Skin

INTRODUCTION

Vitiligo is a common dermatologic disorder with debated aetiology. Most studies focused on role of melanocytes and few investigated the role of keratinocytes in pathogenesis of the disease.

AIM

To investigate the keratinocyte adhesion in perilesional vitiligo skin through the immunolocalization of Aquaporin-3 (AQP3) and E-cadherin.

SETTING AND DESIGN

Sixty five subjects were selected. These included 40 cases with vitiligo and 25 age and gender-matched healthy subjects as a control group.

MATERIALS AND METHODS

Skin biopsies were taken from perilesional skin of cases and from site-matched areas of control subjects. The expression of AQP3 and E-cadherin was evaluated by immunohistochemical techniques.

STATISTICAL ANALYSIS

Results were statistically analysed using IBM personal computer and the statistical package SPSS version 11. Fisher-exact and Chi-square tests were used to study the association between two qualitative variables. Mann-Whitney test was used for comparison between quantitative variables not normally distributed. Spearman's correlation coefficient was used to assess correlation between two quantitative variables. The p≤0.05 was considered significant.

RESULTS

Regarding AQP3 expression, strong intensity, diffuse distribution, higher percent of expression and higher H-score (p<0.001 for all) were significantly associated with control skin compared with perilesional skin in follicular and inter-follicular epidermis. Regarding E-cadherin expression, moderate intensity, higher percent of expression and higher H- score (p<0.001 for all) were significantly associated with control skin compared with perilesional skin in follicular and inter-follicular epidermis. No significant association was found between E-cadherin and AQP3 H-scores or percent of expression and clinical data of selected cases. No significant correlation was detected between E-cadherin and AQP3 H-scores or percent of expression and age of cases, disease duration or Vitiligo Disease Activity (VIDA) score.

CONCLUSION

The following sequence of events can be suggested for vitiligo pathogenesis, based on findings in perilesional skin: AQP3 is downregulated by a primary unknown factor and this will lead to down regulation of its downstream molecules, mainly phosphatidylinositol 3-kinase, E-cadherin and catenins, which is followed by defective keratinocyte adhesion and decreased release of keratinocyte-derived growth factors. Subsequently a secondary event, physical trauma, oxidative stress or autoantibodies, may lead to exfoliation of keratinocytes and pigmented cells.

Is Lesional Stability in Vitiligo More Important Than Disease Stability for Performing Surgical Interventions? Results from a Multicentric Study

Background:

Ensuring stability of the disease process is essential for undertaking surgical intervention in vitiligo. However, there is no consensus regarding the minimum duration of stability or the relative importance of disease and lesional stability in selecting patients for vitiligo grafting.

Aim:

This multicentric study aims to assess the relative importance of lesional and disease stability on selecting patients for vitiligo grafting.

Materials and Methods:

One hundred seventy patients were recruited into the study and divided into two groups: Group A with lesional stability of >1 year but overall disease stability of only 6-11 months and Group B with overall disease stability of >1 year. Patients underwent either tissue or cellular vitiligo grafting on the selected lesions and the repigmentation achieved was scored from 0 (no repigmentation) to 6 (100% repigmentation). Repigmentation achieved on different sites of the body was compared between the two groups. Adverse effects at both the donor and the recipient sites were also compared.

Results:

Of the 170 patients who were enrolled, 82 patients were placed in Group A and 88 patients in Group B. Average repigmentation achieved (on scale of 0 to 6) was 3.8 and 4.04 in Group A and Group B, respectively. In Group A, ≥90% repigmentation was achieved in 36.6% (30/82) patients, while 37.5% (33/88) achieved similar results in Group B. Additionally, 47.6% (39/82) and 53.4% (47/88) of cases achieved partial repigmentation in Group A and Group B, respectively. Perigraft halo was the commonest adverse effect observed in both groups. Statistical analysis revealed no significant differences between the two groups with respect to the repigmentation achieved or adverse effects observed. Repigmentation achieved was the best on the face and neck area, while acral areas responded the least.

Conclusions:

Lesional stability seems to be as relevant as the overall disease stability in selecting patients for surgical intervention in vitiligo.

[Confocal laser scanning microscopy]

Reflectance confocal microscopy (RCM) allows the in vivo evaluation of melanocytic and nonmelanocytic skin tumours with high sensitivity and specificity. RCM represents an optical imaging technique, which enables us to examine the skin at high resolution. Today, RCM represents not only an interesting tool for dermatologic research but has also been introduced as a diagnostic tool in every day clinical practice. As such, RCM is applied for improvement of skin cancer diagnosis adjunct to clinical and dermatoscopic examination. In combination with dermatoscopy RCM has shown an increased specificity with similar sensitivity. In this regard RCM helps to decrease the rate of unnecessary biopsies of benign lesions. Despite its use in dermatooncology RCM may also be used for diagnosis and monitoring of inflammatory diseases. Future developments include technical improvements, teledermatology solutions and the application of ex vivo RCM in Moh's micrographic surgery.

Real-time in vivo confocal laser scanning microscopy of melanin-containing cells: A promising diagnostic intervention

The use of noninvasive imaging techniques to evaluate different types of skin lesions is increasing popular. In vivo confocal laser scanning microscopy (CLSM) is a new method for high resolution non-invasive imaging of intact skin in situ and in vivo. Although many studies have investigated melanin-containing cells in lesions by in vivo CLSM, few studies have systematically characterized melanin-containing cells based on their morphology, size, arrangement, density, borders, and brightness. In this study, the characteristics of melanin-containing cells were further investigated by in vivo CLSM. A total of 130 lesions, including common nevi, giant congenital pigmented nevi, vitiligo, melasma, melanoma, and chronic eczema, were imaged by in vivo CLSM. This research helps dermatologists understand the characteristics of melanin-containing cells and facilitate the clinical application of melanin-containing cells in the investigation of dermatological disease. In summary, melanin-containing cells include keratinocytes, melanocytes, macrophages, and melanocytic skin tumor cells. Our study presents the CLSM characteristics of melanin-containing cells to potentially facilitate in vivo diagnosis based on shape, size, arrangement, density, borders, and brightness.

A New View of Vitiligo: Looking at Normal-Appearing Skin

Debate over the pathogenesis of vitiligo is still ongoing among scientists, with several hypotheses currently under consideration. The study by Wagner et al. in this issue focuses on the role of E-cadherin-mediated cell adhesion in vitiliginous epidermis under oxidative and mechanical stress. Their work highlights how alterations in cell-cell adhesion across nonlesional melanocyte membranes in patients with vitiligo argue for primary intrinsic defects in the melanocytes.

Stability in Vitiligo: Is there a Perfect Way to Predict it?

Stability is a hard-to-define concept in the setting of vitiligo, but is nonetheless extremely crucial to the planning of treatment regimens and also in prognosticating for the patient. There are several ways to judge stability in vitiligo, which include clinical features and, recently, many biochemical, cytological and ultrastructural correlates of the same. These recent advances help in not only in prognosticating individual patients but also in elucidating some of the mechanisms for the pathogenesis of vitiligo, including melanocytorrhagy and oxidative damage to melanocytes.

Concordance between in vivo reflectance confocal microscopy and optical histology of lymphomatoid papulosis

BACKGROUND

Lymphomatoid papulosis is a primary cutaneous CD30+ T-cell lymphoma clinically characterized by a benign, chronic, recurrent course with self-limited papulo-nodular skin lesion eruption. In vivo Reflectance Confocal Microscopy is a non-invasive technique for real-time imaging of the superficial layers of the skin down to the superficial dermis with cellular-level resolution close to conventional histopathology. RCM has been previously reported to be useful in the in vivo evaluation of inflammatory diseases, skin tumours and also cutaneous lymphomas. Only two articles have been published on cutaneous lymphomas and none detailing confocal features of LyP. The aim of this manuscript was to describe the confocal features of LyP and their histological correlation to evaluate the possible application of this non-invasive tool in this T-cell lymphoma subtype clinical management.

METHODS

Five patients with histological diagnosis of LyP were imaged with RCM, followed by a skin biopsy on a clinically selected lesion.

RESULTS

High grade of correspondence between RCM and histopathology of LyP was observed, disclosing the potential rule of RCM at least for biopsy site selection.

CONCLUSION

Future studies on RCM for LyP vs. other cutaneous T-cells lymphomas and inflammatory skin diseases are needed to assess specificity and sensibility of our preliminary data.

Assessment methods for the evaluation of vitiligo

There is no standardized method for assessing vitiligo. In this article, we review the literature from 1981 to 2011 on different vitiligo assessment methods. We aim to classify the techniques available for vitiligo assessment as subjective, semi-objective or objective; microscopic or macroscopic; and as based on morphometry or colorimetry. Macroscopic morphological measurements include visual assessment, photography in natural or ultraviolet light, photography with computerized image analysis and tristimulus colorimetry or spectrophotometry. Non-invasive micromorphological methods include confocal laser microscopy (CLM). Subjective methods include clinical evaluation by a dermatologist and a vitiligo disease activity score. Semi-objective methods include the Vitiligo Area Scoring Index (VASI) and point-counting methods. Objective methods include software-based image analysis, tristimulus colorimetry, spectrophotometry and CLM. Morphometry is the measurement of the vitiliginous surface area, whereas colorimetry quantitatively analyses skin colour changes caused by erythema or pigment. Most methods involve morphometry, except for the chromameter method, which assesses colorimetry. Some image analysis software programs can assess both morphometry and colorimetry. The details of these programs (Corel Draw, Image Pro Plus, AutoCad and Photoshop) are discussed in the review. Reflectance confocal microscopy provides real-time images and has great potential for the non-invasive assessment of pigmentary lesions. In conclusion, there is no single best method for assessing vitiligo. This review revealed that VASI, the rule of nine and Wood's lamp are likely to be the best techniques available for assessing the degree of pigmentary lesions and measuring the extent and progression of vitiligo in the clinic and in clinical trials.

Histological classification of melasma with reflectance confocal microscopy: a pilot study in Chinese patients

OBJECTIVE

To investigate the histological classification of melasma with reflectance confocal microscopy (RCM) in vivo.

METHODS

Two hundred and ten cases with facial melasma lesions were enrolled. After informed consent, the target melasma lesion of 10 patients were imaged with RCM and then biopsied as well. Under the RCM scanning, the distribution of the melanin determined the histological types, and then, the results of RCM images were compared with those of the histopathology. The other 200 cases were tested only with RCM.

RESULTS

For the 10 cases imaged and biopsied, compared with that of the perilesional normal skin, the amount of melanin was significantly increased in the epidermis in all lesions under RCM, while three cases also found melanin in the dermis. Thus, seven of the 10 patients were categorized as the epidermal type while the other three as mixed ones, and the results were well correlated with those of the histopathology. Of the other 200 patients, 143 cases 71.5%) were categorized as the epidermal type while the other 57 (28.5%) cases as mixed ones.

LIMITATIONS

If more melasma cases are biopsied, the data will be more convincing.

CONCLUSION

RCM in vivo analysis shows complete coherence with histopathology results, which could be an alternative for the classification of melasma, and based on the results of RCM imaging, melasma is classified into two major types: the epidermal type and mixed type.

Epidermal permeability barrier recovery is delayed in vitiligo-involved sites

BACKGROUND/OBJECTIVES

Prior studies have demonstrated that both the skin surface pH and epidermal permeability barrier function vary with skin pigmentation types. Although melanin deficiency is the main feature of vitiligo, alterations in cutaneous biophysical properties in vitiligo have not yet been well defined. In the present study, stratum corneum (SC) hydration, the skin surface pH and epidermal permeability barrier function in vitiligo were evaluated.

METHODS

A total of 30 volunteers with vitiligo comprising 19 males and 11 females aged 13-51 years (mean age: 27.91 +/- 2.06 years) were enrolled in this study. The skin surface pH, SC hydration, melanin/erythema index and transepidermal water loss (TEWL) were measured by respective probes connected to a Courage-Khazaka MPA5. SC integrity was determined by measuring the TEWL following each D-Squame application. The barrier recovery rate was assessed at 5 h following barrier disruption by repeated tape stripping.

RESULTS

In addition to SC hydration, both melanin and erythema index were significantly lower in vitiligo lesions than in contralateral, nonlesional sites, while no difference in skin surface pH between vitiligo-involved and uninvolved areas was observed. In addition, neither the basal TEWL nor SC integrity in the involved areas differed significantly from that in the uninvolved areas. However, barrier recovery in vitiligo-involved sites was significantly delayed in comparison with uninvolved sites (40.83 +/- 5.39% vs. 58.30 +/- 4.71%; t = 2.441; p < 0.02).

CONCLUSION

Barrier recovery following tape stripping of the SC is delayed in vitiligo. Therefore, improvement in epidermal permeability barrier function may be an important unrecognized factor to be considered in treating patients with vitiligo.

Reflectance confocal microscopy for pigmentary disorders

In vivo reflectance confocal microscopy (RCM) is a non-invasive, repetitive imaging tool that provides real-time images at nearly cellular histological resolution. Application of this technology to skin imaging during the last decade has been a great advance in dermatology. As melanin is the strongest endogenous contrast in human skin, pigmentary disorders caused by abnormal amounts of melanin in the skin could be the most suitable candidates for RCM examination. This article reviewed the RCM applications in the characterization and management of pigmentary disorders. The application of RCM in pigmentary disorders has been expanded to describe hyper- and hypopigmentary disorders as well as pigmented skin tumors. The great advantages of non-invasive and repetitive examination of RCM may provide its usefulness not only in the diagnosis and management of pigmentary disorders, but also in researching pathogenesis of pigmentary disorders.