Near-ultraviolet Light Dermoscopy for Identification of Pigmented Skin Tumours

Application of Ultraviolet-Induced Fluorescence Trichoscopy (UVFT) in Hair and Scalp Diseases

INTRODUCTION

Ultraviolet-induced fluorescence dermoscopy (UVFD) is increasingly utilized in dermatooncology and general dermatology. The objective of the study was to characterize the ultraviolet-induced fluorescence trichoscopy (UVFT) findings in a wide range of hair and scalp conditions.

METHODS

Consecutive patients with non-scarring alopecias (alopecia areata, AA, n = 40; androgenetic alopecia, AGA, n = 40), scarring alopecias (frontal fibrosing alopecia, FFA, n = 20; lichen planopilaris, LPP, n = 20; folliculitis decalvans, FD, n = 14; discoid lupus erythematosus, DLE, n = 23), and inflammatory scalp conditions (psoriasis, n = 30; seborrheic dermatitis, n = 14) were included. Examinations were performed using polarized trichoscopy and UVFT.

RESULTS

The following features were observed under UVFT: white-blue perifollicular fluorescence, white-blue interfollicular fluorescence, irregular confluent dark areas, dark follicular dots, dark perifollicular areas, regular/irregular pink-red follicular fluorescence, regular/irregular green follicular fluorescence, short white hair, black dots, exclamation mark hair, double/triple white follicular dots, pink-red fluorescence of the scales, pink-red fluorescence of the background. Non-scarring alopecias showed more frequently pink-red or green follicular fluorescence (p < 0.001), dark follicular dots (p < 0.001), short white hair (p < 0.001), and double/triple white follicular dots (p < 0.001). In scarring alopecias, white-blue perifollicular fluorescence (p < 0.001), dark perifollicular areas (p < 0.001), and dark confluent areas (p < 0.001) were more commonly observed. Psoriasis showed more frequently pink-red fluorescence of the scales than seborrheic dermatitis (p = 0.019).

CONCLUSION

UVFT supports the differentiation between scarring and non-scarring alopecia, as well as between psoriasis and seborrheic dermatitis. UVFT may hypothetically facilitate the biopsy site selection by highlighting the subclinical perifollicular and interfollicular inflammation.

Ultraviolet-Induced Fluorescence Dermoscopy, a Novel Diagnostic Technique in Dermatological Practice: A Systematic Review

Introduction

Ultraviolet-induced fluorescence dermoscopy (UVF dermoscopy) is a novel diagnostic technique for identifying and diagnosing numerous skin tumors, inflammatory dermatoses, and infectious diseases. The ultraviolet (UV) band has a wavelength ranging from 10 to 400 nm. When intense UV radiation with shorter wavelengths strikes a target chromophore, visible light (VL) with a longer wavelength and lower energy is produced in the skin. This VL is apparent to the naked eye and is referred to as fluorescence.

Aim

The current review compares ultraviolet fluorescence dermoscopy (UVFD) and polarized dermoscopy (PD) features in various dermatological disorders.

Materials and Methods

This review was performed in accordance with PRISMA (Preferred Reporting Items for Systematic Reviews and Metanalyses) guidelines. A comprehensive search of the literature was carried out through the PubMed and Google Scholar electronic databases from inception to 25th December 2023 using the following search terms: "UV dermoscopy" OR "ultraviolet fluorescence dermoscopy" OR "ultraviolet-induced fluorescence dermoscopy" OR "Ultraviolet-induced fluorescent dermoscopy". Titles, abstracts, and full texts were screened by two independent reviewers to select papers dealing with UVF-dermoscopy.

Results

A total of 23 relevant articles were included in this systematic review, including a total of 313 patients. Pigmented skin tumors included 209 patients, Fordyce spot mimickers (13), scabies (57), biopsy site (20), psoriasis (3), corynebacterium infections (2), fungal infections (4), vitiligo (3), acne folliculitis (1) and glomus tumors (1). Levels of evidence (LoE) was 3 and 4 in only two included studies; the rest had a LoE of 5.

Discussion

UVF dermoscopy is a new diagnostic and prognostic tool for neoplastic and non-neoplastic dermatological conditions. This is the first systematic review of its sort that compares and categorizes dermoscopic findings in UVF and polarized light in dermatological practice. As UVFD does not penetrate deeper skin layers, we observed that it is a better way to distinguish features restricted to the skin's superficial layers in neoplastic diseases. As a result, tumor-free margins and improved surgical outcomes can be achieved. More favorable outcomes for evaluation and treatment were seen with non-neoplastic conditions. Limitations included a lack of studies with a high level of evidence, control groups, and larger sample sizes.

Conclusion

We concluded that UVFD will improve clinical diagnosis, disease management, and outcomes. More clinical trials with larger sample sizes are recommended to better understand this novel and intriguing new diagnostic tool.

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.