Dermoscopy of acquired pigmentary disorders: a comprehensive review

Dermoscopy has traditionally been used for the diagnosis of neoplasms and more recently in the evaluation of inflammatory conditions. Recent observational studies have suggested a role for dermoscopy in identifying and differentiating acquired pigmentary disorders. This comprehensive review will summarize the growing literature on the use of dermoscopy for pigmentary disorders. A literature review was performed on PubMed dating from inception to October 2020. The following pigmentary disorders were included in this study: melasma, solar lentigines, poikiloderma of Civatte, exogenous ochronosis, lichen planus pigmentosus, erythromelanosis follicularis faciei et colli, pigmented contact dermatitis, Riehl's melanosis, postinflammatory hyperpigmentation, erythema dyschromicum perstans, ashy dermatosis, confluent and reticulated papillomatosis, acanthosis nigricans, pityriasis versicolor, tinea versicolor, idiopathic guttate hypomelanosis, and vitiligo. Search terms used included each pigmentary disorder along with the terms "dermoscopy" or "dermatoscopy." Relevant case reports and case series were included. Many pigmentary disorders have unique and distinguishable features on dermoscopy. Given that these disorders can be clinically challenging for clinicians and emotionally distressing for patients, dermoscopy provides an additional, useful tool in the evaluation and assessment process.