ABSTRACT
The value of dermatoscopy in the diagnosis of pigmented and nonpigmented skin neoplasms has been well documented. Along with patients' history and clinical examination, the dermatoscopic evaluation of structures and features invisible to the naked eye facilitates discrimination among different inflammatory and infectious diseases. Scale color is crucial for the differentiation of psoriasis from other erythematous scaly dermatoses. Scalp psoriasis displays additional features including ring vessels, red loops, punctate hemorrhages, and perifollicular plugs, while palmoplantar pustulosis displays the typical yellow and brown pustules. The dermatoscopic hallmark of dermatitis consists of dotted vessels in a patchy distribution and yellow scales/serocrusts, histologically corresponding to dermal spongiosis. The vessels’ morphology is similar in psoriasis and dermatitis. The dermatoscopic hallmark of lichen planus is Wickham striae (WS). WS consists of linear reticulated, or annular, white structures that may develop starburst projections. The most common dermatoscopic feature of pityriasis rosea is the whitish fine scales at the periphery of the patches.
