Dermoscopy of Porokeratosis of Mibelli

© 2017 Indian Dermatology Online Journal | Published by Wolters Kluwer Medknow A 24‐year‐old man presented with a single asymptomatic reddish‐brown annular plaque of 8‐months duration over the outer right arm [Figure 1]. Dermoscopy revealed a central homogenous skin‐colored to pale area with brown‐colored dots, globules, and an irregular double‐marginated track‐like border, most prominent around the 2 o’clock and 8 o’clock position. In some sections of this track, brown dots/globules coalesced to form a continuous brown‐colored line within the whitish rim [Figure 2]. Histopathology confirmed the diagnosis of porokeratosis [Figure 3]. A final diagnosis of porokeratosis of Mibelli was made. Dermoscopy of porokeratosis (PK) typically reveals central white area of scarring, red‐brown dots and globules, and vessels of different patterns. The dermoscopically diagnostic finding is the white peripheral border, often double‐marginated, representing coronoid lamella.[1] It has been metaphorically called “white track” or “lines of volcanic crater,” and “diamond necklace” on ultraviolet light dermoscopy. Minor differences have been reported in the