The spectrum of mild-to-severe psoriasis vulgaris is defined by a common activation of IL-17 pathway genes, but with key differences in immune regulatory genes

Mild vs. severe psoriasis vulgaris is often distinguished by the Psoriasis Area and Severity Index. It is widely assumed that severe psoriasis involves higher levels of skin inflammation, but comparative molecular profiles of mild vs. severe disease have not been previously performed. In this study, we used gene arrays to phenotype North American patients with mild psoriasis vs. severe psoriasis. 14 mild plaque psoriasis lesional skin biopsy tissues, 13 severe plaque psoriasis lesional skin biopsy tissues, and 6 normal skin tissues