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| ==[[Alopecia overview|Overview]]== | | ==[[Alopecia overview|Overview]]== |
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| Alopecia is defined as loss of hair regardless of the cause. It can occur anywhere on the body. The hair cycle consists of three phases: '''anagen phase''', which is the growth phase, '''catagen phase''', which is the resting phase, and '''telogen phase''', which is the shedding phase. This is the phase where hair falls out. <ref name="pmid30520225">{{cite journal| author=Monib KME, Hussein MS, Kandeel WS| title=The relation between androgenetic thin hair diagnosed by trichoscope and benign prostatic hyperplasia. | journal=J Cosmet Dermatol | year= 2018 | volume= | issue= | pages= | pmid=30520225 | doi=10.1111/jocd.12835 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=30520225 }} </ref>
| | ==[[Alopecia historical perspective|Historical Perspective]]== |
| Ninety percent of hair are in the anagen phase and the remaining ten percent are in the catagen and telogen phases. <ref name="pmid30520145">{{cite journal| author=Gordon SC, Abudu M, Zancanaro P, Ko JM, Rosmarin D| title=Rebound effect associated with JAK inhibitor use in the treatment of alopecia areata. | journal=J Eur Acad Dermatol Venereol | year= 2019 | volume= 33 | issue= 4 | pages= e156-e157 | pmid=30520145 | doi=10.1111/jdv.15383 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=30520145 }} </ref> In the telogen phase, hair is going to recycle, and it starts growing again in the anagen phase. <ref name="pmid30519542">Spaich S, Kinder J, Hetjens S, Fuxius S, Gerhardt A, Sütterlin M (2018) [https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=30519542 Patient Preferences Regarding Chemotherapy in Metastatic Breast Cancer-A Conjoint Analysis for Common Taxanes.] ''Front Oncol'' 8 ():535. [http://dx.doi.org/10.3389/fonc.2018.00535 DOI:10.3389/fonc.2018.00535] PMID: [https://pubmed.gov/30519542 30519542]</ref>
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| Alopecia can be subdivided into two main categories: scarring and non-scarring.
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| The most common type is '''non-scarring or androgenetic alopecia'''. The majority of men start to lose hair in the third decade of life, while women begin to lose their hair in the fifth or sixth decade of life. As an individual ages, they will lose hair. Men more often lose hair in the front and the temporal regions of the scalp, while women tend to lose hair from the central area of the scalp. Also, female hair loss rarely results in complete baldness while male hair loss can end up with complete baldness. Males tend to retain hair at the posterior area of the scalp because the hair in this region is more resistant to the effects of androgenic hormones. <ref name="pmid30506608">{{cite journal| author=Li J, Kong XB, Chen XY, Zhong WZ, Chen JY, Liu Y | display-authors=etal| title=Protective role of α2-macroglobulin against jaw osteoradionecrosis in a preclinical rat model. | journal=J Oral Pathol Med | year= 2019 | volume= 48 | issue= 2 | pages= 166-173 | pmid=30506608 | doi=10.1111/jop.12809 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=30506608 }} </ref>
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| ==[[Alopecia classification|Classification]]== | | ==[[Alopecia classification|Classification]]== |
| '''The six major categories of non-scarring alopecia are''':
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| * '''Alopecia areata''': this can affect any part of the body. When it affects only a portion of an area of the body, it is called alopecia areata. When it affects the entire site, it is called alopecia totalis. When it involves the whole body, it is called alopecia universalis. The etiology is unknown, but it might be related to an autoimmune disease.<ref name="pmid30502419">{{cite journal| author=Lee YB, Jun M, Lee WS| title=Alopecia areata and poliosis: A retrospective analysis of 258 cases. | journal=J Am Acad Dermatol | year= 2019 | volume= 80 | issue= 6 | pages= 1776-1778 | pmid=30502419 | doi=10.1016/j.jaad.2018.11.033 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=30502419 }} </ref>
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| * '''Androgenetic alopecia''': is a pattern of hair loss that is affected by the hormones and genes.
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| * '''Telogen effluvium''': results from shifting of hair growth cycle from the anagen phase towards the telogen phase. It may result from an illness like hypothyroidism or hyperthyroidism. Also, it can arise from stress like major surgery or severe psychological stress <ref name="pmid26833522">Nalluri R, Harries M (2016) [https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=26833522 Alopecia in general medicine.] ''Clin Med (Lond)'' 16 (1):74-8. [http://dx.doi.org/10.7861/clinmedicine.16-1-74 DOI:10.7861/clinmedicine.16-1-74] PMID: [https://pubmed.gov/26833522 26833522]</ref>. Other causes include drugs, crash diet, poor feeding. <ref name="pmid30502414">Liu LY, King BA (2019) [https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=30502414 Response to tofacitinib therapy of eyebrows and eyelashes in alopecia areata.] ''J Am Acad Dermatol'' 80 (6):1778-1779. [http://dx.doi.org/10.1016/j.jaad.2018.11.037 DOI:10.1016/j.jaad.2018.11.037] PMID: [https://pubmed.gov/30502414 30502414]</ref>
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| * '''Traumatic alopecia''': This results from forceful traction of the hair. It is commonly seen in children and is similar to traction alopecia. Also, trichotillomania is a type of traumatic alopecia in which the patient pulls on his/her hair repeatedly. <ref name="pmid30501438">{{cite journal| author=Chen P, Chen F, Zhou B| title=The risk of dermatological toxicities of combined BRAF and MEK inhibition versus BRAF inhibition alone in melanoma patients: a systematic review and meta-analysis. | journal=Cutan Ocul Toxicol | year= 2019 | volume= 38 | issue= 2 | pages= 105-111 | pmid=30501438 | doi=10.1080/15569527.2018.1553180 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=30501438 }} </ref>
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| * '''Tinea capitis''': the classical kind of tinea capitis (black-dots) causes non-scarring hair loss, unlike other types like kerion and favus.
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| * '''Anagen effluvium''': This is hair shedding that occurs during the anagen phase of the cell cycle. Seen in cancer patients who are receiving chemotherapeutic agents.
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| '''Scarring alopecia is divided into three major types''':
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| * Tinea capitis: This is the inflammatory variety of tinea capitis (favus) or kerion, which is when the fungi causes abscess formation, may culminate with scarring alopecia.
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| * Alopecia mucinosa: This occurs when mucinous material accumulates in the hair follicles and the sebaceous glands. The mucinous material causes an inflammatory response that hinders the growth of hair.
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| * Alopecia neoplastica: This occurs when there is metastatic infiltration of the scalp hair with malignant cells.
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| Other causes of hair loss that occurs with scarring or inflammation include systemic lupus erythematosus, radiation therapy, and sarcoidosis.<ref name="pmid26833522">{{cite journal| author=Nalluri R, Harries M| title=Alopecia in general medicine. | journal=Clin Med (Lond) | year= 2016 | volume= 16 | issue= 1 | pages= 74-8 | pmid=26833522 | doi=10.7861/clinmedicine.16-1-74 | pmc=4954340 | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=26833522 }} </ref> <ref name="pmid26476248">Vary JC (2015) [https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=26476248 Selected Disorders of Skin Appendages--Acne, Alopecia, Hyperhidrosis.] ''Med Clin North Am'' 99 (6):1195-211. [http://dx.doi.org/10.1016/j.mcna.2015.07.003 DOI:10.1016/j.mcna.2015.07.003] PMID: [https://pubmed.gov/26476248 26476248]</ref> Diagnosis of hair loss is partly based on the areas affected. <ref name="pmid26476248">Vary JC (2015) [https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=26476248 Selected Disorders of Skin Appendages--Acne, Alopecia, Hyperhidrosis.] ''Med Clin North Am'' 99 (6):1195-211. [http://dx.doi.org/10.1016/j.mcna.2015.07.003 DOI:10.1016/j.mcna.2015.07.003] PMID: [https://pubmed.gov/26476248 26476248]</ref>
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| ==[[Alopecia pathophysiology|Pathophysiology]]== | | ==[[Alopecia pathophysiology|Pathophysiology]]== |
| The pathophysiology of alopecia is dependent on the type of alopecia. In the case of alopecia areata, the exact pathophysiology is currently unknown, however, the prevailing hypothesis is that it is as a result of T-cell–mediated autoimmunity. In androgenetic alopecia, both hormonal and genetic factors play a role in the pathogenesis. In telogen effluvium, the hair loss may influenced by hormones or stress, or other unknown factors. <ref name="pmid30511001">Yu L, Lu Z (2018) [https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=30511001 Linear alopecia areata.] ''JAAD Case Rep'' 4 (10):1072-1073. [http://dx.doi.org/10.1016/j.jdcr.2018.08.015 DOI:10.1016/j.jdcr.2018.08.015] PMID: [https://pubmed.gov/30511001 30511001]</ref> The dermatophyte infection is responsible for hair loss in tinea capitis. In anagen effluvium, the shedding of hair is under the effect of chemotherapeutic agents. In alopecia mucinosa, the infiltration of the scalp with abnormal lymphocytes is the cause. <ref name="pmid30501016">{{cite journal| author=Davey L, Clarke V, Jenkinson E| title=Living with alopecia areata: an online qualitative survey study. | journal=Br J Dermatol | year= 2019 | volume= 180 | issue= 6 | pages= 1377-1389 | pmid=30501016 | doi=10.1111/bjd.17463 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=30501016 }} </ref>
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| ==Histopathology==
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| In androgenetic alopecia, there are miniaturized hair follicles with an increase in the telogen-to-anagen ratio without inflammatory reaction. In anagen effluvium, there is a decrease in anagen hair without any inflammatory response. Finally, in alopecia mucinosa, there is an infiltrate of the epidermis, dermis, and peribulbar lymphocytic infiltrate mainly anaplastic cells. In patients with alopecia areata, there is a peribulbar lymphocytic infiltrate with a decrease in the ratio of anagen to telogen hair. Telogen effluvium is characterized by an increase in the number of catagen hair. In tinea capitis, there is evidence of fungal infection as under a microscope along with a neutrophilic infiltrate.
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| ==[[Alopecia causes|Causes]]== | | ==[[Alopecia causes|Causes]]== |
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| '''Pattern hair loss'''
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| A combination of genetics and the male hormone dihydrotestosterone (DHT) is believed to be the cause of male pattern hair loss. <ref name="pmid26476248">Vary JC (2015) [https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=26476248 Selected Disorders of Skin Appendages--Acne, Alopecia, Hyperhidrosis.] ''Med Clin North Am'' 99 (6):1195-211. [http://dx.doi.org/10.1016/j.mcna.2015.07.003 DOI:10.1016/j.mcna.2015.07.003] PMID: [https://pubmed.gov/26476248 26476248]</ref> The cause of female pattern hair loss is currently unknown. <ref name="pmid26476248">Vary JC (2015) [https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=26476248 Selected Disorders of Skin Appendages--Acne, Alopecia, Hyperhidrosis.] ''Med Clin North Am'' 99 (6):1195-211. [http://dx.doi.org/10.1016/j.mcna.2015.07.003 DOI:10.1016/j.mcna.2015.07.003] PMID: [https://pubmed.gov/26476248 26476248]</ref>
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| '''Infection'''
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| * Fungal infections (such as tinea capitis)
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| * Folliculitis
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| * Dissecting cellulitis
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| * Secondary syphilis: it has a moth-eaten appearance. <ref name="pmid22761476">Qiao J, Fang H (2013) [https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=22761476 Moth-eaten alopecia: a sign of secondary syphilis.] ''CMAJ'' 185 (1):61. [http://dx.doi.org/10.1503/cmaj.120229 DOI:10.1503/cmaj.120229] PMID: [https://pubmed.gov/22761476 22761476]</ref>
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| * Demodex folliculorum, a microscopic mite that feeds on the sebum produced by the sebaceous glands, denies hair essential nutrients and can cause thinning. Demodex folliculorum is not present on every scalp and is more likely to live in an excessively oily scalp environment.
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| '''Drugs'''
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| * Temporary or permanent hair loss can be caused by several medications, including chemotherapeutic medications, anti-mycotics <ref name="pmid7625624">{{cite journal| author=Pappas PG, Kauffman CA, Perfect J, Johnson PC, McKinsey DS, Bamberger DM | display-authors=etal| title=Alopecia associated with fluconazole therapy. | journal=Ann Intern Med | year= 1995 | volume= 123 | issue= 5 | pages= 354-7 | pmid=7625624 | doi=10.7326/0003-4819-123-5-199509010-00006 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=7625624 }} </ref>, antihypertensives, cholesterol-lowering agents, as well as medications for heart disease and diabetes. Also, medications such as hormone replacement therapy, contraceptives, steroids and acne medications can cause hair loss.
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| '''Trauma'''
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| * Traction alopecia is most commonly seen in people with hairstyles that involve pulling hair with force. Also, rough brushing, heat styling and rough scalp massage can damage the cuticle, the hard outer layer of the hair. This weakens hair and leads to hair loss.
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| * Frictional alopecia is hair loss caused by rubbing of the hair or follicles, most often around the ankles due to socks and is often permanent.
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| * Trichotillomania is the loss of hair caused by compulsive pulling and bending of the hairs. Onset of this disorder tends to begin around the onset of puberty and usually continues through adulthood. Due to the constant extraction of the hair roots, permanent hair loss can occur.
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| * Traumas such as childbirth, major surgery, poisoning, and severe stress may cause a hair loss condition known as telogen effluvium, <ref name="pmid16187950">Nnoruka EN, Nnoruka NE (2005) [https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=16187950 Hair loss: is there a relationship with hair care practices in Nigeria?] ''Int J Dermatol'' 44 Suppl 1 ():13-7. [http://dx.doi.org/10.1111/j.1365-4632.2005.02801.x DOI:10.1111/j.1365-4632.2005.02801.x] PMID: [https://pubmed.gov/16187950 16187950]</ref> in which a large number of hairs enter the resting phase at the same time, causing shedding and subsequent thinning. The condition also presents as a side effect of chemotherapy – while targeting dividing cancer cells, this treatment also affects hair's growth phase with the result that almost 90% of hairs fall out soon after chemotherapy starts.
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| * Radiation to the scalp, as when radiotherapy is applied to the head for the treatment of certain cancers there, can cause baldness of the irradiated areas.
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| '''Pregnancy'''
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| Hair loss can occur in the postpartum period. It usually does not lead to baldness. This is be due to a drop in estrogen levels. This affects hair follicles, leading to hair loss, mostly around the hairline and temple area. It is often transient and treatment is not indicated. <ref name="pmid13991677">SCHIFF BL, KERN AB (1963) [https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=13991677 Study of postpartum alopecia.] ''Arch Dermatol'' 87 ():609-11. [http://dx.doi.org/10.1001/archderm.1963.01590170067011 DOI:10.1001/archderm.1963.01590170067011] PMID: [https://pubmed.gov/13991677 13991677]</ref> <ref name="pmid11215848">Eastham JH (2001) [https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=11215848 Postpartum alopecia.] ''Ann Pharmacother'' 35 (2):255-8. [http://dx.doi.org/10.1345/aph.10153 DOI:10.1345/aph.10153] PMID: [https://pubmed.gov/11215848 11215848]</ref> A similar situation occurs in women taking the fertility-stimulating drug clomiphene.
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| '''Other causes'''
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| Alopecia areata is an autoimmune disorder in which there is spot hair loss. It can range from just one location as seen in alopecia areata monolocularis, to hair loss on the entire body (Alopecia areata universalis).
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| Localized or diffuse hair loss may also occur in cicatricial alopecia. Tumors and skin outgrowths also induce localized baldness.
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| Hypothyroidism and the side effects of its related medications can cause hair loss, typically frontal, which is particularly associated with thinning of the outer third of the eyebrows. Hyperthyroidism can also cause hair loss, which is parietal rather than frontal. Hyperparathyroidism can also cause hair loss. <ref name="pmid23960405">Vincent M, Yogiraj K (2013) [https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=23960405 A Descriptive Study of Alopecia Patterns and their Relation to Thyroid Dysfunction.] ''Int J Trichology'' 5 (1):57-60. [http://dx.doi.org/10.4103/0974-7753.114701 DOI:10.4103/0974-7753.114701] PMID: [https://pubmed.gov/23960405 23960405]</ref>
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| Temporary loss of hair can occur in areas where sebaceous cysts are present for considerable duration (normally one to several weeks).
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| Congenital triangular alopecia – It is a triangular, or oval in some cases, shaped patch of hair loss in the temple area of the scalp that occurs mostly in young children. The affected area mainly contains vellus hair follicles or no hair follicles at all, but it does not expand. Its causes are unknown, and although it is a permanent condition, it does not have any other effect on the affected individuals. <ref name="pmid26180448">Yin Li VC, Yesudian PD (2015) [https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=26180448 Congenital Triangular Alopecia.] ''Int J Trichology'' 7 (2):48-53. [http://dx.doi.org/10.4103/0974-7753.160089 DOI:10.4103/0974-7753.160089] PMID: [https://pubmed.gov/26180448 26180448]</ref>
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| Gradual thinning of hair with age is a natural condition known as involutional alopecia. This is caused by an increasing number of hair follicles switching from the growth, or anagen, phase into a resting phase, or telogen phase, so that remaining hairs become shorter and fewer in number.
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| Other causes of hair loss include:
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| * Diabetes
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| * Lupus erythematosus
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| * Tufted folliculitis
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| * Alopecia mucinosa
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| * Biotinidase deficiency
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| * Pseudopelade of Brocq
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| ==[[Alopecia differential diagnosis|Differentiating Alopecia from other Diseases]]== | | ==[[Alopecia differential diagnosis|Differentiating Alopecia from other Diseases]]== |
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| '''Non-scarring Alopecia'''
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| * Hyperthyroidism
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| * Hypothyroidism
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| * Syphilis
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| * Hypoparathyroidism
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| * Androgenetic alopecia
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| * Alopecia areata
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| * Telogen effluvium
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| * Traction alopecia
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| * Trichotillomania
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| * Anagen effluvium
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| '''Scarring Alopecia'''
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| * Alopecia mucinosa
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| * Metastatic infiltrate
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| * Favus
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| * Kerion
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| In general, the distribution and pattern the hair loss, presence of co-morbidities, presence of infections, and mechanical factors are helpful in differentiating the different types of alopecia
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| ==[[Alopecia epidemiology and demographics|Epidemiology and Demographics]]== | | ==[[Alopecia epidemiology and demographics|Epidemiology and Demographics]]== |
| * Androgenetic alopecia affects 50% of men and 15% of women, particularly postmenopausal women. <ref name="pmid30513014">{{cite journal| author=Rinaldi F, Marzani B, Pinto D, Sorbellini E| title=Randomized controlled trial on a PRP-like cosmetic, biomimetic peptides based, for the treatment of alopecia areata. | journal=J Dermatolog Treat | year= 2019 | volume= 30 | issue= 6 | pages= 588-593 | pmid=30513014 | doi=10.1080/09546634.2018.1544405 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=30513014 }} </ref>
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| * In alopecia areata, the prevalence is 0.2% and has no age or sexual predilection. However, it affects white races more than dark races.
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| * In telogen effluvium, women are at higher predisposition than men.
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| * Tinea capitis has a higher incidence among the pediatric age group and in darker races. <ref name="pmid30511475">Owczarczyk-Saczonek A, Wygonowska E, Budkiewicz M, Placek W (2019) [https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=30511475 Serum sickness disease in a patient with alopecia areata and Meniere' disease after PRP procedure.] ''Dermatol Ther'' 32 (2):e12798. [http://dx.doi.org/10.1111/dth.12798 DOI:10.1111/dth.12798] PMID: [https://pubmed.gov/30511475 30511475]</ref>
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| * Anagen effluvium is more common in cancer patients receiving treatment with chemotherapeutic agents.
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| ==[[Alopecia risk factors|Risk Factors]]== | | ==[[Alopecia risk factors|Risk Factors]]== |
| Risk factors include:
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| * Poor hygiene
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| * Poor diet
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| * Physiological and psychological stress
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| * Chronic disease
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| * Mechanical stressors such as tight braids
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| * Hormonal imbalance
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| * Medications
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| * Male sex
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| * Autoimmune diseases
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| * Family history
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| * Chemicals and hair care products
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| ==[[Alopecia natural history, complications and prognosis|Natural History, Complications and Prognosis]]== | | ==[[Alopecia natural history, complications and prognosis|Natural History, Complications and Prognosis]]== |
| The term alopecia (/ˌæləˈpiːʃiə/) comes from alōpēx, meaning "fox" in Greek. This usage originated either from the fox shedding its coat twice a year, or because in ancient Greece foxes often lost hair because of mange. Patients with alopecia are at increased risk of psychosocial complications of hair loss such as anxiety and depression. At the same time, these patients need to be assessed for other autoimmune conditions such as thyroid conditions, vitiligo, etc. People with alopecia areata may at increased risk of developing insulin resistance. <ref name="pmid31089876">Shahidi-Dadras M, Bahraini N, Rajabi F, Younespour S (2019) [https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=31089876 Patients with alopecia areata show signs of insulin resistance.] ''Arch Dermatol Res'' 311 (7):529-533. [http://dx.doi.org/10.1007/s00403-019-01929-6 DOI:10.1007/s00403-019-01929-6] PMID: [https://pubmed.gov/31089876 31089876]</ref>
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| Research has shown that about 8.5% of patients with alopecia totalis and universalis achieved a total recovery. Many of the patients will obtain at least a transient recovery of partial or total hair regrowth. Response to treatment is often unpredictable, and healthcare providers should be aware of the prognosis and its effects to properly counsel patients. <ref name="pmid31593606">Burroway B, Griggs J, Tosti A (2020) [https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=31593606 Alopecia totalis and universalis long-term outcomes: a review.] ''J Eur Acad Dermatol Venereol'' 34 (4):709-715. [http://dx.doi.org/10.1111/jdv.15994 DOI:10.1111/jdv.15994] PMID: [https://pubmed.gov/31593606 31593606]</ref>
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| The Alopecia Areata Predictive Score is a trichoscopy-based assessment used to predict the treatment outcome in patients with patchy alopecia areata. <ref name="pmid31301100">Waśkiel-Burnat A, Rakowska A, Sikora M, Olszewska M, Rudnicka L (2020) [https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=31301100 Alopecia areata predictive score: A new trichoscopy-based tool to predict treatment outcome in patients with patchy alopecia areata.] ''J Cosmet Dermatol'' 19 (3):746-751. [http://dx.doi.org/10.1111/jocd.13064 DOI:10.1111/jocd.13064] PMID: [https://pubmed.gov/31301100 31301100]</ref>
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| ==Diagnosis== | | ==Diagnosis== |
| [[Alopecia diagnostic study of choice|Diagnostic study of choice]] | [[Alopecia history and symptoms|History and Symptoms]] | [[Alopecia physical examination|Physical Examination]] | [[Alopecia laboratory findings|Laboratory Findings]] | [[Alopecia electrocardiogram|Electrocardiogram]] | [[Alopecia x ray|X-Ray Findings]] | [[Alopecia echocardiography and ultrasound|Echocardiography and Ultrasound]] | [[Alopecia CT scan|CT-Scan Findings]] | [[Alopecia MRI|MRI Findings]] | [[Alopecia other imaging findings|Other Imaging Findings]] | [[Alopecia other diagnostic studies|Other Diagnostic Studies]] | | [[Alopecia diagnostic study of choice|Diagnostic study of choice]] | [[Alopecia history and symptoms|History and Symptoms]] | [[Alopecia physical examination|Physical Examination]] | [[Alopecia laboratory findings|Laboratory Findings]] | [[Alopecia electrocardiogram|Electrocardiogram]] | [[Alopecia x ray|X-Ray Findings]] | [[Alopecia echocardiography and ultrasound|Echocardiography and Ultrasound]] | [[Alopecia CT scan|CT-Scan Findings]] | [[Alopecia MRI|MRI Findings]] | [[Alopecia other imaging findings|Other Imaging Findings]] | [[Alopecia other diagnostic studies|Other Diagnostic Studies]] |
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| '''History and Physical Examination'''
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| The quantity, timing, and onset of hair loss can be important clues in narrowing down a diagnosis. It may happen overnight or over a span of months or years. Also, the clinician should inquire about the presence of stressors, co-morbidities, family history, use of bathing and hair care products, hygiene, diet, and overall health.
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| Physical examination may also uncover important indicators of the cause of hair loss. Characteristics such as the pattern of hair loss as in androgenetic alopecia in which male patients tend to lose hair from the frontal and temporal area and female patients tend to lose hair at the central scalp area, or classic alopecia areata in which patients may lose hair from a single area or the face and scalp, as seen in alopecia totalis. In tinea capitis, the classic presentation is black dots associated with broken hair, while favus correlates with the scarring type of alopecia. Telogen effluvium classically presents with diffuse thinning of hair, and a positive pull test. In a patient with alopecia mucinosa, the patient would have multiple flesh-colored papules and nodules infiltrating the skin of the scalp.
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| '''Hair Pull Test'''
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| Test for excessive shedding, it is not diagnostic of a particular hair loss but indicates active hair loss is occurring. Hair should not be washed 24-48 hour prior to a hair pull test. It is performed by gently grasping 40-60 hairs and gently pull upward from different parts of the scalp.
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| A positive test is when three to six or more strands are pulled out.
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| The pull test is positive in:
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| * androgenetic alopecia
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| * alopecia areata and scarring alopecia
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| * telogen effluvium
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| * anagen effluvium
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| * loose anagen syndrome
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| Evaluation of the pulled hair may uncover vital information. For example, if the bulb of the hair is dark, it indicates that the hair is in the anagen phase or if it is white, it indicates that the hair is in the telogen phase.
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| '''Trichoscopy'''
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| This is a noninvasive method of examining hair and scalp. The test may be performed with the use of a dermoscope or a video dermoscope. <ref name="pmid18664157">{{cite journal| author=Rudnicka L, Olszewska M, Rakowska A, Kowalska-Oledzka E, Slowinska M| title=Trichoscopy: a new method for diagnosing hair loss. | journal=J Drugs Dermatol | year= 2008 | volume= 7 | issue= 7 | pages= 651-4 | pmid=18664157 | doi= | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=18664157 }} </ref> The Alopecia Areata Predictive Score makes use of it to predict the treatment outcome in patients with patchy alopecia areata. <ref name="pmid31301100">Waśkiel-Burnat A, Rakowska A, Sikora M, Olszewska M, Rudnicka L (2020) [https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=31301100 Alopecia areata predictive score: A new trichoscopy-based tool to predict treatment outcome in patients with patchy alopecia areata.] ''J Cosmet Dermatol'' 19 (3):746-751. [http://dx.doi.org/10.1111/jocd.13064 DOI:10.1111/jocd.13064] PMID: [https://pubmed.gov/31301100 31301100]</ref>
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| '''Biopsy'''
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| A biopsy will reveal the most information regarding hair loss.
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| '''Laboratory Tests'''
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| Autoantibodies, thyroid function test, ovarian hormones, free testosterone and total testosterone, luteinizing hormone, follicular stimulating hormone, complete blood count and iron panel may be useful in diagnosis.
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| '''Imaging Studies'''
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| Chest X-ray and MRI is used in mycosis fungoides staging. This is useful in the case of alopecia mucinosa.
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| '''Microbiology Testing'''
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| Potasium hydroxide preparation and fungal culture can be used in the diagnosis of tinea capitis. Woods light can also be used to check for signs of fungal infection.
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| ==Treatment== | | ==Treatment== |
| [[Alopecia medical therapy|Medical Therapy]] | [[Alopecia surgery|Surgery]] | [[Alopecia primary prevention|Primary Prevention]] | [[Alopecia secondary prevention|Secondary Prevention]] | [[Alopecia cost-effectiveness of therapy|Cost-Effectiveness of Therapy]] | [[Alopecia future or investigational therapies|Future or Investigational Therapies]] | | [[Alopecia medical therapy|Medical Therapy]] | [[Alopecia surgery|Surgery]] | [[Alopecia primary prevention|Primary Prevention]] | [[Alopecia secondary prevention|Secondary Prevention]] | [[Alopecia cost-effectiveness of therapy|Cost-Effectiveness of Therapy]] | [[Alopecia future or investigational therapies|Future or Investigational Therapies]] |
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| '''Concealment'''
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| Concealment, either by hats, caps, wigs, toupee, or make up, is often used when use of medications or surgery is not desired, feasible, or useful.
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| '''Medications'''
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| There are three medications that have been proven to be efficacious in the treatment of male pattern alopecia. They are minoxidil, finasteride, and dutasteride. <ref name="pmid23159182">Banka N, Bunagan MJ, Shapiro J (2013) [https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=23159182 Pattern hair loss in men: diagnosis and medical treatment.] ''Dermatol Clin'' 31 (1):129-40. [http://dx.doi.org/10.1016/j.det.2012.08.003 DOI:10.1016/j.det.2012.08.003] PMID: [https://pubmed.gov/23159182 23159182]</ref> <ref name="pmid18793935">{{cite journal| author=Rogers NE, Avram MR| title=Medical treatments for male and female pattern hair loss. | journal=J Am Acad Dermatol | year= 2008 | volume= 59 | issue= 4 | pages= 547-66; quiz 567-8 | pmid=18793935 | doi=10.1016/j.jaad.2008.07.001 | pmc= | url=https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=18793935 }} </ref> They mainly act by stopping the progression of hair loss rather than reversing alopecia. <ref name="pmid23159182">Banka N, Bunagan MJ, Shapiro J (2013) [https://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&retmode=ref&cmd=prlinks&id=23159182 Pattern hair loss in men: diagnosis and medical treatment.] ''Dermatol Clin'' 31 (1):129-40. [http://dx.doi.org/10.1016/j.det.2012.08.003 DOI:10.1016/j.det.2012.08.003] PMID: [https://pubmed.gov/23159182 23159182]</ref>
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| * Minoxidil is an over-the-counter topical medication approved for male pattern baldness and alopecia areata. However, the longer the hair has stopped growing, the less likely minoxidil will regrow hair. Regrowth can take as much as 6 months to begin and it is ineffective for the treatment of other causes of hair loss. If the treatment is stopped, any regrown hair and any hair at risk of being lost will be lost. Side effects include are mild scalp irritation, and unwanted hair in other parts of the body. <ref name=Roger2008>{{cite journal |last1=Rogers |first1=Nicole E. |last2=Avram |first2=Marc R. |title=Medical treatments for male and female pattern hair loss |journal=Journal of the American Academy of Dermatology |date=October 2008 |volume=59 |issue=4 |pages=547–566 |doi=10.1016/j.jaad.2008.07.001 |pmid=18793935 }}</ref>
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| * Finasteride is used in male-pattern hair loss and is taken as a pill. It is not indicated for women including pregnant women. Regrowth can begin within 6 weeks of treatment. Finasteride causes an increase in hair retention, the weight of hair, and some increase in regrowth. Side effects are seen about 2% of males and include erectile dysfunction, ejaculatory dysfunction and decreased libido. Treatment should be continued as long as positive results occur. Once treatment is stopped, hair loss resumes.<ref name=Roger2008 />
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| * Corticosteroid injections into the scalp can be used in treatment of alopecia areata and it is done monthly. Oral corticosteroids may be used for extensive hair loss due to alopecia areata.
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| * Immunosuppressants applied to the scalp have been shown to temporarily reverse alopecia areata. However, their side effects make their use questionable. <ref>{{cite journal |last1=Joly |first1=Pascal |title=The use of methotrexate alone or in combination with low doses of oral corticosteroids in the treatment of alopecia totalis or universalis |journal=Journal of the American Academy of Dermatology |date=October 2006 |volume=55 |issue=4 |pages=632–636 |doi=10.1016/j.jaad.2005.09.010 |pmid=17010743 }}</ref>
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| * There is some tentative evidence that anthralin may be useful for treating alopecia areata.<ref>{{cite journal |last1=Shapiro |first1=Jerry |title=Current Treatment of Alopecia Areata |journal=Journal of Investigative Dermatology Symposium Proceedings |date=December 2013 |volume=16 |issue=1 |pages=S42–S44 |doi=10.1038/jidsymp.2013.14 |pmid=24326551 }}</ref>
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| * Hormonal modulators ([[oral contraceptive pill|oral contraceptives]] or antiandrogens such as [[spironolactone]] and [[flutamide]]) can be used for female-pattern hair loss associated with [[hyperandrogenism|hyperandrogenemia]].{{fact|date=June 2020}}
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| '''Surgery'''
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| Hair transplantation involves transplantation of healthy hair taken from the back and sides of the head to the affected areas. The procedure can take between four and eight hours. Additional sessions can be performed to make hair thicker. Transplanted hair falls out within a few weeks, but regrows permanently within months.
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| * Other surgical options, such as follicle transplants, scalp flaps, and hair loss reduction, are available. However, they are expensive and painful, carry a a risk of infection and scarring. Once surgery has occurred, six to eight months are needed before the quality of new hair can be assessed.
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| ** Scalp reduction is the process is the decreasing of the area of bald skin on the head. In time, the skin on the head becomes flexible and stretched enough that some of it can be surgically removed. After the hairless scalp is removed, the space is closed with hair-covered scalp. Scalp reduction is generally done in combination with hair transplantation to provide a natural-looking hairline, especially those with extensive hair loss.
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| ** Hairline lowering can sometimes be used to lower a high hairline secondary to hair loss, although there may be a visible scar after further hair loss.
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| ''' Chemotherapy'''
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| Hypothermia caps may help to prevent hair loss during some kinds of chemotherapy, specifically when tazanes or anthracyclines are used.<ref>{{cite journal |last1=Grevelman |first1=E.G. |last2=Breed |first2=W.P.M. |title=Prevention of chemotherapy-induced hair loss by scalp cooling |journal=Annals of Oncology |date=March 2005 |volume=16 |issue=3 |pages=352–358 |doi=10.1093/annonc/mdi088 |pmid=15642703 |doi-access=free}}</ref> It should not be used when cancer has metastasized to the skin of the scalp or for lymphoma or leukemia.<ref>{{cite journal |last1=Breed |first1=Wim P. M. |title=What is wrong with the 30-year-old practice of scalp cooling for the prevention of chemotherapy-induced hair loss? |journal=Supportive Care in Cancer |date=1 January 2004 |volume=12 |issue=1 |pages=3–5 |doi=10.1007/s00520-003-0551-8 |pmid=14615930 }}</ref> There are generally only minor side effects from treatment.<ref>{{cite journal |last1=Komen |first1=Manon M.C. |last2=Smorenburg |first2=Carolien H. |last3=van den Hurk |first3=Corina J.G. |last4=Nortier |first4=J.W.R. (Hans) |title=Hoofdhuidkoeling tegen alopecia door chemotherapie |trans-title=Scalp cooling for chemotherapy-induced alopecia |language=Dutch |journal=Nederlands tijdschrift voor geneeskunde |date=2011 |volume=155 |issue=45 |pages=A3768 |pmid=22085565 |url=https://www.ntvg.nl/system/files/publications/a3768.pdf }}</ref>
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| '''Acceptance'''
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| Some people, including celebrities, choose to accept their hair loss or completely shave their heads. Examples of celebrities who are bald include Michael Jordan, <ref>{{cite news |last1=Gaines |first1=Cork |title=Michael Jordan once turned down a huge endorsement deal because he didn't like the product's name and another one because he was going bald |url=https://www.businessinsider.com/michael-jordan-beanee-weenee-endorsement-deal-rejected-2019-3 |work=Business Insider |date=17 April 2020 }}</ref> Zinedine Zidane, <ref>{{cite web |author1=Will |title=The Bald Icons: Who is Zinedine Zidane? |url=https://thebaldbrothers.com/the-bald-icons-who-is-zinedine-zidane/ |website=The Bald Brothers |accessdate=9 June 2020 |date=5 March 2020}}{{self-published inline|date=June 2020}}</ref> Dwayne Johnson,<ref>{{cite news |last1=Bryant |first1=Kenzie |title=Dwayne 'The Rock' Johnson Explains Why He’s Bald |url=https://www.vanityfair.com/style/2017/04/dwayne-the-rock-johnson-bald |work=Vanity Fair |date=3 April 2017 }}</ref> Ben Kingsley,<ref>{{cite web |last1=Steele |first1=Francesca |title=Ferdinand Kingsley interview: ‘Yeah, but mum’s dad was totally bald too!’ |url=https://www.spectator.co.uk/article/ferdinand-kingsley-interview-yeah-but-mum-s-dad-was-totally-bald-too- |website=Spectator |accessdate=8 June 2020 |date=19 April 2014}}</ref> and Jason Statham.<ref>{{cite web |last1=Huynh |first1=Mike |title=Jason Statham Is Showing Bald Men How To Look Stylishly Masculine |url=https://www.dmarge.com/2019/07/jason-statham-suit.html |website=DMARGE |accessdate=9 June 2020 |date=24 July 2019}}</ref>
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| == Acknowledgements == | | == Acknowledgements == |
