*2.1.1 Dermoscopy of plaque psoriasis*

Dermoscopic examination of a psoriasis plaque should be done in three categories: background, vessels, and scales. Examination should be done with minimal pressure to visualize vessels better and with immersion oil if possible.

In dermoscopic examination of plaque psoriasis with handheld dermoscope, we usually see regularly distributed dotted vessels in a reddish-pinkish background and white scales (**Figure 4**) [7]. In some cases, background can be grayish-white due to highly hyperkeratotic scales (**Figure 5**).

Apart from regular distribution, vessels can be distributed scattered, in clusters, in rings, and patchy (**Figure 6a**). In higher magnifications (with videodermoscopy), these dotted vessels can be seen as bushy capillaries, globules, radial capillaries, globular rings, hairpin capillaries, and comma vessels in descending order [8] (**Figure 6b**). Rarely dot blood hemorrhages can be seen in vessel locations (**Figure 5**). Scales can be distributed diffuse, patchy, central, or peripheral in descending order; however, white color is key point for scales [8, 9].

**Figure 1.** *Erythematous, well-defined indurated plaque with white scales.*

*Dermoscopic Differential Diagnosis of Psoriasis DOI: http://dx.doi.org/10.5772/intechopen.103004*

**Figure 2.** *Erythematous, annular plaques with white scales.*

**Figure 3.** *Psoriatic plaques located on the trunk and extensor surfaces of the arms.*
