Pink-Red Fluorescence Observed in Ultraviolet-Induced Fluorescence Dermoscopy of Psoriatic Plaques

State-of-the-Art in Skin Fluorescent Photography for Cosmetic and Skincare Research: From Molecular Spectra to AI Image Analysis

Autofluorescence is a remarkable property of human skin. It can be excited by UV and observed in the dark using special detection systems. The method of fluorescence photography (FP) is an effective non-invasive tool for skin assessment. It involves image capturing by a camera the emission of light quanta from fluorophore molecules in the skin. It serves as a useful tool for cosmetic and skincare research, especially for the detection of pathological skin states, like acne, psoriasis, etc. To the best of our knowledge, there is currently no comprehensive review that fully describes the application and physical principles of FP over the past five years. The current review covers various aspects of the skin FP method from its biophysical basis and the main fluorescent molecules of the skin to its potential applications and the principles of FP recording and analysis. We pay particular attention to recently reported works on the automatic analysis of FP based on artificial intelligence (AI). Thus, we argue that FP is a rapidly evolving technology with a wide range of potential applications. We propose potential directions of the development of this method, including new AI algorithms for the analysis and expanding the range of applications.

Application of Ultraviolet-Enhanced Fluorescence Dermoscopy in Basal Cell Carcinoma

INTRODUCTION

Basal cell carcinoma (BCC) is the most common non-melanoma skin cancer. The aim of the current study was to analyze the ultraviolet-enhanced fluorescence dermoscopy (UVFD) characteristics of BCCs.

METHODS

BCCs were evaluated under polarized dermoscopy (PD) and UVFD. The findings in PD were described using predefined parameters for dermoscopic evaluation in dermato-oncology. UVFD characteristics were determined based on personal observations, and included interrupted follicle pattern, absence of pink-orange or blue-green fluorescence, well-demarcated borders, and dark silhouettes.

RESULTS

In total, 163 BCCs were analyzed. Under UVFD, the interrupted follicle pattern (p < 0.001), absence of pink-orange fluorescence (p = 0.005) and well-demarcated borders (p = 0.031) were more frequently noted in BCCs < 5 mm than in bigger tumors. Lesions on the face showed clearly defined borders (p = 0.031) and interrupted follicle pattern (p < 0.001) more frequently than tumors located beyond the face. Nodular BCCs displayed interrupted follicle pattern (p = 0.001) and absence of pink-orange fluorescence (p < 0.001) more commonly than superficial subtypes. Non-pigmented BCCs more frequently showed lack of blue-green fluorescence (p = 0.007) and interrupted follicle pattern (p = 0.018) compared to pigmented variants.

CONCLUSIONS

UVFD may be a valuable, complementary to PD, tool in the diagnosis of BCC, particularly in small tumors, lesions located on the face and nodular or non-pigmented subtypes.

Applications of Ultraviolet and Sub-ultraviolet Dermatoscopy in Neoplastic and Non-neoplastic Dermatoses: A Systematic Review

Dermatoscopy is a non-invasive and cost-efficient imaging technique augmenting clinical examination in neoplastic and non-neoplastic dermatoses. Recently, novel dermatoscopic techniques based on principles of reflectance/absorption and excited fluorescence have been developed. However, comprehensive data on their applications are sparse, and terminology is inconsistent. In this systematic review, we addressed the principles of ultraviolet (UV) imaging and proposed categorization based on spectral characteristics and signal acquisition, as well as discussed documented and potential clinical applications, safety measures during examination, and limitations associated with reflectance and fluorescence dermatoscopy. A literature search was conducted in the PubMed medical database until 2 December 2023 according to PRISMA guidelines, and 28 papers fit the scope of this review, whereas additional relevant articles were included to provide broader context regarding the chosen terminology, chromophores described, safety of sub-UV/UV, and regulations for light-emitting devices. UV and sub-UV dermatoscopy, categorized into different methods on the basis of the emitted wavelength and signal acquisition process (reflectance versus fluorescence), augment conventional dermatoscopy by optimizing safety margins in melanoma, facilitating early detection of tumor recurrence, and enhancing visualization in non-neoplastic conditions, including pigmentation disorders, intertrigo, papulo-desquamative dermatoses, and beyond. The review highlights the limitations of these techniques, including difficulty in differentiating melanin from hemoglobin, challenges in evaluating uneven surfaces, and artifacts. Although UV dermatoscopy complements conventional dermatoscopy, clinicians should be aware of their peculiarities, artifacts, limitations, and safety concerns to optimize their diagnostic accuracy and ensure patient's safety.

Porokeratoses-A Comprehensive Review on the Genetics and Metabolomics, Imaging Methods and Management of Common Clinical Variants

Porokeratosis is a heterogeneous group of keratinising disorders characterised by the presence of particular microscopic structural changes, namely the presence of the cornoid lamella. This structure develops as a consequence of a defective isoprenoid pathway, critical for cholesterol synthesis. Commonly recognised variants include disseminated superficial actinic porokeratosis, disseminated superficial porokeratosis, porokeratosis of Mibelli, palmoplantar porokeratosis (including porokeratosis palmaris et plantaris disseminata and punctate porokeratosis), linear porokeratosis, verrucous porokeratosis (also known as genitogluteal porokeratosis), follicular porokeratosis and porokeratoma. Apart from the clinical presentation and epidemiology of each variant listed, this review aims at providing up-to-date information on the precise genetic background, introduces imaging methods facilitating the diagnosis (conventional and ultraviolet-induced fluorescence dermatoscopy, reflectance confocal microscopy and pathology), discusses their oncogenic potential and reviews the literature data on the efficacy of the treatment used, including the drugs directly targeting the isoprenoid-mevalonate pathway.