Hair loss

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Alopecia
Classification and external resources
Alopecia.jpg
Hair loss in a 33-year-old man.
ICD-10L65.9
ICD-9704.09
DiseasesDB14765
MedlinePlus003246
Patient UKHair loss
MeSHD000505
 
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"Bald" redirects here. For other uses, see Bald (disambiguation).
Alopecia
Classification and external resources
Alopecia.jpg
Hair loss in a 33-year-old man.
ICD-10L65.9
ICD-9704.09
DiseasesDB14765
MedlinePlus003246
Patient UKHair loss
MeSHD000505

Hair loss[1] or baldness (technically known as alopecia[2]) is a loss of hair from the head or body. Baldness can refer to general hair loss or androgenic alopecia (male pattern baldness). Some types of baldness can be caused by alopecia areata, an autoimmune disorder. The extreme forms of alopecia areata are alopecia totalis, which involves the loss of all head hair, and alopecia universalis, which involves the loss of all hair from the head and the body.

Baldness and hypotrichosis can have many causes, including fungal infection (tinea capitis), traumatic damage, such as by compulsive pulling (trichotillomania), as a result of radiotherapy or chemotherapy, and as a result of nutritional deficiencies such as iron, and as a result of autoimmune phenomena, including alopecia areata and hair loss associated with systemic lupus erythematosus.[3]

Terminology[edit]

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 alopecia, alopecia androgenetica, or alopecia seborrheica, with the last term primarily used in Europe.[citation needed]

Signs and symptoms[edit]

A case of mid-frontal baldness: Andre Agassi

Symptoms of alopecia 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 where usually the male pattern baldness does not effect. In male-pattern hair loss, loss and thinning begin at the temples and the crown and either thins out or falls out. Female-pattern hair loss occurs at the frontal and parietal.

Excessive daily hair loss[edit]

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.[4] 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.

Skin conditions[edit]

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 DHT production.[5] Seborrheic dermatitis, a condition in which an excessive amount of sebum is produced and builds up on the scalp (looking like an adult cradle cap) is also a symptom of hormonal imbalances, as is an excessively oily or dry scalp. Both can cause hair thinning.

Psychological[edit]

Hair thinning and baldness cause psychological stress due to its effect on appearance. Although societal interest in appearance has a long history, this particular branch of psychology came into its own during the 1960s and has gained momentum as messages associating physical attractiveness with success and happiness grow more prevalent.[6]

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. Although they may be aware of pattern baldness in their family, many are uncomfortable talking about the issue. Hair thinning is therefore a sensitive issue for both sexes. For sufferers, it can represent a loss of control and feelings of isolation. 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.[7]

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.[8]

Causes[edit]

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

Male pattern hair loss[edit]

Main article: Androgenic alopecia

More than 95% of hair thinning in men is male pattern hair loss (also known as male pattern baldness).[9] Male pattern hair loss is characterized by hair receding from the lateral sides of the forehead (known as a "receding hairline") and/or a thinning crown (balding to the area known as the ‘vertex’).[10] Both become more pronounced until they eventually meet, leaving a horseshoe-shaped ring of hair around the back of the head.

The incidence of pattern baldness varies from population to population and is based on genetic background. Environmental factors do not seem to affect this type of baldness greatly. One large scale study in Maryborough, Victoria, Australia showed the prevalence of mid-frontal baldness increases with age and affects 73.5 percent of men and 57 percent of women aged 80 and over. A rough rule of thumb is that the incidence of baldness in males corresponds to chronological age. For example, according to Medem Medical Library's website, male pattern baldness (MPB) affects roughly 40 million men in the United States. Approximately 25 percent of men begin balding by age 30; two-thirds begin balding by age 60.

There is a 4 in 7 chance of receiving the baldness gene.[11] Onset of hair loss sometimes begins as early as the end of puberty, and is mostly genetically determined. It was previously believed that baldness was inherited from the maternal grandfather. While there is some basis for this belief, both parents contribute to their offspring's likelihood of hair loss. Most likely, inheritance involves many genes with variable penetrance.

The trigger for this type of baldness is dihydrotestosterone, a more-potent form of testosterone often referred to by its acronym DHT. DHT is an androgenic hormone, body- and facial-hair growth promoter that can adversely affect the prostate as well as the hair located on the head.[12] The mechanism by which DHT accomplishes this is not yet fully understood. In genetically prone scalps (i.e., those experiencing male or female pattern baldness), DHT initiates a process of follicular miniaturization, in which the hair follicle begins to deteriorate. As a consequence, the hair’s growth phase (anagen) is shortened, and young, unpigmented vellus hair is prevented from growing and maturing into the deeply rooted and pigmented terminal hair that makes up 90 percent of the hair on the head.[13] In time, hair becomes thinner, and its overall volume is reduced so that it resembles fragile vellus hair or "peach fuzz" until, finally, the follicle goes dormant and ceases producing hair completely.

Nutrition[edit]

Studies have shown that poor nutrition, limited food intake, and deficiencies in certain nutrients can cause thinning. These include deficiencies of biotin, protein, zinc and poor human iron metabolism, although complete baldness is not usually seen. A diet high in animal fats (often found in fast food) and vitamin A is also thought to lead to hair loss.

Infection[edit]

Drugs[edit]

Trauma[edit]

Pregnancy[edit]

Hair loss often follows childbirth without causing baldness. In this situation, the hair is actually thicker during pregnancy due to increased circulating oestrogens. After the baby is born, the oestrogen levels fall back to normal prepregnancy levels, and the additional hair foliage drops out. A similar situation occurs in women taking the fertility-stimulating drug clomiphene.

Other[edit]

The characteristic port-wine stain of Mikhail Gorbachev (here signing the INF Treaty in Washington, 1987) would have remained unknown – if he had not been bald.

Causes of alopecia include:

Pathophysiology[edit]

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.[25] 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[edit]

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.

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.

Management[edit]

Medications[edit]

Treatments for the various forms of hair loss have limited success. Three medications have evidence to support their use in male pattern hair loss: finasteride, dutasteride and minoxidil.[28] They typically work better to prevent further hair loss than to regrow lost hair.[28]

Surgery[edit]

Hair Transplantation is usually carried out under local anaesthetic. 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. **Hair transplants, takes tiny plugs of skin, each which contains a few hairs, and implants the plugs into bald sections. The plugs are generally taken from the back or sides of the scalp. Several transplant sessions may be necessary.[33]

Hiding hair loss[edit]

General Ambrose Burnside (photo by Mathew Brady, c. 1860)

Head[edit]

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—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[edit]

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.

Embracing baldness[edit]

See also: Head shaving

Instead of concealing hair loss, some may embrace it. A shaved head will grow stubble in the same manner and at the same rate as a shaved face. The general public has become accepting of the shaved head as well, though female baldness can be considered less socially acceptable in various parts of the world.

Alternative medicine[edit]

Many people use unproven treatments.[28] Egg oil, in Indian,[34] Japanese, Unani (Roghan Baiza Murgh)[35] and Chinese[36] traditional medicine, was traditionally used as a treatment for hairloss.

Etymology[edit]

The term alopecia /ˌælˈpʃə/ is formed from the Greek alópex (αλώπηξ), 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.

The term bald likely derives from the English word balde, which means "white, pale", or Celtic ball, which means "white patch or blaze", such as on a horse's head.[37]

Research[edit]

There is evidence that the gene SOX21 may play a role in hair loss in humans.[38] There may also be a link between elevated levels of prostaglandin D2 (PDG2) and male pattern hairloss. Abnormally high levels of PDG2 (a nearly three-fold increase) were discovered in tissue samples of balding areas compared to haired areas of the scalp. A PDG2-binding receptor, GPR44, has also been discovered. Compounds aimed at targeting the GPR44 receptor are currently being studied.[39]

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.[40]

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 hairloss and smoking status.[41]

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.[42]

See also[edit]

Footnotes[edit]

  1. ^ "Hair loss". NHS Choices. Retrieved 22 September 2013. 
  2. ^ (/ˌæləˈpʃə/, from Classical Greek ἀλώπηξ, alōpēx, meaning "fox")
  3. ^ "Hair loss, balding, hair shedding. DermNet NZ". Archived from the original on 14 November 2007. Retrieved 2007-12-07. 
  4. ^ ‘Hair growth’, Samer Alaiti, MD, Clinical Associate Professor, Department of Dermatology, University of Southern California: http://emedicine.medscape.com/article/837994-overview
  5. ^ Bergler-Czop, B; Brzezińska-Wcisło, L (2004). "Hormonal factors in etiology of common acne". Polski merkuriusz lekarski : organ Polskiego Towarzystwa Lekarskiego 16 (95): 490–2. PMID 15518435. 
  6. ^ ‘The psychology of appearance: Why health psychologists should "do looks"’, Nichola Rumsey, September 2008: [1]
  7. ^ Passchier J, Erdman J, Hammiche F, Erdman R (2006). "Androgenetic alopecia: stress of discovery". Psychol Rep 98 (1): 226–8. doi:10.2466/PR0.98.1.226-228. PMID 16673981. 
  8. ^ Poot F (2004). "[Psychological consequences of chronic hair diseases]". Revue Médicale de Bruxelles 25 (4): A286–8. PMID 15516058. 
  9. ^ ‘Male Pattern Baldness’, March 01 2010, WebMD
  10. ^ Proctor, PH (1999). "Hair-raising. The latest news on male-pattern baldness". Advance for nurse practitioners 7 (4): 39–42, 83. PMID 10382384. 
  11. ^ "Vitamin E may reverse male pattern baldness: Study". 
  12. ^ Rebora A (2004). "Pathogenesis of androgenetic alopecia". J Am Acad Dermatol 50 (5): 777–9. doi:10.1016/j.jaad.2003.11.073. PMID 15097964. 
  13. ^ "Hair fiber changes with the development of pattern hair loss". Androgeneticalopecia.com. Retrieved 2012-11-16. 
  14. ^ "Infectious hair disease – syphilis". Keratin.com. Retrieved 2011-11-17. 
  15. ^ ‘Drug Induced Hair Loss’, WebMD.com
  16. ^ ‘Drug Induced Hair Loss’, American Hair Loss Association: http://www.americanhairloss.org/drug_induced_hair_loss/
  17. ^ Pappas P, Kauffman C, Perfect J, Johnson P, McKinsey D, Bamberger D, Hamill R, Sharkey P, Chapman S, Sobel J (1995). "Alopecia associated with fluconazole therapy". Ann Intern Med 123 (5): 354–7. doi:10.7326/0003-4819-123-5-199509010-00006. PMID 7625624. 
  18. ^ "Alopecia: Causes". Better Medicine. Retrieved 28 March 2012. 
  19. ^ http://www.webmd.com/skin-problems-and-treatments/hair-loss/drug-induced-hair-loss
  20. ^ Nnoruka E, Nnoruka N (October 2005). "Hair loss: is there a relationship with hair care practices in Nigeria?". Int J Dermatol 44 (Suppl 1): 13–7. doi:10.1111/j.1365-4632.2005.02801.x. PMID 16187950. 
  21. ^ "Anagen Effluvium". Retrieved 2010-06-29. 
  22. ^ Alopecia Areata, by Maria G. Essig, MS, ELS, Yahoo! Health
  23. ^ "Congenital triangular alopecia". Retrieved 2010-06-29. 
  24. ^ "What is Alopecia: What Causes Alopecia?". MedicalBug. 6 February 2012. Retrieved 28 March 2012. 
  25. ^ 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. 
  26. ^ "The hair pull test". Keratin.com. Retrieved 28 March 2012. 
  27. ^ 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. 
  28. ^ a b c 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. 
  29. ^ Joly P (October 2006). "The use of methotrexate alone or in combination with low doses of oral corticosteroids in the treatment of alopecia totalis or universalis". J Am Acad Dermatol. 55 (4): 632–6. doi:10.1016/j.jaad.2005.09.010. PMID 17010743. 
  30. ^ Freyschmidt-Paul P, Ziegler A, McElwee KJ, et al. (2001). "Treatment of alopecia areata in C3H/HeJ mice with the topical immunosuppressant FK506 (Tacrolimus)". Eur J Dermatol 11 (5): 405–9. PMID 11525945. 
  31. ^ Shapiro, J (Dec 2013). "Current treatment of alopecia areata.". The journal of investigative dermatology. Symposium proceedings / the Society for Investigative Dermatology, Inc. [and] European Society for Dermatological Research 16 (1): S42–4. doi:10.1038/jidsymp.2013.14. PMID 24326551. 
  32. ^ Xing, Luzhou et al (2014). "Letter, Alopecia areata is driven by cytotoxic T lymphocytes and is reversed by JAK inhibition". Nature Medicine. doi:10.1038/nm.3645.  Advance online publication retrieved 17 August 2014
  33. ^ ‘Hair Transplants’, WebMD: http://www.webmd.com/skin-problems-and-treatments/hair-loss/hair-transplants
  34. ^ Panda, H (2004). Handbook on Ayurvedic Medicines with Formulae, Processes and Their Uses. ISBN 9788186623633. 
  35. ^ Suresh Babu, S (2002-01-01). Home Made Herbal Cosmetics. ISBN 9788122307757. 
  36. ^ Zhou, Zhongying; Jin, Hui De (1997). Clinical Manual of Chinese Herbal Medicine and Acupuncture. ISBN 9780443051289. 
  37. ^ Harper, Douglas. "Entry for "bald"". Online Etymology Dictionary. Retrieved 2006-12-07. 
  38. ^ Scientists identify gene that may explain hair loss Reporting by Tan Ee Lyn; Editing by Alex Richardson, May 25, 2009, Reuters
  39. ^ "Scientists identify protein responsible for male pattern baldness". Fox News. 21 March 2012. Retrieved 21 May 2012. 
  40. ^ Rebora A (1 July 2001). "Baldness and coronary artery disease: the dermatologic point of view of a controversial issue". Arch Dermatol 137 (7): 943–7. PMID 11453815. 
  41. ^ Asian men who smoke may have increased risk for hair loss
    Su LH, Chen TH (November 2007). "Association of androgenetic alopecia with smoking and its prevalence among Asian men: a community-based survey". Arch Dermatol 143 (11): 1401–6. doi:10.1001/archderm.143.11.1401. PMID 18025364. 
  42. ^ Yamada, Tomohide; Hara, Kazuo; Umematsu, Hitomi; Kadowaki, Takashi (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. 

External links[edit]