Ultraviolet imaging in dermatology

Visual examination plays a central role in the diagnosis of skin diseases. Many dermatologists use magnification, or dermoscopy, to improve diagnostic certainty when assessing the skin under visible light. In addition to magnification, other technological advances have been made over the last century to improve our visual assessment of the skin. Examination of skin under ultraviolet (UV) radiation, with Wood's light, gained traction for its utility in assessing superficial cutaneous infections and pigmentary changes. During Wood's light examination, UV light is directed at the skin and fluorescence is detected by our eyes. The variable fluorescent characteristics of endogenous and exogenous cutaneous chromophores help us better diagnose skin disease. UV fluorescent photography is based on the same concept as the Wood's light, but also allows image analysis and documentation of the captured image. In addition to UV-induced fluorescence, the differential reflection and absorption of UV light captured in the UV spectral range can also provide a new contrast for diagnosing skin diseases during UV reflectance photography. This review discusses the most widely used UV imaging techniques and provides an overview of the role of UV imaging in dermatology.