Editing Acne (section)

===Scars===
Acne [[scar]]s are caused by [[inflammation]] within the [[dermis]] and are estimated to affect 95% of people with acne vulgaris.<ref name="Fife2016">{{cite journal | vauthors = Fife D | title = Evaluation of Acne Scars: How to Assess Them and What to Tell the Patient | journal = Dermatologic Clinics | volume = 34 | issue = 2 | pages = 207–13 | date = April 2016 | pmid = 27015781 | doi = 10.1016/j.det.2015.11.009 | type = Review }}</ref> Abnormal healing and dermal inflammation create the scar.<ref name=Levy2012>{{cite journal | vauthors = Levy LL, Zeichner JA | title = Management of acne scarring, part II: a comparative review of non-laser-based, minimally invasive approaches | journal = American Journal of Clinical Dermatology | volume = 13 | issue = 5 | pages = 331–40 | date = October 2012 | pmid = 22849351 | doi = 10.2165/11631410-000000000-00000 | s2cid = 41448330 | type = Review }}</ref> Scarring is most likely to take place with severe acne but may occur with any form of acne vulgaris.<ref name="Fife2016"/> Acne scars are classified based on whether the abnormal healing response following dermal inflammation leads to excess [[collagen]] deposition or loss at the site of the acne lesion.<ref name="Sanchez2015">{{cite journal | vauthors = Sánchez Viera M | title = Management of acne scars: fulfilling our duty of care for patients | journal = The British Journal of Dermatology | volume = 172 Suppl 1 | issue = Supplement 1 | pages = 47–51 | date = July 2015 | pmid = 25597636 | doi = 10.1111/bjd.13650 | type = Review }}</ref>

Atrophic acne scars have lost collagen from the healing response and are the most common type of acne scar (accounting for approximately 75% of all acne scars).<ref name=Levy2012/><ref name="Sanchez2015"/> Ice-pick scars, boxcar scars, and rolling scars are subtypes of atrophic acne scars.<ref name="Fife2016"/> Boxcar scars are round or ovoid indented scars with sharp borders and vary in size from 1.5–4&nbsp;mm across.<ref name=Levy2012/> Ice-pick scars are narrow (less than 2&nbsp;[[Millimeter|mm]] across), deep scars that extend into the dermis.<ref name=Levy2012/> Rolling scars are broader than ice-pick and boxcar scars (4–5&nbsp;mm across) and have a wave-like pattern of depth in the skin.<ref name=Levy2012/>

[[Hypertrophic scar]]s are uncommon and are characterized by increased collagen content after the abnormal healing response.<ref name=Levy2012/> They are described as firm and raised from the skin.<ref name=Levy2012/><ref name=Sobanko2012>{{cite journal | vauthors = Sobanko JF, Alster TS | title = Management of acne scarring, part I: a comparative review of laser surgical approaches | journal = American Journal of Clinical Dermatology | volume = 13 | issue = 5 | pages = 319–30 | date = October 2012 | pmid = 22612738 | doi = 10.2165/11598910-000000000-00000 | s2cid = 28374672 | type = Review }}</ref> Hypertrophic scars remain within the original margins of the wound, whereas [[keloid|keloid scars]] can form scar tissue outside of these borders.<ref name=Levy2012/> Keloid scars from acne occur more often in men and people with darker skin, and usually occur on the trunk of the body.<ref name=Levy2012/>