In-depth study of Wood's lamp examination combined with reflective confocal laser scanning microscopy for the guidance of vitiligo staging and treatment.

BACKGROUND: Both Wood's lamp and reflective confidential laser scanning microcopy are helpful for the diagnosis and treatment of vitiligo. However, there is few research that contains large samples and consistent observations. AIMS: To analyze the characteristics of Wood's lamp images and reflectance confocal microscopy (RCM) images of vitiligo lesions and to evaluate their significance in vitiligo staging. METHODS: We analyzed the characteristics of RCM images, Wood's lamp images, the vitiligo disease activity (VIDA) score, and clinical features to guide vitiligo staging and treatment. RESULTS: The expert consensus based on the clinical features, VIDA score, Wood's lamp findings, and isomorphic response was consistent with the Wood's lamp findings (χ2 = 3.63, p > 0.05) and RCM findings (χ2 = 3.60, p > 0.05) in diagnosing vitiligo and assessing the disease stage. There was a correlation between the three lesion grades based on the Wood's lamp findings and the stage of vitiligo (p < 0.01). Lesions that appeared porcelain white under the Wood's lamp were in the slowly progressive stage; lesions that appeared gray-white or trichromatic under the Wood's lamp were in the rapidly progressive stage; lesions with clear borders under the Wood's lamp needed further analysis by RCM for the stage to be determined; lesions with blurred borders under the Wood's lamp were in the rapidly progressive stage; lesions that were visible under the naked eye and under the Wood's lamp were in the rapidly progressive stage. CONCLUSION: The study demonstrates a reliable correlation between the findings of RCM (a sophisticated expensive tool) and Wood's lamp examination (a simple, readily available, inexpensive tool) in the assessment of the disease activity of vitiligo lesions.

Bridging the Gap Between Vitiligo Segmentation and Clinical Scores.

Quantitative evaluation of vitiligo is crucial for assessing treatment response. Dermatologists evaluate vitiligo regularly to adjust their treatment plans, which requires extra work. Furthermore, the evaluations may not be objective due to inter- and intra-assessor variability. Though automatic vitiligo segmentation methods provide an objective evaluation, previous methods mainly focus on patch-wise images, and their results cannot be translated into clinical scores for treatment adjustment. Thus, full-body vitiligo segmentation needs to be developed for recording vitiligo changes in different body parts of a patient and for calculating the clinical scores. To bridge this gap, the first full-body vitiligo dataset with 1740 images, following the international vitiligo photo standard, was established. Compared with patch-wise images, full-body images have more complicated ambient light conditions and larger variances in lesion size and distribution. Additionally, in some hand and foot images, skin can be fully covered by either vitiligo or healthy skin. Previous patch-wise segmentation studies completely ignore these cases, as they assume that the contrast between vitiligo and healthy skin is available in each image for segmentation. To address the aforementioned challenges, the proposed algorithm in this study exploits a tailor-made contrast enhancement scheme and long-range comparison. Furthermore, a novel confidence score refinement module is proposed to manage images fully covered by vitiligo or healthy skin. Our results can be converted to clinical scores and used by clinicians. Compared to the state-of-the-art method, the proposed algorithm reduces the average per-image vitiligo involvement percentage error from 3.69% to 1.81%, and the top 10% per-image errors from 23.17% to 8.29%. Our algorithm achieves 1.17% and 3.11% for the mean and max error for the per-patient vitiligo involvement percentage, which is better than an experienced dermatologist's naked-eye evaluation.

Poisson-based image editing for semi-supervised vitiligo lesion segmentation with limited annotations.

Vitiligo lesion segmentation is crucial for the assessment and treatment of vitiligo. There are two significant challenges in this problem, namely, the availability of dense segmentation annotations and the collection of large amounts of vitiligo images, which are also major challenges in medical image analysis (MIA). However, most existing methods often heavily rely on the availability of large-scale labeled datasets and high-quality annotations. Consequently, the performance of these models may not be easily reproducible or transferable to those domains with limited data availability. As a result, there is a need to develop alternative approaches that can leverage unlabeled datasets for segmentation with a small-scale training set. In this paper, we propose a data augmentation strategy based on image editing, which can synthesize a large number of samples using a small number of annotated data. The synthesized examples are of high visual quality and enforce the segmentation performance without any cost. Besides, we also adapt the Mean-Teacher framework for reliable predictions mining from unlabeled samples to alleviate the demands of densely annotated segmentations. We obtain pseudo-labels for unlabeled samples by utilizing highly confident pixels. On the other hand, we proposed a new Bimodal Vitiligo Lesions Segmentation (BVLS) dataset containing fine-grain segmentation masks and bimodal images usually used for vitiligo diagnosis to mitigate the lack of a vitiligo segmentation dataset. Extensive experiments conducted on the BLVS dataset demonstrate that our approach can achieve significant improvements (+17.27%) compared with previous data augmentation methods on the UNet backbone. Furthermore, the semi-supervised framework can reach an IoU of 49.71% with only 10% annotated images. Our code and dataset are availabel at https://github.com/JcWang20/BLVS.

Novel ultraviolet-dermoscopy: Early diagnosis and activity evaluation of vitiligo.

BACKGROUND/OBJECTIVE: Polarized dermoscopy, Wood's lamp, and reflectance confocal microscopy were currently commonly used auxiliary technology in vitiligo clinic diagnosis. To improve the efficiency and accuracy of different periods of lesions of vitiligo, we used a novel ultraviolet (UV)-dermoscopy (Model CH-UVDS30, Ultraviolet wavelength range of 360<390nm, Chuanghong Science and Technology Company, China) in clinical observation. MATERIALS AND METHODS: Three cases of different periods of vitiligo patients were included in this study. Polarised dermoscopy and novel UV-dermoscopy (UV wavelength range of 360 nm < λ < 390 nm) were performed at 20 × magnification in polarized and UV modes. Characteristic manifestations of different periods of vitiligo lesions were captured and compared. RESULTS: The depigmented and pigmented junctional zone and perifollicular pigmentation areas could be easier and simultaneously identified via UV-dermoscopy. In a progressive vitiligo patient (woman, 42 years old, face) enhanced perifollicular pigmentation and blurred border were clearly observed. In a stable vitiligo patient (man, 27 years old, right foot) sharply demarcated border and perifollicular depigmentation could be found. In a re-pigmenting vitiligo patient (woman, 41 years old, neck) telangiectasias and pigmentation reservoirs were observed. CONCLUSION: Novel UV-dermoscopy, as a miniature and portable device, might help early diagnosis, active/progress judgment, and treatment effect evaluation of vitiligo in the clinic.

Reflectance Confocal Microscopy for Identification of Vulvar Lichen Sclerosus et Atrophicus and Vitiligo.

ABSTRACT: Lichen sclerosus et atrophicus (LSA) is a chronic inflammatory disease. The clinical presentation is clustered distribution of porcelain white spots that can be fused together. Early diagnosis of LSA is difficult, especially in the vulva, where it is difficult to distinguish from vitiligo. Traditional diagnostic methods mainly rely on histopathology. In this study, we used reflectance confocal microscopy (RCM) to study the characteristics of LSA and vitiligo. We investigated the clinical and confocal features of 40 cases of histopathologically proven genital LSA or vitiligo, and correlated the features with histopathologic findings. Through the analysis of the results, by RCM, we can easily distinguish genital LSA from vitiligo, which are clinically indistinguishable. This can reduce the number of unnecessary biopsies, and help with early diagnosis and timely treatment.

Image analysis systems to calculate the surface area of vitiligo lesions: A systematic review of measurement properties.

Several digital image analysis systems have been developed for surface calculation of vitiligo lesions. Critical assessment of their measurement properties is crucial to support evidence-based recommendations on the most suitable instruments and will reveal the need for future research. A systematic review was performed to systematically summarize, compare, and critically assess the measurement properties of digital and analogue analysis systems for surface calculation of vitiligo lesions following the Consensus-Based Standards for the Selection of Health Measurement Instruments (COSMIN) recommendations. Nineteen clinical trials were selected including 25 different instruments. Manual tracing on transparent sheets (contact planimetry) combined with digital measurement or point counting can be considered as the best validated method for the evaluation of target lesions taking into account the skin curvatures. Two-dimensional digital imaging analysis on photographs seems also robust although confirmatory data of different research groups using the same digital instrument in a wide range of skin types are missing. Analysis based on 3D photography is still in its early stage but is promising for whole-body analysis. However, the reported data on the quality of the instruments for surface area calculation of vitiligo lesions were in general rather limited. Therefore, future high-quality validation studies are required also including full body evaluations.

Differentiating active from stable vitiligo: The role of dermoscopic findings and their relation to CXCL10.

BACKGROUND: Distinguishing vitiligo activity/stability status is pivotal in the management of patients with vitiligo. CXCL10 is a chemokine released in the tissues and sera of patients with vitiligo and an indicator of disease activity. AIM: This study aimed to assess the role of dermoscopy in detecting active and stable vitiligo by comparing the dermoscopic signs in vitiligo with Vitiligo Disease Activity Score (VIDA), clinical activity, and CXCL10 activity. METHODS: Ninety-seven patients with vitiligo were enrolled in this cross-sectional study. Vitiligo activity/stability was assessed using VIDA scores, clinical examination, dermoscopy, and serum CXCL10 levels measured by enzyme-linked immunosorbent assay technique. Dermoscopic scores were calculated using BPLeFoSK score. RESULTS: The dermoscopic score was concordant with the VIDA score in 83.5% of patients (n = 81), clinical assessment in 97.9% (n = 95), and serum CXCL10 level in 70.1% (n = 68). Dermoscopic signs of ill-defined border, satellite lesions, and micro-Koebner and starburst appearance were more common in active vitiligo, while a well-defined border was more common in stable lesions. CONCLUSION: Dermoscopic examination is a practical, reliable, noninvasive, semi-objective tool in the assessment of vitiligo activity/stability that helps reach an informed decision on the disease status to choose the appropriate therapeutic modality.

Design and Implementation of a Heating Treatment System for Vitiligo Skin Disease Based on Medical Ultrasound.

Vitiligo is relatively common clinically. It is an acquired and persistent skin and mucosal pigment depigmentation disease. As a noninvasive and nonradioactive treatment, high-energy ultrasound has been applied to skin diseases of vitiligo. Treatment achieved good clinical results. This article analyzes the structure of the original medical ultrasound system for vitiligo and finds the deficiencies and missing components of the system. On the basis of the original design scheme, a new structural scheme was designed, which solved the shortcomings of the original system and added missing parts. Subsequently, according to actual application requirements and specific component performance, the schematic design, including audio and video input, output and storage, DDR3, Ethernet, and the design of key circuits, such as power supply modules, are specifically introduced. Later, in the PCB design, the contents including stacking, layout, routing, and simulation of key signals were introduced in detail. The design includes a probe excitation signal generation module, excitation signal parameter control module, high voltage and temperature monitoring module, and corresponding power conversion module. This paper is mainly to develop a vitiligo skin disease heating treatment array system based on the principle of both cost and performance. This paper is based on the nonrigid registration algorithm of the FFD model and HPV interpolation and the nonrigid registration algorithm combining shape information and SIFT method. In the focused ultrasound treatment system, the image-guided positioning and monitoring functions are realized. Studies have shown that when the peak voltage of the transmitter circuit is 55 V, the sound power is 0.28 W. It can be seen that the transmitting circuit system designed in this article is a relatively stable and reliable system, which is suitable for the ultrasound treatment of vitiligo skin diseases.

Segmenting Vitiligo on Clinical Face Images Using CNN Trained on Synthetic and Internet Images.

Accurately diagnosing and describing the severity of vitiligo is crucial for prognostication, treatment selection and comparison. Currently, disease severity scores require dermatologists to estimate percentage area of involvement, which is subjected to inter and intra-assessor variability. Previous studies focus on pure skin but vitiligo on the face, which has a more serious impact on patients' quality of life, was completely neglected. Convolutional neural networks (CNNs) have good performance on many segmentation tasks. However, due to data privacy, it is hard to have a large clinical vitiligo face image dataset to train a CNN. To address this challenge, images from two different sources, the Internet and the proposed vitiligo face synthesis algorithm, are employed in training. 843 vitiligo images taken from different viewpoints were collected from the Internet. These images are hugely different from the target clinical images collected according to a newly established international standard. To have more vitiligo face images similar to the target clinical images to enhance segmentation performance, an image synthesis algorithm is proposed. Both synthetic and Internet images are used to train a CNN which is modified from the fully convolutional network (FCN) to segment face vitiligo lesions. The results show that 1) the synthetic images effectively improve segmentation performance; 2) the proposed algorithm achieves 1.06 % error for the face vitiligo area estimation and 3) it is more accurate than two dermatologists and all the previous automated vitiligo segmentation methods, which were designed for segmentation vitiligo on pure skin.

Proposing a novel unsupervised stack ensemble of deep and conventional image segmentation (SEDCIS) method for localizing vitiligo lesions in skin images.

BACKGROUND: Vitiligo is an acquired pigmentary skin disorder characterized by depigmented macules and patches which brings many challenges for the patients suffering from. For vitiligo severity assessment, several scoring methods have been proposed based on morphometry and colorimetry. But, all methods suffer from much inter- and intra-observer variations for estimating the depigmented area. For all mentioned assessment methods of vitiligo disorder, accurate segmentation of the skin images for lesion detection and localization is required. The image segmentation for localizing vitiligo skin lesions has many challenges because of illumination variation, different shapes and sizes of vitiligo lesions, vague lesion boundaries and skin hairs and vignette effects. The manual image segmentation is a tedious and time-consuming task. Therefore, using automatic image segmentation methods for lesion detection is necessarily required. MATERIALS AND METHODS: In this study, a novel unsupervised stack ensemble of deep and conventional image segmentation (SEDCIS) methods is proposed for localizing vitiligo lesions in skin images. Unsupervised segmentation methods do not require prior manual segmentation of vitiligo lesions which is a tedious and time-consuming task with intra- and inter-observer variations. RESULTS: Our collected dataset includes 877 images taken from 21 patients with the resolution of 5760*3840 pixels suffering from vitiligo disorder. Experimental results show that SEDCIS outperforms the compared methods with accuracy of 97%, sensitivity of 98%, specificity of 96%, area overlapping of 94%, and Dice index of 97%. CONCLUSION: The proposed method can segment vitiligo lesions with highly reasonable performance and can be used for assessing the vitiligo lesion surface.

Retinal nerve fiber layer, retinal pigment epithelium, and choroidal thickness in vitiligo patients.

BACKGROUND: Vitiligo is one of the common pigmentary disorders affecting the ocular structures. AIM: To determine the retinal nerve fiber layer (RNFL), retinal pigment epithelium (RPE), and choroidal thickness (CT) in vitiligo patients and to evaluate the relationship between choroidal thickness and vitiligo subtypes. METHODS: The right eyes of 106 participants (51 vitiligo, 55 nonvitiligo) were included in the study. All of the participants underwent detailed eye examinations and spectral-domain optical coherence tomography (SD-OCT) examinations. CT was measured manually with enhanced depth imaging optical coherence tomography (Edi-OCT) (subfoveal [SubF], nasal n500 µm [N1], n1500 µm [N2]), and temporal (t500 µm [T1], t1500 µm [T2]). RESULTS: In vitiligo patients, CT values were significantly lower in the SubF, N1, N2, T1, and T2 areas compared to the control group (P = .001, P = .011, P = .002, P = .005, P Ë‚ .001, respectively). Periorbital involvement did not affect CT (P = .355, P = .746, P = .443, P = .633, P = .558, respectively). However, in patients with periorbital region involvement, the CT was significantly reduced if the lesion had a universal character (P Ë‚ .001, P = .001, P = .011, P Ë‚ .001, P = .002, respectively). It was observed that RPE thickness decreased in vitiligo, but this difference was not statistically significant (P = .140). RNFL thickness was unaffected in all quadrants. A positive correlation (r = .286, r = .280, respectively) was observed between the Vitiligo Area Severity Index (VASI) and age and disease duration. A negative correlation (r = -.360, r = -.316, r = -.315, r = -.313, respectively) was found in the CT of the SubF, N1, N2, T1, and T2 areas. CONCLUSION: Vitiligo patients should be closely monitored for possible posterior ocular segment disorders.

In vivo third-harmonic generation microscopy study on vitiligo patients.

Melanin is known to provide strong third-harmonic generation (THG) contrast in human skin. With a high concentration in basal cell cytoplasm, THG contrast provided by melanin overshadows other THG sources in human skin studies. For better understanding of the THG signals in keratinocytes without the influence of melanin, an in vivo THG microscopy (THGM) study was first conducted on vitiliginous skin. As a result, the THG-brightness ratio between the melanin-lacking cytoplasm of basal cells and collagen fibers is about 1.106 at the dermal-epidermal junctions of vitiliginous skin, indicating high sensitivity of THGM for the presence of melanin. We further applied the in vivo THGM to assist evaluating the therapeutic outcome from the histopathological point of view for those showed no improvement under narrowband ultraviolet B therapy based on the seven-point Physician Global Assessment score. Our clinical study indicates the high potential of THGM to assist the histopathological assessment of the therapeutic efficacy of vitiligo treatments.

UV light set-ups for vitiligo photography, a comparative study on image quality and ease of use.

BACKGROUND: Ultraviolet (UV) light is an essential tool to assess the extent, spreading and staging of vitiligo. Different UV light set-ups are used for vitiligo photography, including the following: (i) hand-held Wood's lamps; (ii) soft boxes with UV lamps; (iii) UV flash attached to the camera; and (iv) high output UV flash. OBJECTIVE: Our objective was to compare UV light set-ups for vitiligo photography regarding image quality and ease of use. METHODS: Patients with vitiligo lesions with unclear borders were included. Two images were made with all four UV set-ups per patient, for a large and a small area. Image quality was scored separately by three blinded vitiligo experts on five criteria: overall quality, clearness of borders, contrast and sharpness and for larger areas the shadows. The two professional medical photographers were asked to score the ease of use for each set-up. RESULTS: A total of 88 photos were assessed from 11 patients. For larger areas, the frequency of a 'good' or 'very good' overall quality rating was 12.1% (Wood's), 6.1% (soft boxes), 15.2% (camera flash) and 78.8% (high output flash). For smaller areas, the score 'good' or 'very good' was given to 54.5%, 3%, 66.6% and 84.8% in the same order. For the shadow criteria, each set-up scored below 40% on a 'good' or 'very good' score. The high output flash was scored as most easy to use by the photographers. CONCLUSION: When comparing four different UV light set-ups for vitiligo photography, we concluded that the UV set-ups strongly influenced the quality scores of the obtained images. The high output flash scored best for both small and large areas and for ease of use. For small areas, Wood's lamp and camera flash were acceptable. All set-ups scored badly for shadows, and more research is needed to find the optimal exposure to avoid shadows.