Characterizing UV-induced fluorescence dermatoscopy (UVFD) of warts and molluscum contagiosum and its utility for expert and novice dermatoscopists

Abstract Background: Dermatoscopy is a non-invasive technique that allows visualization of skin structures not visible to the naked eye. Ultraviolet-induced fluorescence dermatoscopy (UVFD), an emerging dermatoscopy mode, has proven utility in guiding the diagnosis of skin conditions by identifying unique patterns. Objectives: The primary aim was to describe the dermatoscopic findings of warts and molluscum contagiosum (MC) using UVFD. The secondary objective was to determine the perceived diagnostic confidence of this technique across different levels of experience. Methods: We conducted a descriptive and observational study at a Tertiary Care Center. Thirty warts and fifty-five MCs were included. UVFD structures were evaluated. Diagnostic confidence (scored from 1 to 6) under UVFD was assessed for both conditions and tested across different levels of dermatoscopy expertise using an online-survey. Results: Under UVFD, 96.7% of the warts had bluish-white fluorescence (κ=0.651, substantial agreement), while 43.6% of MC were hyporeflective (κ=0.515, moderate agreement) and 100% had yellowish or bluish fluorescent rounded/oval structures (κ=1.0, almost perfect agreement). There was a statistically significant increase in the mean diagnostic confidence score when using UVFD compared to polarized light for the assessment of warts (5.52±0.45 vs. 4.89±0.75; p=0.005) and MC (5.41±0.43 vs. 5.05±0.42; p=0.012) in the ‘non-expert group’. In the ‘expert group’ this difference in confidence was not significant. Conclusions: This study highlights the potential of UVFD as a complementary tool to traditional dermatoscopy for the identification of warts and MC. UVFD might be especially relevant among less experienced dermatoscopists.