Editing Acne (section)

==Classification==
The severity of acne vulgaris (Gr. ἀκμή, "point" + L. ''vulgaris'', "common")<ref>{{cite encyclopedia |title="acne", "vulgar" |encyclopedia=Oxford English Dictionary |edition = 2nd |year= 2009 |medium=CD-ROM |publisher=Oxford University Press |location=Oxford}}</ref> can be classified as mild, moderate, or severe to determine an appropriate treatment regimen.<ref name="BMJ2013"/> There is no universally accepted scale for grading acne severity.<ref name="Zaenglein2018"/> The presence of clogged skin follicles (known as [[comedo]]nes) limited to the face with occasional inflammatory lesions defines mild acne.<ref name=BMJ2013/> Moderate severity acne is said to occur when a higher number of inflammatory [[papule]]s and [[pustule]]s occur on the face, compared to mild cases of acne, and appear on the trunk of the body.<ref name=BMJ2013/> Severe acne is said to occur when [[Nodule (dermatology)|nodules]] (the painful 'bumps' lying under the skin) are the characteristic facial lesions, and involvement of the trunk is extensive.<ref name=BMJ2013/><ref name=Fitzpatrick2012/>

The lesions are usually polymorphic, meaning they can take many forms, including open or closed comedones (commonly known as blackheads and whiteheads), papules, pustules, and even nodules or cysts so that these lesions often leave behind sequelae, or abnormal conditions resulting from a previous disease, such as scarring or hyperpigmentation.<ref name="pmid38650835"/>

Large nodules were previously called [[cyst]]s. The term ''nodulocystic'' has been used in the medical literature to describe severe cases of inflammatory acne.<ref name=Fitzpatrick2012>{{cite book| vauthors = Zaenglein AL, Graber EM, Thiboutot DM |year=2012|chapter=Chapter 80 Acne Vulgaris and Acneiform Eruptions|editor=Goldsmith, Lowell A. |editor2=Katz, Stephen I. |editor3=Gilchrest, Barbara A. |editor4=Paller, Amy S. |editor5=Lefell, David J. |editor6=Wolff, Klaus |title=Fitzpatrick's Dermatology in General Medicine|edition=8th|location=New York |publisher=McGraw-Hill|isbn=978-0-07-171755-7|pages=897–917}}</ref> True cysts are rare in those with acne, and the term ''severe nodular acne'' is now the preferred terminology.<ref name=Fitzpatrick2012/>

''Acne inversa'' (L.  invertō, "upside-down") and ''acne rosacea'' (rosa, "rose-colored" + -āceus, "forming") are not forms of acne and are alternate names that respectively refer to the skin conditions [[hidradenitis suppurativa]] (HS) and [[rosacea]].<ref name="Dessinioti2014">{{cite journal | vauthors = Dessinioti C, Katsambas A, Antoniou C | title = Hidradenitis suppurrativa (acne inversa) as a systemic disease | journal = Clinics in Dermatology | volume = 32 | issue = 3 | pages = 397–408 | date = May–June 2014 | pmid = 24767187 | doi = 10.1016/j.clindermatol.2013.11.006 | type = Review }}</ref><ref name="Moustafa2014">{{cite journal | vauthors = Moustafa FA, Sandoval LF, Feldman SR | title = Rosacea: new and emerging treatments | journal = Drugs | volume = 74 | issue = 13 | pages = 1457–65 | date = September 2014 | pmid = 25154627 | doi = 10.1007/s40265-014-0281-x | s2cid = 5205305 | type = Review }}</ref><ref name="Dessinioti2014B">{{cite journal | vauthors = Dessinioti C, Antoniou C, Katsambas A | title = Acneiform eruptions | journal = Clinics in Dermatology | volume = 32 | issue = 1 | pages = 24–34 | date = January–February 2014 | pmid = 24314375 | doi = 10.1016/j.clindermatol.2013.05.023 | type = Review }}</ref> Although HS shares certain overlapping features with acne vulgaris, such as a tendency to clog skin follicles with skin cell debris, the condition otherwise lacks the hallmark features of acne and is therefore considered a distinct skin disorder.<ref name="Dessinioti2014"/>