Editing Lichen simplex chronicus (section)

== Causes ==
This is a skin disorder characterized by a self-perpetuating scratch-itch cycle:<ref>{{Cite journal|last1=Lee|first1=Michael R.|last2=Shumack|first2=Stephen|date=2005-11-01|title=Prurigo nodularis: a review|journal=The Australasian Journal of Dermatology|volume=46|issue=4|pages=211–218; quiz 219–220|doi=10.1111/j.1440-0960.2005.00187.x|issn=0004-8380|pmid=16197418|s2cid=30087432}}</ref> 
*It may begin with something that rubs, irritates, or scratches the skin, such as clothing.
*This causes the person to rub or scratch the affected area. Constant scratching causes the skin to thicken.
*The thickened skin itches, causing more scratching, causing more thickening.
*Affected area may spread rapidly through the rest of the body.
Many hypothesize LSC has a psychosomatic origin.<ref name=":1">{{Cite journal|last1=Lotti|first1=Torello|last2=Buggiani|first2=Gionata|last3=Prignano|first3=Francesca|date=2008-01-01|title=Prurigo nodularis and lichen simplex chronicus|journal=Dermatologic Therapy|language=en|volume=21|issue=1|pages=42–46|doi=10.1111/j.1529-8019.2008.00168.x|pmid=18318884|s2cid=41222102|issn=1529-8019}}</ref> Those predisposed to itch as a response to emotional tensions may be more susceptible to the itch-scratch cycle. It may also be associated with nervousness, [[anxiety]], [[clinical depression|depression]], and other psychological disorders.<ref>{{Cite journal|last1=Konuk|first1=Numan|last2=Koca|first2=Rafet|last3=Atik|first3=Levent|last4=Muhtar|first4=Sennur|last5=Atasoy|first5=Nuray|last6=Bostanci|first6=Bora|date=2007-05-01|title=Psychopathology, depression and dissociative experiences in patients with lichen simplex chronicus|url=http://www.ghpjournal.com/article/S0163-8343(07)00007-2/abstract|journal=General Hospital Psychiatry|language=en|volume=29|issue=3|pages=232–235|doi=10.1016/j.genhosppsych.2007.01.006|pmid=17484940|issn=0163-8343|url-access=subscription}}</ref><ref>{{Cite journal|last1=Krishnan|first1=Anjeli|last2=Koo|first2=John|date=2005-07-01|title=Psyche, opioids, and itch: therapeutic consequences|journal=Dermatologic Therapy|volume=18|issue=4|pages=314–322|doi=10.1111/j.1529-8019.2005.00038.x|issn=1396-0296|pmid=16297003|s2cid=25983822|doi-access=free}}</ref> Many people with LSC are aware of the scratching they do during the day, but they might not be aware of the scratching they do in their sleep.<ref name=":0" /> LSC is also associated with [[atopy]], or [[atopic dermatitis]] (eczema) and an increase of histamine levels.<ref name=":0" />