In vivo reflectance confocal microscopy for the differential diagnosis between vitiligo and nevus depigmentosus

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.

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).

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.

Clinical differences between segmental nevus depigmentosus and segmental vitiligo

Segmental nevus depigmentosus and segmental vitiligo can be difficult to differentiate from each other. Differential diagnosis of these two diseases is important because they have significantly different prognoses and psychological effects. The purpose of this study is to identify clinical clues that may be helpful in differentiating these two diseases. We enrolled 63 patients with segmental nevus depigmentosus and 149 patients with segmental vitiligo. Sex, age of onset, sites involved, dermatomal distribution, margin of lesion and presence of poliosis were evaluated in both groups. The age of onset was less than 10 years in 96.8% of segmental nevus depigmentosus and 28.9% of segmental vitiligo cases. Trunk (36.5%) and cervical (38.1%) dermatomes were the most commonly involved in segmental nevus depigmentosus and face (67.1%) and trigeminal (64.4%) dermatomes in segmental vitiligo. The average number of dermatomes involved in truncal lesions was different in segmental nevus depigmentosus and segmental vitiligo (2.71 vs 1.62, P = 0.001). Segmental vitiligo on the face, neck and trunk appeared closer to the axis than segmental nevus depigmentosus (P < 0.001). Segmental nevus depigmentosus and segmental vitiligo showed significantly different margins (90.5% and 41.6% serrated, respectively; P < 0.001). We observed clinical differences between patients with segmental nevus depigmentosus and those with segmental vitiligo. Distribution (site, distance to axis, dermatome), vertical width, margin of lesion and presence of poliosis can be helpful in differentiating segmental nevus depigmentosus and segmental vitiligo.

Clinical Application of Cultured Stratified Epithelial Sheets Grown Under Feeder or Feeder-Free Conditions for Stable Vitiligo

BACKGROUND

Autologous cultured therapy has emerged as an effective treatment for stable vitiligo. However, culture methods may include harmful agents and be unsuitable for therapeutic use in humans.

OBJECTIVE

To investigate the safety and efficacy of autologous cultured epithelial sheets propagated under serum-free and feeder-free conditions for the treatment of stable vitiligo.

METHODS

Twenty-eight patients with stable vitiligo were included in this study. Keratinocytes and melanocytes from 14 patients were cultured under serum-free, feeder-free conditions (Group A). Epithelial cells from the remaining 14 patients were cultured according to Rheinward and Green's technique (Group B). Patients were followed up at 1, 3, 6, and 12 months after transplantation.

RESULTS

The epithelial sheets cultured in Group A were thinner and more fragile than Group B, but there were no significant differences in repigmentation between the 2 groups. At 12-month follow-up, in Group A, repigmentation at graft sites was classified as excellent in 9 patients and good in 2 patients. In Group B, repigmentation was excellent in 8 patients and good in 4 patients. Scars at the donor sites were the most frequent adverse events associated with the procedure.

CONCLUSION

Autologous epithelial sheet cultured in serum-free, feeder-free conditions is a safe and efficacious approach to cure stable vitiligo.

Skin healing and collagen changes of rats after fractional erbium:yttrium aluminum garnet laser: observation by reflectance confocal microscopy with confirmed histological evidence

The fractional erbium:yttrium aluminum garnet (Er:YAG) laser is widely applied. Microstructural changes after laser treatment have been observed with histopathology. Epidermal and dermal microstructures have also been analyzed using reflectance confocal microscopy (RCM). However, no studies have compared these two types of microstructural changes in the same subject at multiple time points after irradiation, and it is unclear if these two types of changes are consistent. We use RCM to observe the effect of different laser energies on skin healing and collagen changes in the skin of Sprague-Dawley rats that had been irradiated by fractional Er:YAG lasering at different energies. RCM was used to observe skin healing and detect collagen changes at different time points. Collagen changes were observed using hematoxylin and eosin (H&E) staining and quantitatively analyzed by western blot. RCM showed that, irrespective of laser energy, microscopic treatment zones (MTZs) were larger at 1 day after irradiation. The MTZs then reduced in size from 3 to 7 days after irradiation. The higher the energy, the larger the MTZ area. The amount of collagen also increased with time from 1 day to 8 weeks. However, the increase in the collagen amount on both RCM and H&E staining was not influenced by the laser energy. Western blotting confirmed that the amount of type I and type III collagens increased over time, but there were no significant differences between the different energy groups (p > 0.05). In conclusion, RCM is a reliable technique for observing and evaluating skin healing and collagen expression after laser irradiation.

[Leucoderma in children: Review of the literature]

BACKGROUND

Leucoderma is a frequent presenting complaint in children and it is sometimes difficult to make a definite diagnostic during the first consultation. The aim of this study is to analyse the diagnoses associated with leucoderma in children in order to propose a practical approach to their differential diagnosis.

MATERIAL AND METHODS

We performed a review of the literature using the keywords "leucoderma children review", "leucoderma Ito" and "nevus depigmentosus" in the Medline database. All relevant articles were included.

RESULTS

Four hundred and thirty-five articles were retrieved and 179 were analysed. A clinical approach was proposed in 6 articles and investigations in 15 articles.

DISCUSSION

Causal diagnosis of leucoderma may frequently be made on clinical grounds by determining the age of onset and distribution of lesions. Nevertheless, some situations require investigation. The literature is limited regarding clinical approaches and examinations in leucoderma. Herein, we present a systematic clinical and laboratory approach to the differential diagnosis of these skin disorders.