Inflammatory and infectious conditions

The presence of Wickham striae (WS) is the dermoscopic hallmark of lichen planus (LP) across all skin types.1–6 Many patterns of WS have been described in lighter skin types, including reticular (the most common one), circular, radial streaming, linear, globular, veil-like, leaf venation-like, and/or “starry sky”/white dots.1–6 Although reticular arrangement (Figures 18.1 and 18.2) and “starry sky” appearance are the most frequent patterns, it is not uncommon to come across lesions featuring peripheral radial streaming (chrysalis-like) (Figure 18.3) or stacked-linear structures (Figure 18.4) in dark-skinned patients (authors’ personal observations). Importantly, WS may display different color shades, including white, yellow, and bluish, with the last one being much more common compared to fair-skinned patients (Figures 18.2 and 18.3).1–6 Figure 18.1 Dermoscopy of LP (active lesion): pinkish-erythematous background with white WS having a reticular arrangement. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315201733/06ba575d-99fb-477c-8154-4e79dfc8418b/content/fig18_1.jpg"/> Figure 18.2 Dermoscopy of LP (active lesion) in a very dark phototype: bluish WS displaying a reticular/arborizing appearance. (Courtesy of Enzo Errichetti, MD, MSc, DVD, Udine Italy.) https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315201733/06ba575d-99fb-477c-8154-4e79dfc8418b/content/fig18_2.jpg"/> Figure 18.3 Dermoscopy of LP (active lesion): reddish-brown background with radially arranged bluish-white linear streaks of WS along with brownish/blue-gray dots/globules and clods. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315201733/06ba575d-99fb-477c-8154-4e79dfc8418b/content/fig18_3.jpg"/> Figure 18.4 <target id="page_271" target-type="page">271</target>Dermoscopy of LP (active lesion): WS arra­nged in a stacked-linear pattern over a reddish-brown background. https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9781315201733/06ba575d-99fb-477c-8154-4e79dfc8418b/content/fig18_4.jpg"/>