Editing Leprosy (section)

=== Classification ===
Several different approaches for classifying leprosy exist. There are similarities between the classification approaches.
* The World Health Organization (WHO) system distinguishes patients with 5 or fewer skin lesions and no bacilli in a skin smear as "paucibacillary" ("[[wikt:paucus#Latin|pauci]]-" refers to a small quantity) from patients with more lesions or detected bacilli as "multibacillary".<ref name="who-leprosy-factsheet-2025">{{Cite web |title=Leprosy |url=https://www.who.int/news-room/fact-sheets/detail/leprosy |access-date=2025-02-13 |website=www.who.int |language=en}}</ref> 
* The Ridley-Jopling scale provides five gradations.<ref name="pm hippopotamus id15176024">{{cite journal | vauthors = Singh N, Manucha V, Bhattacharya SN, Arora VK, Bhatia A | title = Pitfalls in the cytological classification of borderline leprosy in the Ridley-Jopling scale | journal = Diagnostic Cytopathology | volume = 30 | issue = 6 | pages = 386–388 | date = June 2004 | pmid = 15176024 | doi = 10.1002/dc.20012 | s2cid = 29757876 }}</ref><ref name="pmid5950347">{{cite journal | vauthors = Ridley DS, Jopling WH | title = Classification of leprosy according to immunity. A five-group system | journal = International Journal of Leprosy and Other Mycobacterial Diseases | volume = 34 | issue = 3 | pages = 255–273 | year = 1966 | pmid = 5950347 }}</ref><ref name="Andrews">{{cite book|title=Andrews' Diseases of the Skin: clinical Dermatology|url=https://archive.org/details/andrewsdiseasess00mdwi_659|url-access=limited| vauthors = James WD, Berger TG, Elston DM, Odom RB |publisher=Saunders Elsevier|year=2006|isbn=978-0-7216-2921-6|pages=[https://archive.org/details/andrewsdiseasess00mdwi_659/page/n354 344]–46}}</ref>
* The [[ICD-10]], though developed by the WHO, uses Ridley-Jopling and not the WHO system. It also adds an indeterminate ("I") entry.<ref name="news-medical">"What Is Leprosy?"| from News-Medical.Net – Latest Medical News and Research from Around the World. Web. 20 November 2010. {{cite news |url=http://www.news-medical.net/health/What-is-Leprosy.aspx |title=What is Leprosy? |newspaper=News-Medical.net |access-date=14 May 2013 |url-status=live |archive-url=https://web.archive.org/web/20130606033328/http://www.news-medical.net/health/What-is-Leprosy.aspx |archive-date=6 June 2013 |date=18 November 2009 }}.</ref>
* In [[Medical Subject Headings|MeSH]], three groupings are used.
{{Clear}}
{| class="wikitable"
|-
! WHO
! Ridley-Jopling
! [[ICD-10]]
! [[Medical Subject Headings|MeSH]]
! Description
! [[Lepromin]] test
|-
| Paucibacillary
| tuberculoid ("TT"),<br />borderline<br />tuberculoid ("BT")
| style="white-space:nowrap;"| A30.1, A30.2
| Tuberculoid
| It is characterized by one or more [[Hypopigmentation|hypopigmented]] skin macules and patches where skin sensations are lost because of damaged peripheral nerves that have been attacked by the human host's immune cells. TT is characterized by the formation of [[epithelioid cell]] granulomas with a large number of [[epithelioid cell]]s. In this form of leprosy, ''Mycobacterium leprae'' are either absent from the lesion or occur in very small numbers. This type of leprosy is most benign.<ref name="pmid22988457"/><ref name="pmid24937811">{{cite journal | vauthors = Lastória JC, Abreu MA | title = Leprosy: a review of laboratory and therapeutic aspects--part 2 | journal = Anais Brasileiros de Dermatologia | volume = 89 | issue = 3 | pages = 389–401 | date = 2014 | pmid = 24937811 | pmc = 4056695 | doi = 10.1590/abd1806-4841.20142460 | doi-access = free }}</ref>

| Positive
|-
| Multibacillary
| style="white-space:nowrap;"|midborderline<br />or<br />borderline ("BB")
| A30.3
| Borderline
| Borderline leprosy is of intermediate severity and is the most common form. Skin lesions resemble tuberculoid leprosy, but are more numerous and irregular; large patches may affect a whole limb, and peripheral nerve involvement with weakness and loss of sensation is common. This type is unstable and may become more like lepromatous leprosy or may undergo a reversal reaction, becoming more like the tuberculoid form.{{citation needed|date=May 2021}}
|Negative
|-
| Multibacillary
| borderline lepromatous ("BL"),<br />and lepromatous ("LL")
| A30.4, A30.5
| Lepromatous
| It is associated with symmetric skin [[lesion]]s, [[Nodule (medicine)|nodules]], [[Plaque (dermatology)|plaques]], thickened dermis, and frequent involvement of the nasal mucosa resulting in nasal congestion and [[epistaxis|nose bleeds]], but, typically, detectable nerve damage is late. Loss of eyebrows and lashes can be seen in advanced disease.<ref>{{Cite web|url=https://internationaltextbookofleprosy.org/chapter/diagnosis-leprosy|title=Clinical Diagnosis of Leprosy|author1=Kumar, Bhushan|author2=Uprety, Shraddha|author3=Dogra, Sunil|date=11 February 2016|website=International Textbook of Leprosy|access-date=12 February 2019|archive-date=13 February 2019|archive-url=https://web.archive.org/web/20190213064205/https://internationaltextbookofleprosy.org/chapter/diagnosis-leprosy|url-status=live}}</ref> LL is characterized by the absence of [[epithelioid cell]]s in the lesions. In this form of leprosy, ''Mycobacteria leprae'' are found in lesions in large numbers. This is the most unfavorable clinical variant of leprosy, which occurs with a generalized lesion of the skin, mucous membranes, eyes, peripheral nerves, lymph nodes, and internal organs.<ref name="pmid22988457" /><ref name="pmid24937811" /> [[Histoid leprosy]] is a rare variation of multibacillary, lepromatous leprosy.
| Negative
|}

Leprosy may also occur with only neural involvement, without skin lesions.<ref name="WHO Fact Sheet" /><ref name="pmid12883921">{{cite journal | vauthors = Jardim MR, Antunes SL, Santos AR, Nascimento OJ, Nery JA, Sales AM, Illarramendi X, Duppre N, Chimelli L, Sampaio EP, Sarno EP | title = Criteria for diagnosis of pure neural leprosy | journal = Journal of Neurology | volume = 250 | issue = 7 | pages = 806–809 | date = July 2003 | pmid = 12883921 | doi = 10.1007/s00415-003-1081-5 | s2cid = 20070335 }}</ref><ref name="pmid17120509">{{cite journal | vauthors = Mendiratta V, Khan A, Jain A | title = Primary neuritic leprosy: a reappraisal at a tertiary care hospital | journal = Indian Journal of Leprosy | volume = 78 | issue = 3 | pages = 261–267 | year = 2006 | pmid = 17120509 }}</ref><ref name="pmid10979277">{{cite journal | vauthors = Ishida Y, Pecorini L, Guglielmelli E | title = Three cases of pure neuritic (PN) leprosy at detection in which skin lesions became visible during their course | journal = Nihon Hansenbyo Gakkai Zasshi = Japanese Journal of Leprosy | volume = 69 | issue = 2 | pages = 101–106 | date = July 2000 | pmid = 10979277 | doi = 10.5025/hansen.69.101 | doi-access = free }}</ref><ref name="pmid8711979">{{cite journal | vauthors = Mishra B, Mukherjee A, Girdhar A, Husain S, Malaviya GN, Girdhar BK | title = Neuritic leprosy: further progression and significance | journal = Acta Leprologica | volume = 9 | issue = 4 | pages = 187–194 | year = 1995 | pmid = 8711979 }}</ref><ref name="pmid1406021">{{cite journal | vauthors = Talwar S, Jha PK, Tiwari VD | title = Neuritic leprosy: epidemiology and therapeutic responsiveness | journal = Leprosy Review | volume = 63 | issue = 3 | pages = 263–268 | date = September 1992 | pmid = 1406021 | doi = 10.5935/0305-7518.19920031 | doi-access = free }}</ref>