Editing Psoriasis (section)

===HIV===
The rate of psoriasis in [[human immunodeficiency virus]]-positive (HIV) individuals is comparable to that of HIV-negative individuals, but psoriasis tends to be more severe in people infected with HIV.<ref name="Cedeno2011"/> A much higher rate of psoriatic arthritis occurs in HIV-positive individuals with psoriasis than in those without the infection.<ref name="Cedeno2011"/> The immune response in those infected with HIV is typically characterized by [[cytokine|cellular signals]] from [[T helper cell|T<sub>h</sub>2 subset of CD4+ helper T cells]],<ref name="Fife2007">{{cite journal | vauthors = Fife DJ, Waller JM, Jeffes EW, Koo JY | title = Unraveling the paradoxes of HIV-associated psoriasis: a review of T-cell subsets and cytokine profiles | journal = Dermatology Online Journal | volume = 13 | issue = 2 | pages = 4 | date = May 2007 | doi = 10.5070/D34SF63339 | pmid = 17498423 | url = http://dermatology.cdlib.org/132/reviews/HIV/fife.html | url-status = live | archive-url = https://web.archive.org/web/20080421173119/http://dermatology.cdlib.org/132/reviews/HIV/fife.html | archive-date = 21 April 2008 }}</ref> whereas the immune response in psoriasis vulgaris is characterized by a pattern of cellular signals typical of [[Th1 cell|T<sub>h</sub>1 subset of CD4+ helper T cells]] and [[T helper 17 cell|T<sub>h</sub>17 helper T cells]].<ref name="Wong2013">{{cite journal | vauthors = Wong T, Hsu L, Liao W | title = Phototherapy in psoriasis: a review of mechanisms of action | journal = [[Journal of Cutaneous Medicine and Surgery]] | volume = 17 | issue = 1 | pages = 6–12 | date = January–February 2013 | pmid = 23364144 | pmc = 3736829 | doi = 10.2310/7750.2012.11124 }}</ref><ref name="Martin2013">{{cite journal | vauthors = Martin DA, Towne JE, Kricorian G, Klekotka P, Gudjonsson JE, Krueger JG, Russell CB | title = The emerging role of IL-17 in the pathogenesis of psoriasis: preclinical and clinical findings | journal = The Journal of Investigative Dermatology | volume = 133 | issue = 1 | pages = 17–26 | date = January 2013 | pmid = 22673731 | pmc = 3568997 | doi = 10.1038/jid.2012.194 }}</ref> The diminished CD4+-T cell presence is thought to cause overactivation of CD8+-T cells, which are responsible for the exacerbation of psoriasis in HIV-positive people. Psoriasis in those with HIV/AIDS is often severe and may be untreatable with conventional therapy.<ref name=Rice>{{cite web |title=Images of Memorable Cases: Case 34 |quote=This AIDS patient presented with a pruritic eruption over most of his body |work=Connexions |publisher=Rice University |url=http://cnx.org/content/m14956/latest/ |access-date=21 December 2009 |archive-date=10 July 2012 |archive-url=https://archive.today/20120710172141/http://cnx.org/content/m14956/latest/ |url-status=live }}</ref> In those with long-term, well-controlled psoriasis, new HIV infection can trigger a severe flare-up of psoriasis and/or psoriatic arthritis.{{Medical citation needed|date=October 2019}}