**2.1 Plaque psoriasis**

Plaque psoriasis is the most common clinical subtype of psoriasis with 90% of all cases [4]. It is characterized by erythematous, well-defined, and usually indurated plaques greater than 1 cm in size with white-silvery scales on them (**Figure 1**). They can vary in size and may coalesce. Especially rapidly progressing lesions can be seen in annular configuration (**Figure 2**) [4, 5]. Removal of psoriatic scales may cause pinpoint bleedings, which is called Auspitz sign. Psoriatic plaques are mostly located in the scalp, trunk, lumbosacral area, and extensor surfaces of extremities (**Figure 3**) [6].
