Editing Psoriasis (section)

====Pathogenetic====
Another classification scheme considers genetic and demographic factors. Type 1 has a positive family history, starts before the age of 40, and is associated with the [[human leukocyte antigen]], [[HLA-C|''HLA-Cw6'']]. Conversely, type 2 does not show a family history, presents after age 40, and is not associated with ''HLA-Cw6''.<ref name=Kupetsky2013 /> Type 1 accounts for about 75% of persons with psoriasis.<ref>{{cite journal | vauthors = Griffiths CE, Christophers E, Barker JN, Chalmers RJ, Chimenti S, Krueger GG, Leonardi C, Menter A, Ortonne JP, Fry L | title = A classification of psoriasis vulgaris according to phenotype | journal = The British Journal of Dermatology | volume = 156 | issue = 2 | pages = 258–62 | date = February 2007 | pmid = 17223864 | doi = 10.1111/j.1365-2133.2006.07675.x | s2cid = 45917573 }}</ref>

The classification of psoriasis as an autoimmune disease has sparked considerable debate. Researchers have proposed differing descriptions of psoriasis and psoriatic arthritis; some authors have classified them as autoimmune diseases<ref name="Raychaudhuri2014"/><ref name="Prieto2013"/><ref name="Weidemann2013">{{cite journal | vauthors = Weidemann AK, Crawshaw AA, Byrne E, Young HS | title = Vascular endothelial growth factor inhibitors: investigational therapies for the treatment of psoriasis | journal = Clinical, Cosmetic and Investigational Dermatology | volume = 6 | pages = 233–44 | date = September 2013 | pmid = 24101875 | pmc = 3790838 | doi = 10.2147/CCID.S35312 | doi-access = free }}</ref> while others have classified them as distinct from autoimmune diseases and referred to them as [[immune-mediated inflammatory diseases]].<ref name=Nestle/><ref name="Han2012">{{cite journal | vauthors = Han R, Rostami-Yazdi M, Gerdes S, Mrowietz U | title = Triptolide in the treatment of psoriasis and other immune-mediated inflammatory diseases | journal = British Journal of Clinical Pharmacology | volume = 74 | issue = 3 | pages = 424–36 | date = September 2012 | pmid = 22348323 | pmc = 3477344 | doi = 10.1111/j.1365-2125.2012.04221.x }}</ref><ref name="Quatresooz">{{cite journal | vauthors = Quatresooz P, Hermanns-Lê T, Piérard GE, Humbert P, Delvenne P, Piérard-Franchimont C | title = Ustekinumab in psoriasis immunopathology with emphasis on the Th17-IL23 axis: a primer | journal = Journal of Biomedicine & Biotechnology | volume = 2012 | issue = 147413 | pages = 147413 | date = June 2012 | pmid = 22754278 | pmc = 3384985 | doi = 10.1155/2012/147413 | doi-access = free | title-link = doi }}</ref>