Editing Alopecia areata

{{Short description|Medical condition}}
{{Use dmy dates|date=June 2022}}
{{cs1 config|name-list-style=vanc|display-authors=6}}
{{Infobox medical condition (new)
| name          = Alopecia areata
| pronounce     = {{IPAc-en|%|{|l|@|"|p|i:|S|(|i|)|@|_|%|{|r|i|"|A:|t|@}},<br>also {{IPAc-en|%|{|l|oU|-|,_|-|s|i|@|-|,_|-|"|eI|t|@}}<ref>{{Cite book|title=The Chambers Dictionary|publisher=Chambers|year=2003|isbn=0-550-10105-5|edition=9th|chapter=alopecia}}</ref><ref>{{Cite book|title=Collins English Dictionary|publisher=HarperCollins|year=2018|isbn=978-0-008-28437-4|edition=13th|chapter=alopecia}}</ref><ref>{{Cite web|title=Definition of alopecia|url=https://www.dictionary.com/browse/alopecia|access-date=14 February 2022|website=Dictionary.com|archive-date=28 March 2022|archive-url=https://web.archive.org/web/20220328230916/https://www.dictionary.com/browse/alopecia|url-status=live}}</ref><ref>{{cite Merriam-Webster|alopecia|access-date=25 March 2022}}</ref>
| synonyms      = Alopecia Celsi, vitiligo capitis, Jonston's alopecia<ref name=NORD2004>{{cite web|title=Alopecia Areata - NORD (National Organization for Rare Disorders)|url=https://rarediseases.org/rare-diseases/alopecia-areata/|website=NORD (National Organization for Rare Disorders)|access-date=10 July 2017|date=2004|url-status = live|archive-url=https://web.archive.org/web/20170221044421/https://rarediseases.org/rare-diseases/alopecia-areata/|archive-date=21 February 2017}}</ref>
| image         = Allopecia areata.JPG
| caption       = Alopecia areata seen on the back of the scalp
| specialty     = [[Dermatology]] [[Immunology]]<ref>{{cite web | title=Alopecia Areata | website=National Institute of Arthritis and Musculoskeletal and Skin Diseases | date=4 April 2017 | url=https://www.niams.nih.gov/health-topics/alopecia-areata | access-date=17 November 2023}}</ref>
| symptoms      = Areas of [[hair loss]], usually on the scalp<ref name=NIH2016/>
| complications = 
| onset         = Childhood<ref name=NIH2016/>
| duration      = 
| types         = 
| causes        = [[Autoimmune disease|Autoimmune]]<ref name=NIH2016/>
| risks         = Family history, [[female sex]], [[rheumatoid arthritis]], [[diabetes mellitus type 1|type 1 diabetes]], [[celiac disease]]<ref name=NIH2016/><ref name=HordinskyJunqueira2015 /><ref name="occurrence" />
| diagnosis     = 
| differential  = [[Trichotillomania]], [[alopecia mucinosa]], [[postpartum alopecia]]<ref name=NORD2004/>
| prevention    = 
| treatment     = [[Sunscreen]], head coverings to protect from sun and cold<ref name=NIH2016/>
| medication    = topical [[minoxidil]]<ref name="Freire2019"/> and [[triamcinolone]] injections<ref name="Yee2020JAAD"/>
| prognosis     = Does not affect [[life expectancy]]<ref name=NIH2016/><ref name=NORD2004/>
| frequency     = ~2% (US)<ref name=NIH2016/>
| deaths        = 
}}

<!-- Definition and symptoms -->
'''Alopecia areata''' ('''AA'''), also known as '''spot baldness''', is a condition in which [[hair loss|hair is lost]] from some or all areas of the body.<ref name="Erjavec">{{cite journal | vauthors = Erjavec SO, Gelfman S, Abdelaziz AR, Lee EY, Monga I, Alkelai A, Ionita-Laza I, Petukhova L, Christiano AM | title = Whole exome sequencing in Alopecia Areata identifies rare variants in KRT82 | journal = Nature Communications | volume = 13 | issue = 1 | pages = 800 | date = February 2022 | pmid = 35145093 | pmc = 8831607 | doi = 10.1038/s41467-022-28343-3 | bibcode = 2022NatCo..13..800E }}</ref><ref name=NORD2004/> It often results in a few [[Baldness|bald spots]] on the scalp, each about the size of a coin.<ref name=NIH2016/> [[Psychological stress]] and illness are possible factors in bringing on alopecia areata in individuals at risk, but in most cases there is no obvious trigger.<ref name=NIH2016/> People are generally otherwise healthy.<ref name=NIH2016/> In a few cases, all the hair on the scalp is lost (''[[alopecia totalis]]''), or all body hair is lost (''[[alopecia universalis]]''). Hair loss can be permanent or temporary.<ref name=NIH2016/><ref name=NORD2004/>

<!-- Cause and diagnosis -->
Alopecia areata is believed to be an [[autoimmune disease]] resulting from a breach in the [[immune privilege]] of the [[hair follicle]]s.<ref name="Erjavec"/><ref name=BJD2018>{{cite journal | vauthors = Rajabi F, Drake LA, Senna MM, Rezaei N | title = Alopecia areata: a review of disease pathogenesis | journal = The British Journal of Dermatology | volume = 179 | issue = 5 | pages = 1033–1048 | date = November 2018 | pmid = 29791718 | doi = 10.1111/bjd.16808 | s2cid = 43940520 }}</ref> Risk factors include a family history of the condition.<ref name=NIH2016/> Among [[identical twins]], if one is affected, the other has about a 50% chance of also being affected.<ref name=NIH2016/> The underlying mechanism involves failure by the body to recognize its own cells, with subsequent immune-mediated destruction of the [[hair follicle]].<ref name=NIH2016>{{cite web| vauthors = Fleming R |title=Questions and Answers About Alopecia Areata|url=https://www.niams.nih.gov/Health_Info/alopecia_areata/default.asp|website=NIAMS|access-date=10 July 2017|date=May 2016|url-status = live|archive-url=https://web.archive.org/web/20170704182250/https://www.niams.nih.gov/Health_Info/Alopecia_Areata/default.asp|archive-date=4 July 2017}}</ref>

<!-- Treatment and prognosis -->
No cure for the condition is known.<ref name=NIH2016/> Some treatments, particularly [[triamcinolone]] injections and 5% [[minoxidil]] topical creams,<ref name="Yee2020JAAD">{{cite journal | vauthors = Yee BE, Tong Y, Goldenberg A, Hata T | title = Efficacy of different concentrations of intralesional triamcinolone acetonide for alopecia areata: A systematic review and meta-analysis | journal = Journal of the American Academy of Dermatology | volume = 82 | issue = 4 | pages = 1018–1021 | date = April 2020 | pmid = 31843657 | doi = 10.1016/j.jaad.2019.11.066 | s2cid = 209389315 }}</ref><ref name="Freire2019">{{cite journal | vauthors = Freire PC, Riera R, Martimbianco AL, Petri V, Atallah AN | title = Minoxidil for patchy alopecia areata: systematic review and meta-analysis | journal = Journal of the European Academy of Dermatology and Venereology | volume = 33 | issue = 9 | pages = 1792–1799 | date = September 2019 | pmid = 30835901 | doi = 10.1111/jdv.15545 | s2cid = 73460786 }}</ref> are effective in speeding hair regrowth.<ref name=NIH2016/><ref name=NORD2004/> [[Sunscreen]], head coverings to protect from cold and sun, and [[glasses]], if the [[eyelashes]] are missing, are also recommended.<ref name=NIH2016/> In more than 50% of cases of sudden-onset localized "patchy" disease, hair regrows within a year.<ref name="Paggioli2022">{{cite journal | vauthors = Paggioli I, Moss J | title = Alopecia Areata: Case report and review of pathophysiology and treatment with Jak inhibitors | journal = Journal of Autoimmunity | volume = 133 | pages = 102926 | date = December 2022 | pmid = 36335798 | doi = 10.1016/j.jaut.2022.102926 | s2cid = 253320808 }}</ref><ref name="Alkhalifah2010">{{cite journal | vauthors = Alkhalifah A, Alsantali A, Wang E, McElwee KJ, Shapiro J | title = Alopecia areata update: part I. Clinical picture, histopathology, and pathogenesis | journal = Journal of the American Academy of Dermatology | volume = 62 | issue = 2 | pages = 177–88, quiz 189–90 | date = February 2010 | pmid = 20115945 | doi = 10.1016/j.jaad.2009.10.032 }}</ref><ref name=NIH2016/> In patients with only one or two patches, this one-year recovery will occur in up to 80%.<ref name="Spano2015">{{cite journal | vauthors = Spano F, Donovan JC | title = Alopecia areata: Part 1: pathogenesis, diagnosis, and prognosis | journal = Canadian Family Physician | volume = 61 | issue = 9 | pages = 751–755 | date = September 2015 | pmid = 26371097 | pmc = 4569104 }}</ref><ref name="Mounsey2009">{{cite journal | vauthors = Mounsey AL, Reed SW | title = Diagnosing and treating hair loss | journal = American Family Physician | volume = 80 | issue = 4 | pages = 356–362 | date = August 2009 | pmid = 19678603 | url = https://www.aafp.org/pubs/afp/issues/2009/0815/p356.html | access-date = 16 November 2022 | url-status = live | archive-url = https://web.archive.org/web/20221116210414/https://www.aafp.org/pubs/afp/issues/2009/0815/p356.html | archive-date = 16 November 2022 }}</ref> However, many people will have more than one episode over the course of a lifetime.<ref name="Alkhalifah2010"/> In many patients, hair loss and regrowth occurs simultaneously over the course of several years.<ref name=NIH2016/> Among those in whom all body hair is lost, fewer than 10% recover.<ref name=Bei2018>{{cite book | vauthors = Beigi PK |title=Alopecia Areata: A Clinician's Guide |date=2018 |publisher=Springer |isbn=9783319721347 |page=14 |url=https://books.google.com/books?id=DtNeDwAAQBAJ&q=978-3-319-72133-0&pg=PA14 |access-date=1 October 2020 |archive-date=14 January 2023 |archive-url=https://web.archive.org/web/20230114105807/https://books.google.com/books?id=DtNeDwAAQBAJ&q=978-3-319-72133-0&pg=PA14 |url-status=live }}</ref>

<!-- Epidemiology -->
About 0.15% of people are affected at any one time, and 2% of people are affected at some point in time.<ref name=NIH2016/><ref name=Bei2018/> Onset is usually in childhood.<ref name=NIH2016/> Females are affected at higher rates than males.<ref name="occurrence" />

== Signs and symptoms ==
[[File:Alopecia areata.jpg|thumbnail|Alopecia areata]]

Typical first symptoms of alopecia areata are small bald patches. The underlying skin is unscarred and looks superficially normal. Although these patches can take many shapes, they are usually round or oval.<ref name="Fitz2">{{cite book | vauthors = Freedberg IM, Fitzpatrick TB | title = Fitzpatrick's dermatology in medicine | publisher = McGraw-Hill, Medical Pub. Division | location=New York |year=2003 |isbn=978-0-07-138076-8}}{{Page needed|date=September 2010}}</ref> Alopecia areata most often affects the scalp and beard, but may occur on any part of the body with hair.<ref name=merck/> Different areas of the skin may exhibit hair loss and regrowth at the same time. The disease may also go into remission for a time, or may be permanent. It is common in children.{{citation needed|date=August 2020}}

The area of hair loss may [[paresthesia|tingle]] or be mildly painful.<ref name=aocd>{{cite web | work = American Osteopathic College of Dermatology | url = http://www.aocd.org/skin/dermatologic_diseases/alopecia_areata.html | title = Alopecia Areata | archive-url = https://web.archive.org/web/20071213205902/http://www.aocd.org/skin/dermatologic_diseases/alopecia_areata.html | archive-date=13 December 2007 }} Dermatologic Disease Database. Aocd.org. Retrieved on 3 December 2007.</ref> The hair tends to fall out over a short period of time, with the loss commonly occurring more on one side of the scalp than the other.<ref name=draelos/>

Exclamation point hairs, narrower along the length of the strand closer to the base, producing a characteristic "exclamation point" appearance, are often present.<ref name=draelos>{{cite web | vauthors = Draelos ZD | date = 30 August 2007 | url = http://www.medicinenet.com/alopecia_areata/article.htm | title = Alopecia Areata | archive-url = https://web.archive.org/web/20071208050019/http://www.medicinenet.com/alopecia_areata/article.htm | archive-date=8 December 2007 | work = MedicineNet.com | access-date = 2 December 2007 }}</ref> These hairs are very short (3–4&nbsp;mm), and can be seen surrounding the bald patches.<ref name="Mounsey2009" />

When healthy hair is pulled out, at most a few should come out, and ripped hair should not be distributed evenly across the tugged portion of the scalp. In cases of alopecia areata, hair tends to pull out more easily along the edge of the patch where the follicles are already being attacked by the body's immune system than away from the patch where they are still healthy.<ref>{{cite journal | vauthors = Wasserman D, Guzman-Sanchez DA, Scott K, McMichael A | title = Alopecia areata | journal = International Journal of Dermatology | volume = 46 | issue = 2 | pages = 121–131 | date = February 2007 | pmid = 17269961 | doi = 10.1111/j.1365-4632.2007.03193.x | s2cid = 57279630 }}</ref>

Nails may have pitting or [[trachyonychia]].<ref name=merck/> Onychoptosis defluvium, also known as alopecia unguium, is casting off the nail seen in association with alopecia areata.<ref name="Fitz2003">>{{cite book | vauthors = Freedberg IM, Eisen AZ, Wolff K, Austen KF, Goldsmith LA, Katz S |title=Fitzpatrick's dermatology in general medicine |date=2003 |publisher=McGraw-Hill, Medical Pub. Division |location=New York |isbn=0-07-138076-0 |edition=6th}}</ref>{{rp|660}}

== Causes ==
[[File:Alopecia areata.svg|thumb|In alopecia areata, a hair follicle is attacked by the immune system. T-cells swarm the roots, killing the follicle. This causes the hair to fall out and parts of the head to become bald.]]

Alopecia areata is thought to be a systemic autoimmune disorder in which the body attacks its own anagen [[hair follicle]]s and suppresses or stops hair growth.<ref name=draelos/> For example, [[T cell]] [[lymphocytes]] cluster around affected follicles, causing inflammation and subsequent hair loss. Hair follicles in a normal state are thought to be kept secure from the immune system, a phenomenon called immune privilege. A breach in this immune privilege state is considered as the cause of alopecia areata.<ref name=BJD2018/> A few cases of babies being born with [[congenital]] alopecia areata have been reported.<ref name=LenanePope2005>{{cite journal | vauthors = Lenane P, Pope E, Krafchik B | title = Congenital alopecia areata | journal = Journal of the American Academy of Dermatology | volume = 52 | issue = 2 Suppl 1 | pages = 8–11 | date = February 2005 | pmid = 15692503 | doi = 10.1016/j.jaad.2004.06.024 | type = Case Reports. Review | quote = We believe AA should be classified not only as an acquired, but also a congenital form of nonscarring hair loss. It may well be more common than is thought because of lack of recognition }}</ref> It is recognized as a type 1 inflammatory disease.<ref name="Fukuyama Ito Ohyama 2021 pp. 19–36">{{cite journal | vauthors = Fukuyama M, Ito T, Ohyama M | title = Alopecia areata: Current understanding of the pathophysiology and update on therapeutic approaches, featuring the Japanese Dermatological Association guidelines | journal = The Journal of Dermatology | volume = 49 | issue = 1 | pages = 19–36 | date = January 2022 | pmid = 34709679 | doi = 10.1111/1346-8138.16207 | s2cid = 240073350 }}</ref>

Alopecia areata is not [[Infectious disease|contagious]].<ref name=draelos/> It occurs more frequently in people who have affected family members, suggesting [[heredity]] may be a factor.<ref name=draelos/> Strong evidence of genetic association with increased risk for alopecia areata was found by studying families with two or more affected members. This study identified at least four regions in the genome that are likely to contain these genes.<ref>{{cite journal | vauthors = Martinez-Mir A, Zlotogorski A, Gordon D, Petukhova L, Mo J, Gilliam TC, Londono D, Haynes C, Ott J, Hordinsky M, Nanova K, Norris D, Price V, Duvic M, Christiano AM | title = Genomewide scan for linkage reveals evidence of several susceptibility loci for alopecia areata | journal = American Journal of Human Genetics | volume = 80 | issue = 2 | pages = 316–328 | date = February 2007 | pmid = 17236136 | pmc = 1785354 | doi = 10.1086/511442 }}</ref> In addition, alopecia areata shares genetic risk factors with other autoimmune diseases, including [[rheumatoid arthritis]], [[diabetes mellitus type 1|type 1 diabetes]], and [[celiac disease]].<ref name=HordinskyJunqueira2015>{{cite journal | vauthors = Hordinsky M, Junqueira AL | title = Alopecia areata update | journal = Seminars in Cutaneous Medicine and Surgery | volume = 34 | issue = 2 | pages = 72–75 | date = June 2015 | pmid = 26176283 | doi = 10.12788/j.sder.2015.0160 | doi-broken-date = 1 November 2024 | type = Review | doi-access = free }}{{open access}}</ref> It may be the only manifestation of celiac disease.<ref name=CaproniBonciolini2012>{{cite journal | vauthors = Caproni M, Bonciolini V, D'Errico A, Antiga E, Fabbri P | title = Celiac disease and dermatologic manifestations: many skin clue to unfold gluten-sensitive enteropathy | journal = Gastroenterology Research and Practice | volume = 2012 | pages = 952753 | year = 2012 | pmid = 22693492 | pmc = 3369470 | doi = 10.1155/2012/952753 | doi-access = free | type = Review }}</ref><ref name=TackVerbeek2010>{{cite journal | vauthors = Tack GJ, Verbeek WH, Schreurs MW, Mulder CJ | title = The spectrum of celiac disease: epidemiology, clinical aspects and treatment | journal = Nature Reviews. Gastroenterology & Hepatology | volume = 7 | issue = 4 | pages = 204–213 | date = April 2010 | pmid = 20212505 | doi = 10.1038/nrgastro.2010.23 | type = Review | s2cid = 7951660 }}</ref>

Lifestyle factors such as smoking, sleep quality, and obesity may also contribute to the onset and progression of alopecia areata.<ref name="Sánchez-Pellicer 1860">{{cite journal | vauthors = Sánchez-Pellicer P, Navarro-Moratalla L, Núñez-Delegido E, Agüera-Santos J, Navarro-López V | title = How Our Microbiome Influences the Pathogenesis of Alopecia Areata | journal = Genes | volume = 13 | issue = 10 | pages = 1860 | date = October 2022 | pmid = 36292745 | pmc = 9601531 | doi = 10.3390/genes13101860 | doi-access = free }}</ref> Studies indicate that smokers have a higher risk of developing the condition, potentially due to tobacco-induced [[T helper 17 cell|Th17-mediated inflammation]] in hair follicles.<ref>{{cite journal | vauthors = Dai YX, Yeh FY, Shen YJ, Tai YH, Chou YJ, Chang YT, Chen TJ, Li CP, Wu CY | title = Cigarette Smoking, Alcohol Consumption, and Risk of Alopecia Areata: A Population-Based Cohort Study in Taiwan | journal = American Journal of Clinical Dermatology | volume = 21 | issue = 6 | pages = 901–911 | date = December 2020 | pmid = 32761499 | doi = 10.1007/s40257-020-00547-7 }}</ref><ref>{{cite journal | vauthors = Melnik BC, John SM, Chen W, Plewig G | title = T helper 17 cell/regulatory T-cell imbalance in hidradenitis suppurativa/acne inversa: the link to hair follicle dissection, obesity, smoking and autoimmune comorbidities | journal = The British Journal of Dermatology | volume = 179 | issue = 2 | pages = 260–272 | date = August 2018 | pmid = 29573406 | doi = 10.1111/bjd.16561 }}</ref> While some research suggests a link between [[sleep disorder]]s and alopecia areata, findings remain inconclusive.<ref name="Sánchez-Pellicer 1860"/> However, since sleep disturbances impact immune function, they may play a role in disease pathogenesis.<ref>{{cite journal | vauthors = Besedovsky L, Lange T, Haack M | title = The Sleep-Immune Crosstalk in Health and Disease | journal = Physiological Reviews | volume = 99 | issue = 3 | pages = 1325–1380 | date = July 2019 | pmid = 30920354 | doi = 10.1152/physrev.00010.2018 }}</ref> Additionally, obesity is associated with an increased risk of alopecia areata, likely due to [[adipokine]] dysregulation, which promotes chronic low-grade inflammation and alters immune response, as seen in other inflammatory skin conditions.<ref>{{cite journal | vauthors = Hagino T, Okazaki S, Serizawa N, Suzuki K, Kaga M, Otsuka Y, Mikami E, Hoashi T, Saeki H, Matsuda H, Mitsui H, Kanda N | title = Dietary Habits in Japanese Patients with Alopecia Areata | journal = Clinical, Cosmetic and Investigational Dermatology | volume = 14 | pages = 1579–1591 | date = October 2021 | pmid = 34737597 | doi = 10.2147/CCID.S335440 | doi-access = free | pmc = 8560057 }}</ref><ref>{{cite journal | vauthors = Taylor EB | title = The complex role of adipokines in obesity, inflammation, and autoimmunity | journal = Clinical Science | volume = 135 | issue = 6 | pages = 731–752 | date = March 2021 | pmid = 33729498 | doi = 10.1042/CS20200895 | pmc = 7969664 }}</ref>

Endogenous [[retinoid]]s metabolic defect is a key part of the pathogenesis of the alopecia areata.<ref>{{cite journal | vauthors = Duncan FJ, Silva KA, Johnson CJ, King BL, Szatkiewicz JP, Kamdar SP, Ong DE, Napoli JL, Wang J, King LE, Whiting DA, McElwee KJ, Sundberg JP, Everts HB | title = Endogenous retinoids in the pathogenesis of alopecia areata | journal = The Journal of Investigative Dermatology | volume = 133 | issue = 2 | pages = 334–343 | date = February 2013 | pmid = 23014334 | pmc = 3546144 | doi = 10.1038/jid.2012.344 }}</ref>

In 2010, a genome-wide association study was completed that identified 129 single nucleotide polymorphisms that were associated with alopecia areata. The genes that were identified include those involved in
controlling the activation and proliferation of regulatory T cells, cytotoxic T lymphocyte-associated antigen 4, interleukin-2, interleukin-2 receptor A, and Eos (also known as Ikaros family zinc finger 4), as well as the human leukocyte antigen. The study also identified two genes, ''PRDX5'' and ''STX17'', that are expressed in the hair follicle.<ref>{{cite journal | vauthors = Petukhova L, Duvic M, Hordinsky M, Norris D, Price V, Shimomura Y, Kim H, Singh P, Lee A, Chen WV, Meyer KC, Paus R, Jahoda CA, Amos CI, Gregersen PK, Christiano AM | title = Genome-wide association study in alopecia areata implicates both innate and adaptive immunity | journal = Nature | volume = 466 | issue = 7302 | pages = 113–117 | date = July 2010 | pmid = 20596022 | pmc = 2921172 | doi = 10.1038/nature09114 | bibcode = 2010Natur.466..113P }}</ref>

There is emerging evidence suggesting a possible link between AA and vaccinations, including influenza, zoster, and [[Human papillomavirus infection|human papillomavirus (HPV)]] vaccines.<ref>{{cite journal | vauthors = Chu CH, Cheng YP, Chan JY | title = Alopecia Areata After Vaccination: Recurrence with Rechallenge | journal = Pediatric Dermatology | volume = 33 | issue = 3 | pages = e218-e219 | date = May 2016 | pmid = 27071855 | doi = 10.1111/pde.12849 }}</ref> One possible explanation is that vaccinations could trigger immune system activation, which has been observed to exacerbate preexisting autoimmune or autoinflammatory conditions in at-risk populations.<ref>{{cite journal | vauthors = Terracina KA, Tan FK | title = Flare of rheumatoid arthritis after COVID-19 vaccination | journal = The Lancet. Rheumatology | volume = 3 | issue = 7 | pages = e469-e470 | date = July 2021 | pmid = 33817664 | pmc = 8009616 | doi = 10.1016/S2665-9913(21)00108-9 }}</ref> A small study observed hair loss exacerbation in three patients following COVID-19 [[MRNA vaccine|mRNA vaccinations]] ([[Pfizer–BioNTech COVID-19 vaccine|Pfizer-BioNTech]] and [[Moderna COVID-19 vaccine|Moderna]]).<ref name="COVID-19 vaccination related exacer">{{cite journal | vauthors = Babadjouni A, Phong CH, Nguyen C, Mesinkovska NA | title = COVID-19 vaccination related exacerbations of hair loss in patients with moderate-to-severe alopecia areata on systemic therapy | journal = JAAD Case Reports | volume = 29 | pages = 181–185 | date = November 2022 | pmid = 36035747 | pmc = 9391088 | doi = 10.1016/j.jdcr.2022.08.016 }}</ref> These patients, who were younger on average (30.6 years) compared to unaffected individuals (37.2 years), experienced worsening hair loss within two weeks post-vaccination.<ref name="COVID-19 vaccination related exacer"/> Similar cases have been reported with the [[Oxford–AstraZeneca COVID-19 vaccine|AstraZeneca]] and [[Janssen COVID-19 vaccine|Johnson & Johnson]] COVID-19 vaccines.<ref>{{cite journal | vauthors = Essam R, Ehab R, Al-Razzaz R, Khater MW, Moustafa EA | title = Alopecia areata after ChAdOx1 nCoV-19 vaccine (Oxford/AstraZeneca): a potential triggering factor? | journal = Journal of Cosmetic Dermatology | volume = 20 | issue = 12 | pages = 3727–3729 | date = December 2021 | pmid = 34559937 | pmc = 8661988 | doi = 10.1111/jocd.14459 }}</ref> However, AA flares have also been linked to [[COVID-19|SARS-CoV-2 infection]], either as an exacerbation of preexisting disease or a new diagnosis.<ref name="COVID-19 vaccination related exacer"/> In the study's non-vaccinated AA cohort, the only observed case of hair loss worsening occurred after a COVID-19 infection.<ref name="COVID-19 vaccination related exacer"/> While causality remains unclear, these findings emphasize the need for further research into the relationship between vaccinations and AA progression.

A psychodermatological connection is noted with impairment in psychiatric comorbidities including mental well-being, self esteem and mental disorders acting as pathogenic triggers for alopecia areata.<ref name="Strazzulla Wang Avila Lo Sicco 2018 pp. 1–12">{{cite journal | vauthors = Strazzulla LC, Wang EH, Avila L, Lo Sicco K, Brinster N, Christiano AM, Shapiro J | title = Alopecia areata: Disease characteristics, clinical evaluation, and new perspectives on pathogenesis | journal = Journal of the American Academy of Dermatology | volume = 78 | issue = 1 | pages = 1–12 | date = January 2018 | pmid = 29241771 | doi = 10.1016/j.jaad.2017.04.1141 | publisher = Elsevier BV }}</ref><ref name="Lee Lee Lee Lee 2019 pp. 466–477.e16">{{cite journal | vauthors = Lee S, Lee H, Lee CH, Lee WS | title = Comorbidities in alopecia areata: A systematic review and meta-analysis | journal = Journal of the American Academy of Dermatology | volume = 80 | issue = 2 | pages = 466–477.e16 | date = February 2019 | pmid = 30031145 | doi = 10.1016/j.jaad.2018.07.013 | publisher = Elsevier BV | s2cid = 51707882 }}</ref><ref name="Torales Castaldelli-Maia Ventriglio Almirón-Santacruz 2021 pp. 2318–2323">{{cite journal | vauthors = Torales J, Castaldelli-Maia JM, Ventriglio A, Almirón-Santacruz J, Barrios I, O'Higgins M, García O, Navarro R, Melgarejo O, Jafferany M | title = Alopecia areata: A psychodermatological perspective | journal = Journal of Cosmetic Dermatology | volume = 21 | issue = 6 | pages = 2318–2323 | date = June 2022 | pmid = 34449973 | doi = 10.1111/jocd.14416 | s2cid = 237340798 }}</ref><ref name="Minokawa Sawada Nakamura 2022 p=1038">{{cite journal | vauthors = Minokawa Y, Sawada Y, Nakamura M | title = Lifestyle Factors Involved in the Pathogenesis of Alopecia Areata | journal = International Journal of Molecular Sciences | volume = 23 | issue = 3 | page = 1038 | date = January 2022 | pmid = 35162962 | pmc = 8835065 | doi = 10.3390/ijms23031038 | doi-access = free }}</ref>

== Diagnosis ==

Alopecia areata is usually diagnosed based on clinical features.

[[Trichoscopy]] may aid in establishing the diagnosis. In alopecia areata, trichoscopy shows regularly distributed "yellow dots" ([[hyperkeratotic]] plugs), small exclamation-mark hairs, and "black dots" (destroyed hairs in the hair follicle opening).<ref>{{cite journal | vauthors = Rudnicka L, Olszewska M, Rakowska A, Kowalska-Oledzka E, Slowinska M | title = Trichoscopy: a new method for diagnosing hair loss | journal = Journal of Drugs in Dermatology | volume = 7 | issue = 7 | pages = 651–654 | date = July 2008 | pmid = 18664157 }}</ref>

Oftentimes, however, discrete areas of hair loss surrounded by exclamation mark hairs is sufficient for clinical diagnosis of alopecia areata. Sometimes, reddening of the skin, [[erythema]], may also be present in the balding area.<ref name="Bei2018" />

A biopsy is rarely needed to make the diagnosis or aid in the management of alopecia areata. [[Histologic]] findings may include peribulbar [[lymphocytic]] infiltration resembling a "swarm of bees", a shift in the [[anagen]]-to-telogen ratio towards telogen, and dilated follicular infundibulae.<ref name=HordinskyJunqueira2015 /> Other helpful findings can include pigment incontinence in the [[hair bulb]] and follicular stelae. Occasionally, in inactive alopecia areata, no inflammatory infiltrates are found.{{citation needed|date=March 2015}}

=== Classification ===
[[File:Fox Plate V.jpg|thumb|Varying degrees of alopecia areata, along with alopecia totalis]]

Commonly, alopecia areata involves hair loss in one or more round spots on the scalp.<ref name=draelos/><ref name="Lookingbill">{{cite book | vauthors = Marks JG, Miller J | year = 2006 | title = Lookingbill and Marks' Principles of Dermatology | edition = 4th | publisher = Elsevier Inc. | isbn = 978-1-4160-3185-7 }}.{{page needed|date=March 2015}}</ref>
* Hair may also be lost more diffusely over the whole scalp, in which case the condition is called diffuse alopecia areata.<ref name=draelos/>
* Alopecia areata monolocularis describes baldness in only one spot. It may occur anywhere on the head.
* Alopecia areata multilocularis refers to multiple areas of hair loss.
* [[Ophiasis]] refers to hair loss in the shape of a wave at the circumference of the head.
* The disease may be limited only to the beard, in which case it is called alopecia areata barbae.<ref name=draelos/>
* If the person loses all the hair on the scalp, the disease is then called [[alopecia areata totalis]].<ref name=NIH2016/>
* If all body hair, including [[pubic hair]], is lost, the diagnosis then becomes [[alopecia areata universalis]].<ref name=NIH2016/>
Alopecia areata totalis and universalis are rare.<ref name=WebMD>{{cite web | url = http://www.webmd.com/skin-problems-and-treatments/alopecia-areata | title = Skin Conditions: Alopecia Areata | archive-url = https://web.archive.org/web/20071217145113/http://www.webmd.com/skin-problems-and-treatments/alopecia-areata | archive-date=17 December 2007 | work = WebMD | access-date = 2 December 2007 }}</ref>

== Treatment ==
The objective assessment of treatment efficacy is very difficult and spontaneous remission is unpredictable, but if the affected area is patchy, the hair may regrow spontaneously in many cases.<ref name=Shapiro2013>{{cite journal | vauthors = Shapiro J | title = Current treatment of alopecia areata | journal = The Journal of Investigative Dermatology. Symposium Proceedings | volume = 16 | issue = 1 | pages = S42–S44 | date = December 2013 | pmid = 24326551 | doi = 10.1038/jidsymp.2013.14 | type = Review | doi-access = free }}{{open access}}</ref> None of the existing therapeutic options are curative or preventive.<ref name=Shapiro2013 /> A 2020 systematic review showed greater than 50% hair regrowth in 80.9% of patients treated with 5&nbsp;mg/mL [[triamcinolone]] injections.<ref name="Yee2020JAAD"/> A [[Cochrane collaboration|Cochrane]]-style systematic review published in 2019 showed 5% topical [[minoxidil]] was more than eight times more associated with >50% hair regrowth at 6 months compared to placebo.<ref name="Freire2019"/> In cases of severe hair loss, limited success has been achieved by using the [[corticosteroid]] medications [[clobetasol]] or [[fluocinonide]] as an injection or cream. Application of corticosteroid creams to the affected skin is less effective and takes longer to produce results. Steroid injections are commonly used in sites where the areas of hair loss on the head are small or especially where eyebrow hair has been lost. Whether they are effective is uncertain.{{citation needed|date=June 2018}} Some other medications that have been used are [[minoxidil]], Elocon (mometasone) ointment (steroid cream), irritants ([[anthralin]] or topical [[coal tar]]), and topical immunotherapy [[ciclosporin]], sometimes in different combinations. Topical corticosteroids frequently fail to enter the skin deeply enough to affect the hair bulbs, which are the treatment target,<ref name=merck/> and small lesions typically also regrow spontaneously. Oral corticosteroids may decrease the hair loss, but only for the period during which they are taken, and these medications can cause serious [[adverse effect (medicine)|side effects]].<ref name=merck/> No one treatment is effective in all cases, and some individuals may show no response to any treatment.<ref>{{cite journal | vauthors = Alsantali A | title = Alopecia areata: a new treatment plan | journal = Clinical, Cosmetic and Investigational Dermatology | volume = 4 | pages = 107–115 | date = July 2011 | pmid = 21833161 | pmc = 3149478 | doi = 10.2147/CCID.S22767 | doi-access = free }}</ref>

For more severe cases, studies have shown promising results with the individual use of the immunosuppressant methotrexate or adjunct use with corticosteroids.<ref>{{cite journal | vauthors = Anuset D, Perceau G, Bernard P, Reguiai Z | title = Efficacy and Safety of Methotrexate Combined with Low- to Moderate-Dose Corticosteroids for Severe Alopecia Areata | journal = Dermatology | volume = 232 | issue = 2 | pages = 242–248 | date = 2016 | pmid = 26735937 | doi = 10.1159/000441250 | s2cid = 207742214 }}</ref>

When alopecia areata is associated with [[celiac disease]], treatment with a [[gluten-free diet]] allows for complete and permanent regrowth of scalp and other body hair in many people, but in others, remissions and recurrences are seen.<ref name=CaproniBonciolini2012 /> This improvement is probably due to the normalization of the [[immune response]] as a result of [[gluten]] withdrawal from the diet.<ref name=CaproniBonciolini2012 />

In June 2022, the U.S. [[Food and Drug Administration]] (FDA) authorized [[baricitinib]], a [[Janus kinase inhibitor|Janus kinase (JAK) inhibitor]], for the treatment of severe alopecia areata.<ref name="Lilly PR 20220613">{{cite press release | title=FDA Approves Lilly and Incyte's Olumiant (baricitinib) As First and Only Systemic Medicine for Adults with Severe Alopecia Areata | publisher=Eli Lilly and Company | via=PR Newswire | date=13 June 2022 | url=https://www.prnewswire.com/news-releases/fda-approves-lilly-and-incytes-olumiant-baricitinib-as-first-and-only-systemic-medicine-for-adults-with-severe-alopecia-areata-301567120.html | access-date=13 June 2022 | archive-date=14 June 2022 | archive-url=https://web.archive.org/web/20220614034511/https://www.prnewswire.com/news-releases/fda-approves-lilly-and-incytes-olumiant-baricitinib-as-first-and-only-systemic-medicine-for-adults-with-severe-alopecia-areata-301567120.html | url-status=live }}</ref>

[[Ritlecitinib]] (Litfulo) was approved for medical use in the United States in June 2023.<ref>{{cite press release | title=FDA Approves Pfizer's Litfulo (Ritlecitinib) for Adults and Adolescents With Severe Alopecia Areata | publisher=Pfizer | via=Business Wire | date=23 June 2023 | url=https://www.businesswire.com/news/home/20230623087591/en/FDA-Approves-Pfizer%E2%80%99s-LITFULO%E2%84%A2-Ritlecitinib-for-Adults-and-Adolescents-With-Severe-Alopecia-Areata | access-date=24 June 2023}}</ref>

[[Fecal matter transplant (F.M.T)|Fecal matter transplants]] (FMT) have been shown to reverse AA and support hair growth, with long lasting results, even going as far as growing additional hair on arms and face while grey hairs even regained colour. This supports the idea of a connection between gut microbiota having a part in hair loss.<ref name="Barquero-Orias_2021">{{cite journal | vauthors = Barquero-Orias D, Muñoz Moreno-Arrones O, Vañó-Galván S | title=Alopecia and the Microbiome: A Future Therapeutic Target? | journal=Actas Dermo-Sifiliográficas | edition = English | publisher=Elsevier BV | volume=112 | issue=6 | year=2021 | issn=1578-2190 | doi=10.1016/j.adengl.2021.03.011 | pages=495–502| s2cid=234207277 | doi-access=free }}</ref>

Hair transplantation may be an alternative for patients with chronic local alopecia areata. The fact that the disease is autoimmune and progresses with relapses is one of the biggest question marks before surgery. There have been case reports in the literature since the early 2000s. However, in an article published long-term follow-up; It is reported that the hair transplanted to the eyebrow area falls out again due to the recurrence of the disease.<ref>{{cite journal | vauthors = Civas E, Aksoy B, Ozer F, Eski M | title = Long-term result of hair transplantation for therapy resistant alopecia areata of eyebrows | journal = Indian Journal of Dermatology, Venereology and Leprology | volume = 83 | issue = 5 | pages = 618–619 | date = 2017 | pmid = 28731020 | doi = 10.4103/ijdvl.IJDVL_913_16 | doi-access = free }}</ref> A similar situation was not mentioned in previous studies on this subject. Perhaps the long-term follow-ups of other studies were not sufficient.

[[Deuruxolitinib]] (Leqselvi) was approved for medical use in the United States in July 2024.<ref>{{cite press release | title=U.S. FDA Approves Leqselvi (deuruxolitinib), an Oral JAK Inhibitor for the Treatment of Severe Alopecia Areata | publisher=Sun Pharmaceutical |via=PR Newswire | date=25 July 2024 | url=https://www.prnewswire.com/news-releases/us-fda--approves-leqselvi-deuruxolitinib-an-oral-jak-inhibitor-for-the-treatment-of-severe-alopecia-areata-302207222.html | access-date=26 July 2024}}</ref>

== Prognosis ==

In most cases that begin with a small number of patches of hair loss, hair grows back after a few months to a year.<ref name=aocd/> In cases with a greater number of patches, hair can either grow back or progress to alopecia areata totalis or, in rare cases, alopecia areata universalis.<ref name=aocd/>

No loss of body function occurs, and the effects of alopecia areata are psychological (loss of self-image due to hair loss), although these can be severe. Loss of hair also means the scalp burns more easily in the sun. Patients may also have aberrant nail formation because [[keratin]] forms both hair and nails.{{citation needed|date=August 2020}}

Hair may grow back and then fall out again later. This may not indicate a recurrence of the condition, but rather a natural cycle of growth-and-shedding from a relatively synchronised start; such a pattern will fade over time. Episodes of alopecia areata before puberty predispose to chronic recurrence of the condition.<ref name=merck/>

Alopecia can be the cause of psychological [[stress (medicine)|stress]]. Because hair loss can lead to significant changes in appearance, individuals with it may experience [[social anxiety|social phobia]], [[anxiety]], and [[depression (mood)|depression]].<ref name=HuntMcHale2005>{{cite journal | vauthors = Hunt N, McHale S | title = The psychological impact of alopecia | journal = BMJ | volume = 331 | issue = 7522 | pages = 951–953 | date = October 2005 | pmid = 16239692 | pmc = 1261195 | doi = 10.1136/bmj.331.7522.951 | type = Review }}</ref>

== Epidemiology ==

The condition affects 0.1%–0.2% of the population, with a lifetime risk of 1%-2%,<ref>{{cite journal | vauthors = Safavi KH, Muller SA, Suman VJ, Moshell AN, Melton LJ | title = Incidence of alopecia areata in Olmsted County, Minnesota, 1975 through 1989 | journal = Mayo Clinic Proceedings | volume = 70 | issue = 7 | pages = 628–633 | date = July 1995 | pmid = 7791384 | doi = 10.4065/70.7.628 }}</ref> and is more common in females.<ref name="occurrence">{{cite journal | vauthors = Lundin M, Chawa S, Sachdev A, Bhanusali D, Seiffert-Sinha K, Sinha AA | title = Gender differences in alopecia areata | journal = Journal of Drugs in Dermatology | volume = 13 | issue = 4 | pages = 409–413 | date = April 2014 | pmid = 24719059 }}</ref>

Alopecia areata occurs in people who are otherwise healthy and have no other skin disorders.<ref name=merck>{{MerckManual|10|124|b|983|Alopecia Areata}}</ref> Initial presentation most commonly occurs in the early childhood, late [[teenage]] years, or young adulthood, but can happen at any ages.<ref name=draelos/> Patients also tend to have a slightly higher incidence of conditions related to the immune system, such as [[asthma]], allergies, [[Atopy|atopic]] dermatitis, and [[hypothyroidism]].

=== Ethnic and socioeconomic disparities ===
The prevalence and impact of AA vary across different ethnic groups and socioeconomic backgrounds.<ref name="Thompson 924–935">{{cite journal | vauthors = Thompson AR, Tziotzios C, Nesnas J, Randall R, Czachorowski M, Messenger AG | title = Lifetime incidence and healthcare disparities in alopecia areata: a UK population-based cohort study | journal = The British Journal of Dermatology | volume = 191 | issue = 6 | pages = 924–935 | date = November 2024 | pmid = 39104082 | doi = 10.1093/bjd/ljae307 | doi-access = free }}</ref> Studies indicate that people of [[Asian people|Asian descent]] have the highest risk, with nearly 6 cases per 100 people, compared to fewer than 2 cases per 100 people among White individuals.<ref name="Thompson 924–935"/> People living in urban or economically disadvantaged areas face a higher likelihood of developing AA.<ref name="Thompson 924–935"/> The effects of the condition also differ by ethnicity: individuals of Black descent with AA are more likely to experience [[Anxiety disorder|anxiety]] and require medical leave from work.<ref name="Thompson 924–935"/> These findings suggest that genetic, environmental, and social factors may influence both the likelihood of developing AA and its broader personal and professional impact.<ref name="Thompson 924–935"/>

== Society and culture ==
The term "alopecia", used by physicians dating back to [[Hippocrates]], originates from the [[Greek language|Greek]] word for fox, "alopex", and was so-named due to fur loss seen in fox mange. "Areata" is derived from the [[Latin]] word, "area", meaning a vacant space or patch.<ref>{{cite journal | vauthors = Callander J, Yesudian PD | title = Nosological Nightmare and Etiological Enigma: A History of Alopecia Areata | journal = International Journal of Trichology | volume = 10 | issue = 3 | pages = 140–141 | date = 2018 | pmid = 30034197 | pmc = 6028995 | doi = 10.4103/ijt.ijt_23_18 | doi-access = free }}</ref>

Alopecia areata and alopecia barbae have been identified by some as the biblical {{transliteration|he|nethek}} condition that is part of the greater {{transliteration|he|tzaraath}} family of skin disorders; the said disorders are purported to being discussed in the [[Book of Leviticus]], chapter 13.<ref>{{cite book | title = Alopecia Areata: Jewish Answers to a Modern Disease | vauthors = Rivkin P | pages = 18–33 | isbn = 978-1-5375-2975-2| date = September 2016 | publisher = CreateSpace Independent Publishing Platform }}</ref>

===Notable people===
NASCAR driver [[Joey Logano]], obstacle athlete Kevin Bull,<ref>{{Cite web|title=American alopecia ninja attacks awareness|url=https://www.dermatologytimes.com/view/american-alopecia-ninja-attacks-awareness|access-date=23 February 2021|website=Dermatology Times|date=8 July 2016 |archive-date=27 January 2021|archive-url=https://web.archive.org/web/20210127232304/https://www.dermatologytimes.com/view/american-alopecia-ninja-attacks-awareness|url-status=live}}</ref> politicians [[Peter Dutton]]<ref>{{cite news| vauthors = Maiden S |author-link=Samantha Maiden|date=27 May 2022|title=Peter Dutton officially launches Liberal leadership campaign, reveals skin condition is alopecia|url=https://www.news.com.au/national/politics/peter-dutton-officially-launches-liberal-leadership-campaign/news-story/05fde1957cb005342fd05d11d189fe60|work=[[news.com.au]]|location=|access-date=5 June 2022|archive-date=30 May 2022|archive-url=https://web.archive.org/web/20220530164213/https://www.news.com.au/national/politics/peter-dutton-officially-launches-liberal-leadership-campaign/news-story/05fde1957cb005342fd05d11d189fe60|url-status=live}}</ref> and [[Ayanna Pressley]],<ref>{{Cite web|title=Exclusive: Rep. Ayanna Pressley Reveals Beautiful Bald Head and Discusses Alopecia for the First Time|url=https://theglowup.theroot.com/exclusive-rep-ayanna-pressley-reveals-beautiful-bald-1841039847|access-date=13 January 2021|website=The Glow Up|date=16 January 2020|archive-date=16 January 2020|archive-url=https://web.archive.org/web/20200116163857/https://theglowup.theroot.com/exclusive-rep-ayanna-pressley-reveals-beautiful-bald-1841039847|url-status=live}}</ref> [[K-pop]] singer [[Peniel Shin]] of [[BtoB (band)|BtoB]],<ref>{{cite web |author=Kang Hee-jung |date=15 November 2016 |title="탈모인 파이팅!" 프니엘, '안녕하세요' 출연 후기 게재 |script-title= |trans-title="Fighting hair loss!" Peniel's review of'Hello' appeared |url=https://www.news1.kr/articles/?2831564 |access-date=6 May 2022 |work=News1 |language=Korean |archive-date=17 November 2020 |archive-url=https://web.archive.org/web/20201117061906/https://www.news1.kr/articles/?2831564 |url-status=live }}</ref> actors [[Christopher Reeve]],<ref name="Groopman2003">{{cite magazine | vauthors = Groopman J |title=The Reeve Effect |url=https://www.newyorker.com/magazine/2003/11/10/the-reeve-effect |magazine=The New Yorker |date=2 November 2003}}</ref> [[Anthony Carrigan (actor)|Anthony Carrigan]],<ref>{{Cite news | vauthors = Nedd A, Kibblesmith D, Bertozzi D |date=27 February 2015 |title=Gotham's Anthony Carrigan Talks Acting, Alopecia, And Learning To Love His Look |work=[[BuzzFeed]] |url=https://www.buzzfeed.com/alexisnedd/gothams-anthony-carrigan-talks-acting-alopecia-and-learning |access-date=17 August 2018 |archive-date=25 September 2018 |archive-url=https://web.archive.org/web/20180925220040/https://www.buzzfeed.com/alexisnedd/gothams-anthony-carrigan-talks-acting-alopecia-and-learning |url-status=live }}</ref> [[Greg Grunberg]] and [[Alan Fletcher (actor)|Alan Fletcher]],<ref>{{cite news | vauthors = Knox D |date=20 May 2022 |title=Alan Fletcher reveals alopecia to fans |work=[[TV Tonight]] |location= |url=https://tvtonight.com.au/2022/05/alan-fletcher-reveals-alopecia-to-fans.html |access-date=8 June 2022 |archive-date=8 June 2022 |archive-url=https://web.archive.org/web/20220608021209/https://tvtonight.com.au/2022/05/alan-fletcher-reveals-alopecia-to-fans.html |url-status=live }}</ref> and actresses [[Jada Pinkett Smith]],<ref>{{cite web |title=How Jada Pinkett Smith is uplifting Black women with alopecia | vauthors = Bellamy C |url=https://www.nbcnews.com/news/nbcblk/jada-pinkett-smith-uplifting-black-women-alopecia-rcna11273 |website=NBCBLK |date=7 January 2022 |access-date=28 March 2022 |archive-date=28 March 2022 |archive-url=https://web.archive.org/web/20220328034022/https://www.nbcnews.com/news/nbcblk/jada-pinkett-smith-uplifting-black-women-alopecia-rcna11273 |url-status=live }}</ref> [[May Calamawy]],<ref>{{Cite web| vauthors = Calamawy M |date=11 June 2020|title=Sharing My Alopecia Helped Me Set New Expectations for Myself|url=https://www.glamour.com/story/may-calamawy-sharing-my-alopecia-helped-me-set-new-expectations-for-myself|url-status=live|access-date=5 June 2021|website=[[Glamour (magazine)|Glamour]]|archive-date=5 June 2021|archive-url=https://web.archive.org/web/20210605204913/https://www.glamour.com/story/may-calamawy-sharing-my-alopecia-helped-me-set-new-expectations-for-myself}}</ref> and [[Lili Reinhart]]<ref>{{cite web | url = https://www.hollywoodreporter.com/news/general-news/lili-reinhart-diagnosed-alopecia-1235811063/ | title = Lili Reinhart Reveals She Was Diagnosed With Alopecia | work = Hollywood Reporter }}</ref> all have some form of alopecia areata.

== Research ==

Many medications are being studied.<ref>{{cite web|title=Search - clinicaltrials.gov for alopecia areata|url=https://clinicaltrials.gov/ct2/results?term=alopecia+areata&recr=Open&rslt=&type=&cond=&intr=&titles=&outc=&spons=&lead=&id=&state1=&cntry1=&state2=&cntry2=&state3=&cntry3=&locn=&gndr=&rcv_s=&rcv_e=&lup_s=&lup_e=|website=clinicaltrials.gov|publisher=National Institutes of Health|access-date=5 April 2016|url-status = live|archive-url=https://web.archive.org/web/20170908192255/https://clinicaltrials.gov/ct2/results?term=alopecia+areata&recr=Open&rslt=&type=&cond=&intr=&titles=&outc=&spons=&lead=&id=&state1=&cntry1=&state2=&cntry2=&state3=&cntry3=&locn=&gndr=&rcv_s=&rcv_e=&lup_s=&lup_e=|archive-date=8 September 2017}}</ref>

In 2014, preliminary findings showing that oral [[ruxolitinib]], a drug approved by the US [[Food and Drug Administration]] (FDA) for bone marrow disorder [[myelofibrosis]], restored hair growth in three individuals with long-standing and severe disease.<ref>{{cite journal | title = A ray of hope for alopecia areata patients | vauthors = Mohammadi D | journal = The Pharmaceutical Journal | volume = 296 | issue = 7889 | doi = 10.1211/PJ.2016.20201092 | year = 2016 }}</ref>

In March 2020, the US FDA granted [[breakthrough therapy]] designation to [[baricitinib]] for the systematic treatment of alopecia areata<ref>{{cite press release | title=Lilly Receives FDA Breakthrough Therapy Designation for Baricitinib for the Treatment of Alopecia Areata | publisher=Eli Lilly and Company | via=PR Newswire | date=16 March 2020 | url=https://www.prnewswire.com/news-releases/lilly-receives-fda-breakthrough-therapy-designation-for-baricitinib-for-the-treatment-of-alopecia-areata-301024437.html | access-date=16 March 2020 | archive-date=17 March 2020 | archive-url=https://web.archive.org/web/20200317170907/https://www.prnewswire.com/news-releases/lilly-receives-fda-breakthrough-therapy-designation-for-baricitinib-for-the-treatment-of-alopecia-areata-301024437.html | url-status=live }}</ref> and granted approval in June 2022,<ref name="Lilly PR 20220613" /> with a 32% efficacy rate for people with 50% hair loss reaching 80% scalp coverage in 36 weeks.<ref name="FDA PR 20220613">{{cite press release | title=FDA Approves First Systemic Treatment for Alopecia Areata | website=U.S. [[Food and Drug Administration]] (FDA) | date=13 June 2022 | url=https://www.fda.gov/news-events/press-announcements/fda-approves-first-systemic-treatment-alopecia-areata | access-date=13 June 2022 | archive-date=14 June 2022 | archive-url=https://web.archive.org/web/20220614051142/https://www.fda.gov/news-events/press-announcements/fda-approves-first-systemic-treatment-alopecia-areata | url-status=live }} {{PD-notice}}</ref> It acts as an [[Janus kinase inhibitor|inhibitor of janus kinase]] (JAK), blocking the subtypes [[JAK1]] and [[JAK2]].<ref name="CHMP">{{cite web |title=Summary of opinion for Olumiant |publisher=[[European Medicines Agency]] (EMA) |date=15 December 2016 |url=http://www.ema.europa.eu/docs/en_GB/document_library/Summary_of_opinion_-_Initial_authorisation/human/004085/WC500218183.pdf |access-date=18 December 2016 |archive-date=15 March 2018 |archive-url=https://web.archive.org/web/20180315212105/http://www.ema.europa.eu/docs/en_GB/document_library/Summary_of_opinion_-_Initial_authorisation/human/004085/WC500218183.pdf |url-status=live }}</ref>

== References ==
{{Reflist}}

== External links ==
{{Commons category|Alopecia areata}}

<!-- BEFORE inserting new links here you should first post it to the talk page, otherwise your edit is likely to be reverted -->
* {{DermAtlas|42}}
{{Medical resources
|  ICD10          = {{ICD10|L|63||l|60}}
|  ICD9           = {{ICD9|704.01}}
|  ICDO           =
|  OMIM           = 104000
|  MedlinePlus    = 001450
|  eMedicineSubj  = derm
|  eMedicineTopic = 14
|  DiseasesDB     = 430
|  MeshID         = D000506
}}
{{Human hair}}
{{Diseases of the skin and appendages by morphology}}
{{Disorders of skin appendages}}
{{Portal bar | Medicine}}
{{Authority control}}

{{DEFAULTSORT:Alopecia Areata}}
[[Category:Autoimmune diseases]]
[[Category:Conditions of the skin appendages]]
[[Category:Human hair]]
[[Category:Hair diseases]]
[[Category:Wikipedia medicine articles ready to translate]]
[[Category:Wikipedia neurology articles ready to translate]]