Hair loss

Last updated

Hair loss
Other namesAlopecia, baldness
Alopecia.jpg
A bald spot on a man
Pronunciation
Specialty Dermatology
Symptoms Loss of hair from part of the head or body. [2]
Complications Psychological distress [3]
Types Male-pattern hair loss, female-pattern hair loss, alopecia areata, telogen effluvium [4]
TreatmentAccepting the condition, medications, shaving of balding areas, surgery [4]
Medication Pattern hair loss: minoxidil, finasteride [5]
Alopecia areata: steroid injections [4]
Frequency50% of males, 25% of females (pattern hair loss by age 50) [4] [6]

Hair loss, also known as alopecia or baldness, refers to a loss of hair from part of the head or body. [2] Typically at least the head is involved. [4] The severity of hair loss can vary from a small area to the entire body. [7] Inflammation or scarring is not usually present. [4] Hair loss in some people causes psychological distress. [3]

Contents

Common types include male- or female-pattern hair loss, alopecia areata, and a thinning of hair known as telogen effluvium. [4] The cause of male-pattern hair loss is a combination of genetics and male hormones; the cause of female pattern hair loss is unclear; the cause of alopecia areata is autoimmune; and the cause of telogen effluvium is typically a physically or psychologically stressful event. [4] Telogen effluvium is very common following pregnancy. [4]

Less common causes of hair loss without inflammation or scarring include the pulling out of hair, certain medications including chemotherapy, HIV/AIDS, hypothyroidism, and malnutrition including iron deficiency. [3] [4] Causes of hair loss that occurs with scarring or inflammation include fungal infection, lupus erythematosus, radiation therapy, and sarcoidosis. [3] [4] Diagnosis of hair loss is partly based on the areas affected. [4]

Treatment of pattern hair loss may simply involve accepting the condition, which can also include shaving one's head. [4] Interventions that can be tried include the medications minoxidil (or finasteride) and hair transplant surgery. [5] [6] Alopecia areata may be treated by steroid injections in the affected area, but these need to be frequently repeated to be effective. [4] Hair loss is a common problem. [4] Pattern hair loss by age 50 affects about half of men and a quarter of women. [4] About 2% of people develop alopecia areata at some point in time. [4]

Terminology

Baldness is the partial or complete lack of hair growth, and part of the wider topic of "hair thinning". The degree and pattern of baldness varies, but its most common cause is androgenic hair loss, alopecia androgenetica, or alopecia seborrheica, with the last term primarily used in Europe.[ citation needed ]

Hypotrichosis

Hypotrichosis is a condition of abnormal hair patterns, predominantly loss or reduction. It occurs, most frequently, by the growth of vellus hair in areas of the body that normally produce terminal hair. Typically, the individual's hair growth is normal after birth, but shortly thereafter the hair is shed and replaced with sparse, abnormal hair growth. The new hair is typically fine, short and brittle, and may lack pigmentation. Baldness may be present by the time the subject is 25 years old. [8]

Signs and symptoms

A case of mid-frontal baldness: Andre Agassi Andre Agassi (2011).jpg
A case of mid-frontal baldness: Andre Agassi

Symptoms of hair loss include hair loss in patches usually in circular patterns, dandruff, skin lesions, and scarring. Alopecia areata (mild – medium level) usually shows in unusual hair loss areas, e.g., eyebrows, backside of the head or above the ears, areas the male pattern baldness usually does not affect. In male-pattern hair loss, loss and thinning begin at the temples and the crown and hair either thins out or falls out. Female-pattern hair loss occurs at the frontal and parietal.

People have between 100,000 and 150,000 hairs on their head. The number of strands normally lost in a day varies but on average is 100. [9] In order to maintain a normal volume, hair must be replaced at the same rate at which it is lost. The first signs of hair thinning that people will often notice are more hairs than usual left in the hairbrush after brushing or in the basin after shampooing. Styling can also reveal areas of thinning, such as a wider parting or a thinning crown.[ citation needed ]

Throughout his political career, Urho Kekkonen, the President of Finland, was well known for his baldness. He was last known to have had hair in about the 1920s. This photo is of Kekkonen in 1959. Uudenvuodenpuhe 1959.jpg
Throughout his political career, Urho Kekkonen, the President of Finland, was well known for his baldness. He was last known to have had hair in about the 1920s. This photo is of Kekkonen in 1959.

Skin conditions

A substantially blemished face, back and limbs could point to cystic acne. The most severe form of the condition, cystic acne, arises from the same hormonal imbalances that cause hair loss and is associated with dihydrotestosterone production. [11]

Psychological

The psychology of hair thinning is a complex issue. Hair is considered an essential part of overall identity: especially for women, for whom it often represents femininity and attractiveness. Men typically associate a full head of hair with youth and vigor. People experiencing hair thinning often find themselves in a situation where their physical appearance is at odds with their own self-image and commonly worry that they appear older than they are or less attractive to others. Psychological problems due to baldness, if present, are typically most severe at the onset of symptoms. [12]

Hair loss induced by cancer chemotherapy has been reported to cause changes in self-concept and body image. Body image does not return to the previous state after regrowth of hair for a majority of patients. In such cases, patients have difficulties expressing their feelings (alexithymia) and may be more prone to avoiding family conflicts. Family therapy can help families to cope with these psychological problems if they arise. [13]

Causes

Although not completely understood,[ citation needed ] hair loss can have many causes:

Pattern hair loss

Male pattern hair loss is believed to be due to a combination of genetics and the male hormone dihydrotestosterone. [4] The cause in female pattern hair loss remains unclear. [4]

Infection

Drugs

Trauma

Pregnancy

Hair loss often follows childbirth in the postpartum period without causing baldness. During pregnancy, the hair is thicker owing to increased circulating estrogens. Approximately three months after giving birth (typically between 2 and 5 months), estrogen levels drop and hair loss occurs, often particularly noticeably around the hairline and temple area. Hair typically grows back normally and treatment is not indicated. [21] [22] A similar situation occurs in women taking the fertility-stimulating drug clomiphene.

Other causes

Other causes of hair loss include:

Genetics

Genetic forms of localized autosomal recessive hypotrichosis include:

Type OMIM GeneLocus
LAH1 607903 DSG4 18q12
LAH2 604379 LIPH 3q27
LAH3 611452 P2RY5 13q14.12-q14.2

Pathophysiology

Hair follicle growth occurs in cycles. Each cycle consists of a long growing phase (anagen), a short transitional phase (catagen) and a short resting phase (telogen). At the end of the resting phase, the hair falls out (exogen) and a new hair starts growing in the follicle, beginning the cycle again.

Normally, about 40 (0–78 in men) hairs reach the end of their resting phase each day and fall out. [28] When more than 100 hairs fall out per day, clinical hair loss (telogen effluvium) may occur.[ citation needed ] A disruption of the growing phase causes abnormal loss of anagen hairs (anagen effluvium).

Diagnosis

Because they are not usually associated with an increased loss rate, male-pattern and female-pattern hair loss do not generally require testing. If hair loss occurs in a young man with no family history, drug use could be the cause.

There are two types of identification tests for female pattern baldness: the Ludwig Scale and the Savin Scale. Both track the progress of diffused thinning, which typically begins on the crown of the head behind the hairline, and becomes gradually more pronounced. For male pattern baldness, the Hamilton–Norwood scale tracks the progress of a receding hairline and/or a thinning crown, through to a horseshoe-shaped ring of hair around the head and on to total baldness.[ citation needed ]

In almost all cases of thinning, and especially in cases of severe hair loss, it is recommended to seek advice from a doctor or dermatologist. Many types of thinning have an underlying genetic or health-related cause, which a qualified professional will be able to diagnose.[ citation needed ]

Management

Hiding hair loss

General Douglas MacArthur with a comb over Syngman Rhee and Douglas MacArthur.jpg
General Douglas MacArthur with a comb over

One method of hiding hair loss is the comb over, which involves restyling the remaining hair to cover the balding area. It is usually a temporary solution, useful only while the area of hair loss is small. As the hair loss increases, a comb over becomes less effective.

Another method is to wear a hat or a hairpiece such as a wig or toupee. The wig is a layer of artificial or natural hair made to resemble a typical hair style. In most cases the hair is artificial. Wigs vary widely in quality and cost. In the United States, the best wigs –those that look like real hair –cost up to tens of thousands of dollars. Organizations also collect individuals' donations of their own natural hair to be made into wigs for young cancer patients who have lost their hair due to chemotherapy or other cancer treatment in addition to any type of hair loss.

Eyebrows

Though not as common as the loss of hair on the head, chemotherapy, hormone imbalance, forms of hair loss, and other factors can also cause loss of hair in the eyebrows. Loss of growth in the outer one third of the eyebrow is often associated with hypothyroidism. Artificial eyebrows are available to replace missing eyebrows or to cover patchy eyebrows. Eyebrow embroidery is another option which involves the use of a blade to add pigment to the eyebrows. This gives a natural 3D look for those who are worried about an artificial look and it lasts for two years. Micropigmentation (permanent makeup tattooing) is also available for those who want the look to be permanent.

Medications

Portuguese advertisement for a hair-loss product from the 1940s Petroleo Quimico Nally - Ilustracao Portugueza (6Set1941).png
Portuguese advertisement for a hair-loss product from the 1940s

Treatments for the various forms of hair loss have limited success. Three medications have evidence to support their use in male pattern hair loss: minoxidil, finasteride, and dutasteride. [31] [32] They typically work better to prevent further hair loss, than to regrow lost hair. [31] On June 13, 2022, the U.S. Food and Drug Administration (FDA) approved Olumiant (baricitinib) for adults with severe alopecia areatal. It is the first FDA approved drug for systemic treatment, or treatment for any area of the body. [33]

Surgery

Hair transplantation is usually carried out under local anesthetic. A surgeon will move healthy hair from the back and sides of the head to areas of thinning. The procedure can take between four and eight hours, and additional sessions can be carried out to make hair even thicker. Transplanted hair falls out within a few weeks, but regrows permanently within months. [37]

Chemotherapy

Hypothermia caps may be used to prevent hair loss during some kinds of chemotherapy, specifically, when taxanes or anthracyclines are administered. [38] It is not recommended to be used when cancer is present in the skin of the scalp or for lymphoma or leukemia. [39] There are generally only minor side effects from scalp cooling given during chemotherapy. [40]

Embracing baldness

Instead of attempting to conceal their hair loss, some people embrace it by either doing nothing about it or sporting a shaved head. [41] [42] The general public became more accepting of men with shaved heads in the early 1950s, when Russian-American actor Yul Brynner began sporting the look; the resulting phenomenon inspired many of his male fans to shave their heads. [43] Male celebrities then continued to bring mainstream popularity to shaved heads, [44] [45] [46] including athletes such as Michael Jordan [47] and Zinedine Zidane and actors such as Dwayne Johnson, [48] Ben Kingsley, [49] and Jason Statham. [50] Female baldness is still viewed as less normal in various parts of the world. [51] [52]

Alternative medicine

Dietary supplements are not typically recommended. [32] There is only one small trial of saw palmetto which shows tentative benefit in those with mild to moderate androgenetic alopecia. [32] There is no evidence for biotin. [32] Evidence for most other alternative medicine remedies is also insufficient. [53] There was no good evidence for ginkgo, aloe vera, ginseng, bergamot, hibiscus, or sophora as of 2011. [53]

Many people use unproven treatments to treat hair loss. [31] Egg oil, in Indian, [54] Japanese, Unani (Roghan Baiza Murgh) [55] and Chinese [56] traditional medicine, was traditionally used as a treatment for hair loss.[ medical citation needed ]

Research

Research is looking into connections between hair loss and other health issues. While there has been speculation about a connection between early-onset male pattern hair loss and heart disease, a review of articles from 1954 to 1999 found no conclusive connection between baldness and coronary artery disease. The dermatologists who conducted the review suggested further study was needed. [57]

Environmental factors are under review. A 2007 study indicated that smoking may be a factor associated with age-related hair loss among Asian men. The study controlled for age and family history, and found statistically significant positive associations between moderate or severe male pattern hair loss and smoking status. [58]

Vertex baldness is associated with an increased risk of coronary heart disease (CHD) and the relationship depends upon the severity of baldness, while frontal baldness is not. Thus, vertex baldness might be a marker of CHD and is more closely associated with atherosclerosis than frontal baldness. [28]

Hair follicle aging

A key aspect of hair loss with age is the aging of the hair follicle. [59] Ordinarily, hair follicle renewal is maintained by the stem cells associated with each follicle. Aging of the hair follicle appears to be primed by a sustained cellular response to the DNA damage that accumulates in renewing stem cells during aging. [60] This damage response involves the proteolysis of type XVII collagen by neutrophil elastase in response to DNA damage in hair follicle stem cells. Proteolysis of collagen leads to elimination of the damaged cells and, consequently, to terminal hair follicle miniaturization.

Hedgehog signaling

In June 2022 the University of California, Irvine announced that researchers have discovered that hedgehog signaling in murine fibroblasts induces new hair growth and hair multiplication while hedgehog activation increases fibroblast heterogeneity and drives new cell states. [61] A new signaling molecule called SCUBE3 potently stimulates hair growth and may offer a therapeutic treatment for androgenetic alopecia. [62]

Etymology

The term alopecia ( /ˌæləˈpiːʃiə/ ) is from the Classical Greek ἀλώπηξ, alōpēx, meaning "fox". The origin of this usage is because this animal sheds its coat twice a year, or because in ancient Greece foxes often lost hair because of mange.

See also

Related Research Articles

<span class="mw-page-title-main">Alopecia areata</span> Medical condition

Alopecia areata, also known as spot baldness, is a condition in which hair is lost from some or all areas of the body. It often results in a few bald spots on the scalp, each about the size of a coin. 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. People are generally otherwise healthy. In a few cases, all the hair on the scalp is lost, or all body hair is lost. Hair loss can be permanent, or temporary.

<span class="mw-page-title-main">Minoxidil</span> Medication used to treat hair loss

Minoxidil is a medication used for the treatment of high blood pressure and pattern hair loss. It is an antihypertensive and a vasodilator. It is available as a generic medication by prescription in oral tablet form and over the counter as a topical liquid or foam.

<span class="mw-page-title-main">Hair follicle</span> Organ found in mammalian skin

The hair follicle is an organ found in mammalian skin. It resides in the dermal layer of the skin and is made up of 20 different cell types, each with distinct functions. The hair follicle regulates hair growth via a complex interaction between hormones, neuropeptides, and immune cells. This complex interaction induces the hair follicle to produce different types of hair as seen on different parts of the body. For example, terminal hairs grow on the scalp and lanugo hairs are seen covering the bodies of fetuses in the uterus and in some newborn babies. The process of hair growth occurs in distinct sequential stages: anagen is the active growth phase, catagen is the regression of the hair follicle phase, telogen is the resting stage, exogen is the active shedding of hair phase and kenogen is the phase between the empty hair follicle and the growth of new hair.

<span class="mw-page-title-main">Telogen effluvium</span> Medical condition

Telogen effluvium is a scalp disorder characterized by the thinning or shedding of hair resulting from the early entry of hair in the telogen phase. It is in this phase that telogen hairs begin to shed at an increased rate, where normally the approximate rate of hair loss is 125 hairs per day.

The management of hair loss, includes prevention and treatment of alopecia, baldness, and hair thinning, and regrowth of hair.

Trichology is the study of the hair and scalp. The term derives from Ancient Greek θρίξ (thríx), "hair" and -λογία -logia. In most jurisdictions the title of a trichologist, not the field of trichology, is considered a para-medical discipline.

<span class="mw-page-title-main">Hair transplantation</span> Surgical operation to relocate hair follicles

Hair transplantation is a surgical technique that removes hair follicles from one part of the body, called the 'donor site', to a bald or balding part of the body known as the 'recipient site'. The technique is primarily used to treat male pattern baldness. In this minimally invasive procedure, grafts containing hair follicles that are genetically resistant to balding are transplanted to the bald scalp.

<span class="mw-page-title-main">Pattern hair loss</span> Medical condition

Pattern hair loss is a hair loss condition that primarily affects the top and front of the scalp. In male-pattern hair loss (MPHL), the hair loss typically presents itself as either a receding front hairline, loss of hair on the crown and vertex of the scalp, or a combination of both. Female-pattern hair loss (FPHL) typically presents as a diffuse thinning of the hair across the entire scalp.

Madarosis is a condition that results in the loss of eyelashes, and sometimes eyebrows. The term "madarosis" is derived from the ancient Greek "madaros", meaning "bald". It originally was a disease of only losing eyelashes but it currently is the loss of both eyelashes and eyebrows. Eyebrows and eyelashes are both important in the prevention of bacteria and other foreign objects from entering the eye. A majority of patients with madarosis have leprosy, and it was reported that 76% of patients with varying types of leprosy had madarosis.

Anagen effluvium is the pathologic loss of anagen or growth-phase hairs. Classically, it is caused by radiation therapy to the head and systemic chemotherapy, especially with alkylating agents.

<span class="mw-page-title-main">Loose anagen syndrome</span> Medical condition

Loose anagen syndrome, also known as loose anagen hair syndrome, is a hair disorder related to dermatology. It is characterised by the easy and pain free detachment of anagen staged hairs from the scalp. This hair condition can be spontaneous or genetically inherited.

Scarring hair loss, also known as cicatricial alopecia, is the loss of hair which is accompanied with scarring. This is in contrast to non scarring hair loss.

Non scarring hair loss, also known as noncicatricial alopecia is the loss of hair without any scarring being present. There is typically little inflammation and irritation, but hair loss is significant. This is in contrast to scarring hair loss during which hair follicles are replaced with scar tissue as a result of inflammation. Hair loss may be spread throughout the scalp (diffuse) or at certain spots (focal). The loss may be sudden or gradual with accompanying stress.

<span class="mw-page-title-main">Trichoscopy</span> Medical diagnostic method

Trichoscopy is a method of hair and scalp evaluation and is used for diagnosing hair and scalp diseases. The method is based on dermoscopy. In trichoscopy hair and scalp structures may be visualized at many-fold magnification. Currently magnifications ranging from 10-fold to 70-fold are most popular in research and clinical practice.

<span class="mw-page-title-main">Frontal fibrosing alopecia</span> Medical condition

Frontal fibrosing alopecia is the frontotemporal hairline recession and eyebrow loss in postmenopausal women that is associated with perifollicular erythema, especially along the hairline. It is considered to be a clinical variant of lichen planopilaris.

The growth of human hair occurs everywhere on the body except for the soles of the feet, the palms of the hands, the inside of the mouth, the lips, the backs of the ears, some external genital areas, the navel, and, apart from eyelashes, the eyelids. Hair is a stratified squamous keratinized epithelium made of multi-layered flat cells whose rope-like filaments provide structure and strength to the hair shaft. The protein called keratin makes up hair and stimulates hair growth. Hair follows a specific growth cycle with three distinct and concurrent phases: anagen, catagen, and telogen. Each phase has specific characteristics that determine the length of the hair.

Short anagen syndrome is a condition where hair does not grow beyond a short length, due to an unusually short duration of active hair growth. Most cases are associated with fine blond hair.

Scalp reduction is a surgical procedure in which the hairless region of the scalp of a bald person is reduced. This procedure can reduce the area of the scalp in which hair transplantation is needed or even eliminate the need for hair transplantation.

Frictional alopecia is the loss of hair that is caused by rubbing of the hair, follicles, or skin around the follicle. The most typical example of this is the loss of ankle hair among people who wear socks constantly for years. The hair may not grow back even years after the source of friction has ended.

Angela M. Christiano is a molecular geneticist in the field of dermatology. Her research focuses on genes involved in hair and skin growth, as well as treatments for hair loss and skin cancers. She is the Richard and Mildred Rhodebeck Professor of Dermatology and Professor of Genetics and Development at Columbia University Vagelos College of Physicians and Surgeons.

References

  1. ↑ "alopecia". Dictionary.com Unabridged (Online). n.d.
  2. 1 2 "Hair loss". NHS Choices. Archived from the original on 27 September 2013. Retrieved 22 September 2013.
  3. 1 2 3 4 Nalluri, R; Harries, M (February 2016). "Alopecia in general medicine". Clinical Medicine. 16 (1): 74–78. doi:10.7861/clinmedicine.16-1-74. PMC   4954340 . PMID   26833522.
  4. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 Vary JC, Jr (November 2015). "Selected Disorders of Skin Appendages – Acne, Alopecia, Hyperhidrosis". The Medical Clinics of North America. 99 (6): 1195–1211. doi:10.1016/j.mcna.2015.07.003. PMID   26476248.
  5. 1 2 McElwee, Kevin J.; Shapiro, Jerry (June 2012). "Promising therapies for treating and/or preventing androgenic alopecia". Skin Therapy Letter. 17 (6): 1–4. PMID   22735503.
  6. 1 2 Leavitt, M. (2008). "Understanding and Management of Female Pattern Alopecia". Facial Plastic Surgery. 24 (4): 414–427. doi:10.1055/s-0028-1102905. PMID   19034818. S2CID   260136951.
  7. ↑ "Hair loss". DermNet. Archived from the original on 2016-06-25. Retrieved 2016-08-03.
  8. ↑ Dawber, Rodney P. R.; Van Neste, Dominique (2004). Hair and scalp disorders: common presenting signs, differential diagnosis and treatment (2nd ed.). Informa Health Care. pp. 53–54. ISBN   978-1-84184-193-9.
  9. ↑ Hair growth at eMedicine
  10. ↑ Kuvat: Kekkonen ei ollut aina kalju – tältä tuleva presidentti näytti teini-ikäisenä (in Finnish)
  11. ↑ Bergler-Czop, Beata; Brzezińska-Wcisło, Ligia (May 2004). "Czynniki hormonalne w etiologii tradziku pospolitego" [Hormonal factors in etiology of common acne]. Polski Merkuriusz Lekarski (in Polish). 16 (95): 490–492. PMID   15518435.
  12. ↑ Passchier, Jan; Erdman, Jeroen; Hammiche, Fatima; Erdman, Ruud A. M. (September 2016). "Androgenetic Alopecia: Stress of Discovery". Psychological Reports. 98 (1): 226–228. doi:10.2466/PR0.98.1.226-228. PMID   16673981. S2CID   11586141.
  13. ↑ Poot, F (September 2004). "Le retentissement psychologique des pathologies chroniques du cheveu" [Psychological consequences of chronic hair diseases]. Revue Médicale de Bruxelles (in French). 25 (4): A286–288. PMID   15516058. Archived from the original on 2020-06-26. Retrieved 2020-06-23.
  14. ↑ "Infectious hair disease – syphilis". Keratin.com. Archived from the original on 2011-09-28. Retrieved 2011-11-17.
  15. 1 2 "Drug-Induced Hair Loss". WebMD.
  16. ↑ "Drug Induced Hair Loss". American Hair Loss Association. Archived from the original on 2020-08-01. Retrieved 2020-06-23.
  17. ↑ Pappas, Peter G.; Kauffman, CA; Perfect, J; Johnson, PC; McKinsey, DS; Bamberger, DM; Hamill, R; Sharkey, PK; Chapman, SW; Sobel, JD (1 September 1995). "Alopecia Associated with Fluconazole Therapy". Annals of Internal Medicine. 123 (5): 354–357. doi:10.7326/0003-4819-123-5-199509010-00006. PMID   7625624. S2CID   53091175.
  18. ↑ "Alopecia". Healthgrades. 26 June 2014.
  19. ↑ Nnoruka, Nkechi Edith (October 2005). "Hair loss: is there a relationship with hair care practices in Nigeria?". International Journal of Dermatology. 44 (s1): 13–17. doi:10.1111/j.1365-4632.2005.02801.x. PMID   16187950. S2CID   26608122.
  20. ↑ "Causes of Hair Loss". American Hair Loss Association.
  21. ↑ Schiff, Bencel L.; Kern, A B (1 May 1963). "Study of Postpartum Alopecia". Archives of Dermatology. 87 (5): 609–611. doi:10.1001/archderm.1963.01590170067011. PMID   13991677.
  22. ↑ Eastham, John H (February 2001). "Postpartum Alopecia". The Annals of Pharmacotherapy. 35 (2): 255–258. doi:10.1345/1542-6270(2001)035<0255:pa>2.0.co;2. PMID   11215848.
  23. ↑ James, William; Berger, Timothy; Elston, Dirk (2005). Andrews' Diseases of the Skin: Clinical Dermatology. (10th ed.). Saunders. ISBN   0-7216-2921-0.
  24. ↑ Alopecia Areata Archived 2008-10-13 at the Wayback Machine , by Maria G. Essig, MS, ELS, Yahoo! Health
  25. ↑ "Congenital triangular alopecia". Archived from the original on 2011-07-13. Retrieved 2010-06-29.
  26. ↑ Morinaga, Hironobu; Mohri, Yasuaki; Grachtchouk, Marina; Asakawa, Kyosuke; Matsumura, Hiroyuki; Oshima, Motohiko; Takayama, Naoya; Kato, Tomoki; Nishimori, Yuriko; Sorimachi, Yuriko; Takubo, Keiyo (July 2021). "Obesity accelerates hair thinning by stem cell-centric converging mechanisms". Nature. 595 (7866): 266–271. Bibcode:2021Natur.595..266M. doi:10.1038/s41586-021-03624-x. ISSN   1476-4687. PMC   9600322 . PMID   34163066. S2CID   235625692.
  27. ↑ "What is Alopecia: What Causes Alopecia?". MedicalBug. 6 February 2012. Archived from the original on 22 January 2013. Retrieved 28 March 2012.
  28. 1 2 Yamada, T; Hara, K; Umematsu, H; Kadowaki, T (2013). "Male pattern baldness and its association with coronary heart disease: A meta-analysis". BMJ Open . 3 (4): e002537. doi:10.1136/bmjopen-2012-002537. PMC   3641488 . PMID   23554099. Open Access logo PLoS transparent.svg
  29. ↑ "The hair pull test". Keratin.com. Archived from the original on 22 January 2013. Retrieved 28 March 2012.[ self-published source? ]
  30. ↑ Rudnicka L, Olszewska M, Rakowska A, Kowalska-Oledzka E, Slowinska M (2008). "Trichoscopy: a new method for diagnosing hair loss". J Drugs Dermatol. 7 (7): 651–654. PMID   18664157.
  31. 1 2 3 Banka, N; Bunagan, MJ; Shapiro, J (January 2013). "Pattern hair loss in men: diagnosis and medical treatment". Dermatologic Clinics. 31 (1): 129–40. doi:10.1016/j.det.2012.08.003. PMID   23159182.
  32. 1 2 3 4 5 6 Rogers, Nicole E.; Avram, Marc R. (October 2008). "Medical treatments for male and female pattern hair loss". Journal of the American Academy of Dermatology. 59 (4): 547–566. doi:10.1016/j.jaad.2008.07.001. PMID   18793935.
  33. ↑ "FDA Approves First Systemic Treatment for Alopecia Areata | FDA". Fda.gov. 2022-06-13. Retrieved 2022-06-29.
  34. ↑ "An Old Medicine Remedies Hair Loss for Pennies a Day, Doctors Say - The New York Times". The New York Times . 2022-08-22. Archived from the original on 2022-08-22. Retrieved 2022-08-22.
  35. ↑ Joly, Pascal (October 2006). "The use of methotrexate alone or in combination with low doses of oral corticosteroids in the treatment of alopecia totalis or universalis". Journal of the American Academy of Dermatology. 55 (4): 632–636. doi:10.1016/j.jaad.2005.09.010. PMID   17010743.
  36. ↑ Shapiro, Jerry (December 2013). "Current Treatment of Alopecia Areata". Journal of Investigative Dermatology Symposium Proceedings. 16 (1): S42 –S44. doi: 10.1038/jidsymp.2013.14 . PMID   24326551.
  37. ↑ 'Hair Transplants', WebMD: "Hair Transplant Procedures: Average Cost, What to Expect, and More". Archived from the original on 2013-09-21. Retrieved 2013-09-21.
  38. ↑ Grevelman, E.G.; Breed, W.P.M. (March 2005). "Prevention of chemotherapy-induced hair loss by scalp cooling". Annals of Oncology. 16 (3): 352–358. doi: 10.1093/annonc/mdi088 . PMID   15642703.
  39. ↑ Breed, Wim P. M. (1 January 2004). "What is wrong with the 30-year-old practice of scalp cooling for the prevention of chemotherapy-induced hair loss?". Supportive Care in Cancer. 12 (1): 3–5. doi:10.1007/s00520-003-0551-8. PMID   14615930. S2CID   25031894.
  40. ↑ Komen, Manon M.C.; Smorenburg, Carolien H.; van den Hurk, Corina J.G.; Nortier, J.W.R. (Hans) (2011). "Hoofdhuidkoeling tegen alopecia door chemotherapie" [Scalp cooling for chemotherapy-induced alopecia](PDF). Nederlands Tijdschrift voor Geneeskunde (in Dutch). 155 (45): A3768. PMID   22085565.
  41. ↑ Benedictus, Leo (February 2, 2013). "The 10 rules for bald men". The Guardian. ISSN   0261-3077 . Retrieved December 1, 2018.
  42. ↑ Rockwell, Taylor (October 16, 2015). "The 20 Greatest Bald Heads in the History of Soccer". pastemagazine.com. Archived from the original on December 15, 2018. Retrieved December 1, 2018.
  43. ↑ Brynner, Rock (2006). Empire & odyssey: the Brynners in Far East Russia and beyond. Steerforth Press.
  44. ↑ Crouse, Richard (2005). Reel Winners: Movie Award Trivia . Dundurn. p.  171.
  45. ↑ Doyle, Hubert (2008). Ventures with the World of Celebrities, Movies & TV. Joshua Tree. ISBN   9780976867760.
  46. ↑ Douty, Linda (2011). How Did I Get to Be 70 When I'm 35 Inside?: Spiritual Surprises of Later Life. SkyLight Paths. ISBN   9781594732973.
  47. ↑ Gaines, Cork (17 April 2020). "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". Business Insider.
  48. ↑ Bryant, Kenzie (3 April 2017). "Dwayne 'The Rock' Johnson Explains Why He's Bald". Vanity Fair.
  49. ↑ Steele, Francesca (19 April 2014). "Ferdinand Kingsley interview: 'Yeah, but mum's dad was totally bald too!'". Spectator. Retrieved 8 June 2020.
  50. ↑ Huynh, Mike (24 July 2019). "Jason Statham Is Showing Bald Men How To Look Stylishly Masculine". DMARGE. Retrieved 9 June 2020.
  51. ↑ "Cultural Perceptions of Hair & Baldness". The Trichological Society.[ self-published source? ]
  52. ↑ Ramos, Paulo Müller; Miot, Hélio Amante (2015). "Female Pattern Hair Loss: a clinical and pathophysiological review". Anais Brasileiros de Dermatologia. 90 (4): 529–543. doi:10.1590/abd1806-4841.20153370. PMC   4560543 . PMID   26375223.
  53. 1 2 Blumeyer, A; Tosti, A; Messenger, A; Reygagne, P; Del Marmol, V; Spuls, PI; Trakatelli, M; Finner, A; Kiesewetter, F; Trüeb, R; Rzany, B; Blume-Peytavi, U; European Dermatology Forum, (EDF) (October 2011). "Evidence-based (S3) guideline for the treatment of androgenetic alopecia in women and in men". Journal of the German Society of Dermatology. 9 (Suppl 6): S1–57. doi:10.1111/j.1610-0379.2011.07802.x. PMID   21980982. S2CID   29821046.
  54. ↑ Panda, H. (2004). Handbook On Ayurvedic Medicines With Formulae, Processes And Their Uses. NIIR Project Consultancy Services. p. 146. ISBN   978-81-86623-63-3.
  55. ↑ Babu, S. Suresh (2005). Home Made Herbal Cosmetics. Pustak Mahal. p. 103. ISBN   978-81-223-0775-7.
  56. ↑ Zhou, Zhongying; Jin, Hui De (1997). Clinical Manual of Chinese Herbal Medicine and Acupuncture. Churchill Livingstone. p. 222. ISBN   978-0-443-05128-9.
  57. ↑ Rebora, Alfredo (1 July 2001). "Baldness and Coronary Artery Disease: The Dermatologic Point of View of a Controversial Issue". Archives of Dermatology. 137 (7): 943–947. PMID   11453815.
  58. ↑ Su, Lin-Hui; Chen, Tony Hsiu-Hsi (1 November 2007). "Association of Androgenetic Alopecia With Smoking and Its Prevalence Among Asian Men". Archives of Dermatology. 143 (11): 1401–1406. doi: 10.1001/archderm.143.11.1401 . PMID   18025364.
  59. ↑ Lei M, Chuong CM (2016). "STEM CELLS. Aging, alopecia, and stem cells". Science. 351 (6273): 559–560. Bibcode:2016Sci...351..559L. doi: 10.1126/science.aaf1635 . PMID   26912687.
  60. ↑ Matsumura H, Mohri Y, Binh NT, Morinaga H, Fukuda M, Ito M, Kurata S, Hoeijmakers J, Nishimura EK (2016). "Hair follicle aging is driven by transepidermal elimination of stem cells via COL17A1 proteolysis". Science. 351 (6273): aad4395. doi:10.1126/science.aad4395. PMID   26912707. S2CID   5078019.
  61. ↑ Liu, Yingzi (30 June 2022). "Hedgehog signaling reprograms hair follicle niche fibroblasts to a hyper-activated state". Developmental Cell. 57 (14): 1758–1775.e7. doi:10.1016/j.devcel.2022.06.005. PMC   9344965 . PMID   35777353. S2CID   250203913.
  62. ↑ Liu, Yingzi (1 July 2022). "Team discovers signaling molecule that potently stimulates hair growth". Phys.org.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.