UpToDate Dermatology 2020

Dermoscopy is a noninvasive, in vivo technique primarily used for the examination of pigmented skin lesions; however, it can also assist observers in assessing lesions with little to no pigment [1]. Dermatoscopy, epiluminescence microscopy, incident light microscopy, and skin-surface microscopy are synonyms. Dermoscopy is performed with a handheld instrument called a dermatoscope. The procedure allows for the visualization of subsurface skin structures in the epidermis, at the dermoepidermal junction, and in the upper dermis; these structures are usually not visible to the naked eye [2-4]. The dermoscopic images may be photographed or recorded digitally for storage or sequential analysis. The basic principles of dermoscopy will be discussed in this topic. The dermoscopic diagnosis of skin lesions, including those in special anatomic areas (eg, face, volar surfaces of palms and soles, mucosal surfaces, and glabrous skin in genital area), dermoscopy of nail pigmentation, and algorithms used for skin cancer triage are discussed separately.