RESUMO
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.
RESUMO
BACKGROUND: Preliminary data support the possible use of ultraviolet-induced fluorescence (UVF) dermoscopy in general dermatology, yet no accuracy analysis has been performed so far. OBJECTIVE: To evaluate diagnostic accuracy of UVF dermoscopy in clinically similar non-neoplastic conditions as compared to polarized light-based dermoscopy. METHODS: Patients with dermatoses potentially showing UV-induced findings were considered; cases were grouped according to clinical patterns and controls were also included. Standardized evaluation of dermoscopic pictures of the target lesion along with comparative and accuracy analysis were performed for polarized and UVF dermoscopic findings. RESULTS: A total of 208 patients were included [31 foot intertrigo (7 due to Pseudomonas, 13 due to Corynebacterium and 11 due to dermatophytes); 57 intertrigo of major creases (18 inverse psoriasis, 13 erythrasma, 15 tinea infections and 11 candidiasis); 16 acne (papulopustular) and 13 Malassezia folliculitis; 46 papulosquamous dermatoses (14 guttate psoriasis, 11 lichen planus, 12 pityriasis rosea and 9 pityriasis lichenoide chronica); and 45 hypopigmented macular dermatoses of the trunk (9 progressive macular hypomelanosis, 9 idiopatic guttate hypomelanosis, 13 vitiligo and 14 achromic pityriasis versicolor)]. Significant (p < 0.01) UVF was seen in several conditions: green in Pseudomonas foot intertrigo; red in Corynebacterium foot intertrigo, inverse and guttate psoriasis (arranged around dermal papillae in the former), progressive macular hypomelanosis (folliculocentric distribution) and erythrasma (showing polygonal or structureless appearance); blue fluorescent concretions along hair shaft in erythrasma; light green in achromic pityriasis versicolor and tinea of major creases; and blue follicular in Malassezia folliculitis. Additionally, both acne and achromic pityriasis versicolor were also associated with interruption of uniform follicular red fluorescence. Notably, polarized and UVF dermoscopy were related to the most accurate feature in nine and eight analysed dermatoses, respectively. CONCLUSION: UVF dermoscopy improves recognition of non-neoplastic dermatoses, yet it should be considered complimentary to polarized light-based dermoscopy to increase diagnostic performance.