The dermoscopic images shown in Figure 1A and B and Figure 2 are from lesions of different skin conditions, but they all have a peculiar dermoscopic finding in common: a perifollicular white halo (PWH). The PWH is a well-demarcated, round, homogeneous whitish area, flat or prominent, measuring 0.5 to 1.5 mm in diameter, that surrounds the opening of the hair follicle (the “full-moon” sign). Figure 1 shows the dermoscopic (A and B) and histopathologic (C and D [stained with S-100 protein]) features of PWHs of melanocytic nevi, revealing a diminution of melanocytes and pigment in the skin adjacent to the hair follicle. The black on the stratum corneum seen in Figure 1C and D is India ink that has been placed on the gross specimens over the PWHs (arrows). Figure 2 shows the dermoscopic pattern of PWHs on the forehead of a child after sun exposure and tanning (A) as well as 2 processes related to dermal sun damage: actinic purpura of Bateman (B) and erythrosis interfollicularis colli of Leder (C and D), which are surrounded by structureless purpuric areas and linear vascular structures, respectively.
Vazquez-Lopez F, Mas-Vidal A, Sanchez-Martin J, Pérez-Oliva N, Argenziano G. Perifollicular White HaloA Dermoscopic Subpattern of Melanocytic and Nonmelanocytic Skin Lesions. Arch Dermatol. 2009;145(11):1350. doi:10.1001/archdermatol.2009.257