Editing Psoriasis (section)

==Signs and symptoms==

===Plaque psoriasis===
[[File:Psoriasis2010.JPG|thumbnail|Psoriatic plaque, showing a silvery center surrounded by a reddened border]]
Psoriasis vulgaris (also known as chronic stationary psoriasis or plaque-like psoriasis) is the most common form and affects 85–90% of people with psoriasis.<ref name="Palfreeman2013"/> Plaque psoriasis typically appears as raised areas of [[Inflammation|inflamed]] skin covered with silvery-white, scaly skin. These areas are called plaques and are most commonly found on the elbows, knees, [[scalp]], and back.<ref name="Palfreeman2013"/><ref name=DAVIDSONS2010>{{cite book| veditors = Colledge NR, Walker BR, Ralston SH |title=Davidson's principles and practice of medicine.|year=2010|publisher=Churchill Livingstone/Elsevier|location=Edinburgh|isbn=978-0-7020-3084-0|edition=21st | pages=1260–1 }}</ref>

<gallery>
Image:Psoriasis2010a.JPG|Plaques of psoriasis
Image:Psoriasis.jpg|A person's arm covered with plaque psoriasis
File:Psoriasis of the palms.jpg|Psoriasis of the palms
Riehl Zumbusch Tafel LII (1).jpg|Psoriasis of the scalp
</gallery>

=== Other forms ===
Additional types of psoriasis comprise about 10% of cases. They include pustular, inverse, napkin, guttate, oral, and seborrheic-like forms.<ref name="Andrews">{{cite book | vauthors = James W, Berger T, Elston D |title=Andrews' Diseases of the Skin: Clinical Dermatology |publisher=Saunders |year=2005 |isbn=978-0-7216-2921-6 |edition=10th|pages=191–7 }}</ref>

====Pustular psoriasis====
[[File:Psoriasis manum.jpg|thumbnail|Severe generalized pustular psoriasis]]
[[Pustular psoriasis]] appears as raised bumps filled with noninfectious pus ([[pustules]]).<ref>{{cite journal | vauthors = Robinson A, Van Voorhees AS, Hsu S, Korman NJ, Lebwohl MG, Bebo BF, Kalb RE | title = Treatment of pustular psoriasis: from the Medical Board of the National Psoriasis Foundation | journal = Journal of the American Academy of Dermatology | volume = 67 | issue = 2 | pages = 279–88 | date = August 2012 | pmid = 22609220 | doi = 10.1016/j.jaad.2011.01.032 }}</ref> The skin under and surrounding the pustules is red and tender.<ref name="Raychaudhuri2014" /> Pustular psoriasis can either be localized or more widespread throughout the body. Two types of localized pustular psoriasis include psoriasis pustulosa palmoplantaris and [[Dermatitis repens|acrodermatitis continua of Hallopeau]]; both forms are localized to the hands and feet.<ref name="Rendon2019" />

==== Inverse psoriasis ====
[[Inverse psoriasis]] (also known as flexural psoriasis) appears as smooth, inflamed patches of skin. The patches frequently affect [[skin fold]]s, particularly around the [[genitals]] (between the thigh and groin), the [[armpit]]s, in the skin folds of an overweight abdomen (known as [[panniculus]]), between the buttocks in the intergluteal cleft, and under the [[breasts]] in the [[inframammary fold]]. Heat, trauma, and infection are thought to play a role in the development of this atypical form of psoriasis.<ref name="Weigle2013" />

==== Napkin psoriasis ====
[[Napkin psoriasis]] is a subtype of psoriasis common in infants under the age of two and is characterized by red papules with silver scales in the diaper area that may extend to the torso or limbs.<ref name="Gudjonsson2012" /><ref>{{Cite journal |last1=Afsar |first1=Fatma Sule |last2=Uysal |first2=Sila Seremet |last3=Salis |first3=Fatma Muderrisoglu |last4=Calli |first4=Aylin Orgen |date=May 2016 |title=Napkin psoriasis |url=https://onlinelibrary.wiley.com/doi/10.1111/ped.12916 |journal=Pediatrics International |language=en |volume=58 |issue=5 |pages=420–422 |doi=10.1111/ped.12916 |pmid=27103532 |issn=1328-8067}}</ref> Napkin psoriasis is often misdiagnosed as [[irritant diaper dermatitis|napkin dermatitis]] (diaper rash).<ref name="Gelmetti2009">{{cite journal | vauthors = Gelmetti C | title = Therapeutic moisturizers as adjuvant therapy for psoriasis patients | journal = American Journal of Clinical Dermatology | volume = 10 | issue = Suppl 1 | pages = 7–12 | date = January 2009 | pmid = 19209948 | doi = 10.2165/0128071-200910001-00002 | s2cid = 9513914 }}</ref> It typically improves as children age and may later present in more common forms as [[plaque psoriasis]] or [[inverse psoriasis]].<ref>{{Cite journal |last=Mahé |first=Emmanuel |date=November 2016 |title=Childhood psoriasis |url=http://www.john-libbey-eurotext.fr/medline.md?doi=10.1684/ejd.2016.2932 |journal=European Journal of Dermatology |volume=26 |issue=6 |pages=537–548 |doi=10.1684/ejd.2016.2932 |pmid=27900946 |issn=1167-1122}}</ref>

==== Guttate psoriasis ====
[[File:Psoriasis en gouttes enfant 2.jpg|thumbnail|Example of [[guttate psoriasis]]]]
[[Guttate psoriasis]] is an inflammatory condition characterized by numerous small, scaly, red or pink, droplet-like lesions (papules). These numerous papules appear over large areas of the body, primarily the [[Torso|trunk]], limbs, and scalp, but typically spare the palms and soles. Guttate psoriasis is often triggered by a [[Group A beta-hemolytic streptococcus|streptococcal]] infection ([[Pharynx|oropharyngeal]] or perianal) and typically occurs 1–3 weeks post-infection. [[Guttate psoriasis]] is most commonly seen in children and young adults and diagnosis is typically made based on history and clinical exam findings.<ref name=Saleh22>{{cite book |vauthors=Saleh D, Tanner LS |chapter=Guttate Psoriasis |date=August 2022 |title=((StatPearls [Internet])) |location=Treasure Island (FL) |publisher=StatPearls Publishing |pmid=29494104}}</ref> Skin [[biopsy]] can also be performed which typically shows a psoriasiform reaction pattern characterized by epidermal [[hyperplasia]] with elongation of the [[Rete pegs|rete ridges]].<ref name=Saleh22/>

There is no firm evidence regarding the best management for guttate psoriasis; however, first-line [[therapy]] for mild guttate psoriasis typically includes topical corticosteroids.<ref name=Saleh22/><ref>{{cite journal |vauthors=Chalmers RJ, O'Sullivan T, Owen CM, Griffiths CE |title=A systematic review of treatments for guttate psoriasis |journal=Br J Dermatol |date=2001 |volume=145 |issue=6 |pages=891–4 |doi= 10.1046/j.1365-2133.2001.04505.x |pmid=11899141|s2cid=27381477 |doi-access=free }}</ref> [[Light therapy|Phototherapy]] can be used for moderate or severe guttate psoriasis. Biologic treatments have not been well studied in the treatment of guttate psoriasis.<ref name=Saleh22/>

Guttate psoriasis has a better [[prognosis]] than plaque psoriasis and typically resolves within 1–3 weeks; however, up to 40% of patients with guttate psoriasis eventually convert to plaque psoriasis.<ref name=Saleh22/><ref name="Weigle2013">{{cite journal | vauthors = Weigle N, McBane S | title = Psoriasis | journal = American Family Physician | volume = 87 | issue = 9 | pages = 626–33 | date = May 2013 | pmid = 23668525 | url = http://www.aafp.org/afp/2013/0501/p626.html | archive-url = https://web.archive.org/web/20150215233455/http://www.aafp.org/afp/2013/0501/p626.html | url-status = live | archive-date = 15 February 2015 }}</ref>

==== Erythrodermic psoriasis ====
[[Psoriatic erythroderma]] (erythrodermic psoriasis) involves widespread inflammation and exfoliation of the skin over most of the body surface, often involving greater than 90% of the body surface area.<ref name="Rendon2019">{{cite journal | vauthors = Rendon A, Schäkel K | title = Psoriasis Pathogenesis and Treatment | journal = International Journal of Molecular Sciences | volume = 20 | issue = 6 | pages = 1475 | date = March 2019 | pmid = 30909615 | doi = 10.3390/ijms20061475 | pmc = 6471628 | doi-access = free | title-link = doi }}</ref> It may be accompanied by severe dryness, itching, swelling, and pain. It can develop from any type of psoriasis.<ref name="Rendon2019" /> It is often the result of an exacerbation of unstable plaque psoriasis, particularly following the abrupt withdrawal of systemic [[glucocorticoid]]s.<ref name="Zattra2012">{{cite journal | vauthors = Zattra E, Belloni Fortina A, Peserico A, Alaibac M | title = Erythroderma in the era of biological therapies | journal = European Journal of Dermatology | volume = 22 | issue = 2 | pages = 167–71 | date = May 2012 | pmid = 22321651 | doi = 10.1684/ejd.2011.1569 }}</ref> This form of psoriasis can be fatal as the extreme inflammation and exfoliation disrupt the body's ability to [[Thermoregulation|regulate temperature]] and perform barrier functions.<ref name="DermNZ">{{cite web | vauthors = Stanway A | title=Erythrodermic psoriasis | url=http://dermnetnz.org/scaly/erythrodermic-psoriasis.html | publisher=DermNet NZ | access-date=16 March 2014 | url-status=live | archive-url=https://web.archive.org/web/20140202222207/http://dermnetnz.org/scaly/erythrodermic-psoriasis.html | archive-date=2 February 2014 }}</ref>

==== Mouth ====
Psoriasis in the mouth is very rare, in contrast to [[lichen planus]], another common papulosquamous disorder that commonly involves both the skin and mouth.<ref name="Yesudian2012">{{cite journal | vauthors = Yesudian PD, Chalmers RJ, Warren RB, Griffiths CE | title = In search of oral psoriasis | journal = Archives of Dermatological Research | volume = 304 | issue = 1 | pages = 1–5 | date = January 2012 | pmid = 21927905 | doi = 10.1007/s00403-011-1175-3 | s2cid = 33434341 }}</ref> When psoriasis involves the oral [[Mucous membrane|mucosa]] (the lining of the mouth), it may be asymptomatic,<ref name="Yesudian2012"/> but it may appear as white or grey-yellow plaques.<ref name="Yesudian2012"/> [[Fissured tongue]] is the most common finding in those with oral psoriasis and has been reported to occur in 6.5–20% of people with psoriasis affecting the skin. The microscopic appearance of oral mucosa affected by [[geographic tongue]] (migratory stomatitis) is very similar to the appearance of psoriasis.<ref>{{cite book | vauthors = Greenberg MS, Glick M, Ship JA | title = Burket's oral medicine | year = 2008 | publisher = BC Decker | location = Hamilton, Ont | isbn = 978-1-55009-345-2 | pages = 103–4 | edition = 11th }}</ref> A recent study found an association between the two conditions, and it suggests that geographic tongue might be a predictor for psoriasis.<ref>{{Cite journal |last1=González-Álvarez |first1=Laura |last2=García-Martín |first2=José M. |last3=García-Pola |first3=María José |date=May 2019 |title=Association between geographic tongue and psoriasis: A systematic review and meta-analyses |url=https://pubmed.ncbi.nlm.nih.gov/30739339/ |journal=Journal of Oral Pathology & Medicine|volume=48 |issue=5 |pages=365–372 |doi=10.1111/jop.12840 |issn=1600-0714 |pmid=30739339}}</ref>

==== Seborrheic-like psoriasis ====
[[Seborrheic-like psoriasis]] is a common form of psoriasis with clinical aspects of psoriasis and [[seborrheic dermatitis]], and it may be difficult to distinguish from the latter. This form of psoriasis typically manifests as red plaques with greasy scales in areas of higher [[sebum]] production such as the [[scalp]], [[forehead]], [[nasolabial fold|skin folds next to the nose]], the skin surrounding the mouth, skin on the chest above the [[sternum]], and in [[intertriginous|skin folds]].<ref name="Gudjonsson2012"/>

===Psoriatic arthritis===
[[Psoriatic arthritis]] is a form of chronic inflammatory [[arthritis]] that has a highly variable clinical presentation and frequently occurs in association with skin and nail psoriasis.<ref name="Chimenti2013">{{cite journal | vauthors = Chimenti MS, Saraceno R, Chiricozzi A, Giunta A, Chimenti S, Perricone R | title = Profile of certolizumab and its potential in the treatment of psoriatic arthritis | journal = Drug Design, Development and Therapy | volume = 7 | pages = 339–48 | date = April 2013 | pmid = 23620660 | pmc = 3633576 | doi = 10.2147/DDDT.S31658 | doi-access = free }}</ref><ref name="Goldenstein2012"/> It typically involves painful inflammation of the joints and [[Synovitis|surrounding connective tissue]] and can occur in any joint, but most commonly affects the joints of the fingers and toes. This can result in a sausage-shaped swelling of the fingers and toes known as [[dactylitis]].<ref name="Chimenti2013"/> Psoriatic arthritis can also affect the hips, knees, spine ([[spondylitis]]), and [[sacroiliac joint]] ([[sacroiliitis]]).<ref name="Krawczyk2013">{{cite journal | vauthors = Krawczyk-Wasielewska A, Skorupska E, Samborski W | title = Sacroiliac joint pain as an important element of psoriatic arthritis diagnosis | journal = Postepy Dermatologii I Alergologii | volume = 30 | issue = 2 | pages = 108–12 | date = April 2013 | pmid = 24278057 | pmc = 3834688 | doi = 10.5114/pdia.2013.34161 }}</ref> About 30% of individuals with psoriasis will develop psoriatic arthritis.<ref name="Palfreeman2013">{{cite journal | vauthors = Palfreeman AC, McNamee KE, McCann FE | title = New developments in the management of psoriasis and psoriatic arthritis: a focus on apremilast | journal = Drug Design, Development and Therapy | volume = 7 | pages = 201–10 | date = March 2013 | pmid = 23569359 | pmc = 3615921 | doi = 10.2147/DDDT.S32713 | doi-access = free }}</ref> Skin manifestations of psoriasis tend to occur before arthritic manifestations in about 75% of cases.<ref name="Goldenstein2012">{{cite journal | vauthors = Goldenstein-Schainberg C, Favarato MH, Ranza R | title = Current and relevant concepts in psoriatic arthritis | journal = Revista Brasileira de Reumatologia | volume = 52 | issue = 1 | pages = 98–106 | date = January–February 2012 | pmid = 22286649 | doi = 10.1590/s0482-50042012000100010 | doi-access = free | title-link = doi }}</ref>

===Nail changes===
[[File:Luszczyca paznokcia.jpg|thumbnail|Psoriasis of a fingernail, with visible pitting]]
[[File:NailPsoriasis.JPG|thumb|Effect of psoriasis on the toenails]]
[[Psoriatic nails|Psoriasis can affect the nails]] and produces a variety of changes in the appearance of fingers and toenails. Nail psoriasis occurs in 40–45% of people with psoriasis affecting the skin, and has a lifetime incidence of 80–90% in those with psoriatic arthritis.<ref name="Tan2012">{{cite journal | vauthors = Tan ES, Chong WS, Tey HL | title = Nail psoriasis: a review | journal = American Journal of Clinical Dermatology | volume = 13 | issue = 6 | pages = 375–88 | date = December 2012 | pmid = 22784035 | doi = 10.2165/11597000-000000000-00000 | s2cid = 8561015 }}</ref> These changes include pitting of the nails (pinhead-sized depressions in the nail is seen in 70% with nail psoriasis), [[leukonychia|whitening of the nail]], [[splinter hemorrhage|small areas of bleeding from capillaries under the nail]], yellow-reddish discoloration of the nails known as the oil drop or salmon spots, dryness, thickening of the skin under the nail (subungual hyperkeratosis), loosening and separation of the nail ([[onycholysis]]), and crumbling of the nail.<ref name="Tan2012"/>

===Medical signs===
In addition to the appearance and distribution of the rash, specific [[medical sign]]s may be used by medical practitioners to assist with diagnosis. These may include [[Auspitz's sign]] (pinpoint bleeding when the scale is removed), [[Koebner phenomenon]] (psoriatic skin lesions induced by trauma to the skin),<ref name="Gudjonsson2012">{{cite book|vauthors=Gudjonsson JE, Elder JT, Goldsmith LA, Katz SI, Gilchrest BA, Paller AS, Leffell DJ, Wolff K |title=Fitzpatrick's Dermatology in General Medicine|year=2012|publisher=McGraw-Hill|isbn=978-0-07-166904-7|edition=8th|chapter=18: Psoriasis }}</ref> and [[Pruritus|itching]] and pain localized to papules and plaques.<ref name="Weigle2013"/><ref name="Gudjonsson2012"/>