Baldness

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Alopecia
Classifications and external resources
Actor Patrick Stewart
ICD-10 L63-L64
ICD-9 704.0

Baldness is a trait which involves the state of lacking hair where it often grows, especially on the head. The most common form of baldness is a progressive hair thinning condition called androgenic alopecia or 'male pattern baldness' that occurs in adult human males and some primate species. The severity and nature of baldness can vary greatly; it ranges from male and female pattern alopecia (androgenetic alopecia, also called androgenic alopecia or alopecia androgenetica), alopecia areata, which involves the loss of some of the hair from the head, and alopecia totalis, which involves the loss of all head hair, to the most extreme form, alopecia universalis, which involves the loss of all hair from the head and the body. Treatment for alopecia has limited success. The more hair lost, the less successful the treatment will be.

Contents

[edit] Background, cause and incidence

The most noticeable part of human hair is the hair on the head, which is more dense than most hair found elsewhere on the body. The average human head has about 100,000 hair follicles.[1] Each follicle can grow about 20 individual hairs in a person's lifetime.[1] Average normal hair loss is about 100 strands a day.

Incidence of pattern baldness varies from population to population based on diet and personal habits. One large scale study in Maryborough, in central Victoria (Australia) showed the prevalence of mid-frontal hair loss increases with age and affects 57% of women and 73.5% of men aged 80 and over.

Male pattern baldness is characterized by hair receding from the lateral sides of the forehead, known as "receding hairline" or "receding brow." An additional bald patch may develop on top (vertex). The trigger for this type of baldness (called androgenic alopecia because it is caused by male hormones or androgens) is DHT, a powerful sex hormone.[2]

The mechanism by which DHT accomplishes this is not yet understood. In genetically-prone scalps, DHT initiates a process of follicular miniaturization. Through the process of follicular miniaturization, hair shaft width is progressively decreased until scalp hair resembles fragile vellus hair or "peach fuzz" or else becomes non-existent. Onset of hair loss sometimes begins as early as end of puberty, and is mostly genetically determined. Male pattern baldness is classified on the Hamilton-Norwood scale I-VIII.

It was previously believed that baldness was inherited from a person's maternal grandfather. While there is some basis for this belief, both parents contribute to their offspring's likelihood of hair loss. Most likely, inheritance is technically "autosomal dominant with mixed penetrance" (see 'baldness folklore' below)

There are several other kinds of baldness:

  • Traction alopecia is most commonly found in people with ponytails or cornrows who pull on their hair with excessive force. Wearing a hat shouldn't generally cause this, though it is a good idea to let your scalp breathe for 7 hours a day[citation needed].
  • Traumas such as chemotherapy, childbirth, major surgery, poisoning, and severe stress may cause a hair loss condition known as telogen effluvium.[3]
  • Some mycotic infections can cause massive hair loss.[4]
  • Alopecia areata is an autoimmune disorder also known as "spot baldness" that can result in hair loss ranging from just one location (Alopecia areata monolocularis) to every hair on the entire body (Alopecia areata universalis).
  • Localized or diffuse hair loss may also occur in cicatricial alopecia (lupus erythematosus, lichen plano pilaris, folliculitis decalvans, central centrifugal cicatricial alopecia, postmenopausal frontal fibrosing alopecia, etc.). Tumours and skin outgrowths also induce localized baldness (sebaceous nevus, basal cell carcinoma, squamous cell carcinoma).
  • Hypothyroidism can cause hair loss, especially thinning of the outer third of the eyebrows

[edit] Etymology

The term alopecia (al-oh-PEE-she-uh) is formed from the Greek αλώπηξ (alopex), meaning fox. The origin of this usage is because this animal sheds its coat twice a year.

The term bald derives from the English word balde, which means "white", or Celtic ball, which means "white patch or blaze", such as on a horse's head.[5]

[edit] Approaches to baldness

[edit] Psychological implications

The psychological implications for individuals experiencing hair loss vary widely. Some people adapt to the change very well, others have severe problems relating to anxiety, depression, social phobia, and in some cases, problems with identity change.

Alopecia 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 (what is called alexithymia) and may be more prone to avoiding family conflicts. Family therapy can help families to cope with these psychological problems if they arise.[6]

Psychological problems due to baldness, if present, are typically most severe at the onset of symptoms.[7]

Some balding men may feel proud of their baldness, feeling a kindred relationship with famous charismatic bald film actors such as Yul Brynner, Vin Diesel, Michael Chiklis, Telly Savalas, Ben Kingsley, Patrick Stewart or Bruce Willis; or politicians such as Ed Koch; or sportsmen such as wrestler Stone Cold Steve Austin, footballer Zinedine Zidane or tennis star Andre Agassi. Much of these celebrities' perceived masculinity and handsomeness derives from their most obvious distinguishing feature. This is not yet true for women, as there are few female celebrities who are bald by choice, chemotherapy or genetics/environment.

Many companies have built a successful business selling products that reverse baldness, by allegedly regrowing hair, transplanting hair or selling hairpieces. There is very little evidence that any of those which claim hair regrowth actually work.

[edit] Preventing and reversing hair loss

Main article: Baldness treatments

It is easier to prevent the falling out of healthy hairs than to regrow hair in follicles that are already dormant. Finasteride (marketed in the U.S. as Propecia) and minoxidil (marketed in the U.S. as Rogaine, and some places as Regaine) have shown some success in partially reversing loss. In a one-year study of finasteride, evaluation after one year showed five of 21 subjects (23.8%) had two-grade improvement in MNHS grade on a modified Norwood/Hamilton scale and 12 of 21 subjects (57.1%) had one-grade improvement; the others remained at the same grade.[8] However such treatments are generally ineffective at treating extreme cases of hair loss.[9]

Surgery is another method of reversing hair loss and baldness, although it may be considered an extreme measure. The surgical methods used include hair transplantation, where patches of skin with hair are moved from one part of the head to another.

Looking forward, the prospective treatment of hair multiplication/hair cloning, which extracts self-replenishing follicle stem cells, multiplies them many times over in the lab, and microinjects them into the scalp, has been shown to work in mice, and is currently under development, expected by some scientists to be available to the public in 2009–2015. Subsequent versions of the treatment are expected by some scientists to be able to cause these follicle stem cells to simply signal the surrounding hair follicles to rejuvenate. See Baldness treatments

Topical application of ketoconazole, which is both an anti-fungal and a potent 5-alpha reductase inhibitor, is often used as a supplement to other approaches.

Interestingly, placebo treatments in studies often have reasonable success rates, though not as high as the products being tested, and even similar side-effects as the products. For example, in Finasteride (Propecia) studies, the percent of patients with any drug-related sexual adverse experience was 3.8% compared with 2.0% in the placebo group.[10]

Regular aerobic exercise can help keep androgen levels naturally lower while maintaining overall health and lowering stress, though weight training may have a detrimental effect on hair by increasing testosterone levels.[citation needed]Stress reduction can be helpful in slowing hair loss.[citation needed]Immunosuppressants applied to the scalp have been shown to temporarily reverse hair loss, though the possibly lethal side effects of this treatment make it untenable.[citation needed]Saw Palmetto (Serenoa repens) is an herbal DHT inhibitor often claimed to be cheaper and have fewer side effects than finasteride and dutasteride. Unlike other 5alpha-reductase inhibitors, Serenoa repens induces its effects without interfering with the cellular capacity to secrete PSA.[11] Saw palmetto extract has been demonstrated to inhibit both isoforms of 5-alpha-reductase unlike finasteride which only inhibits the (predominant) type 2 isoenzyme of 5-alpha-reductase.[12][13][14]

Polygonum Multiflorum is a traditional Chinese cure for hair loss. Whether the plant itself is useful, the general safety and quality control of herbs imported from China can be questionable.

Beta Sitosterol, which is a constituent in many seed oils, can help to treat BHP by lowering cholesterol. If used for this purpose, an extract is best. Consuming large amounts of oil to get at small quantities of beta sitosterol is likely to exacerbate male pattern baldness.

Resveratrol, from grape skins, is a lipase inhibitor. By decreasing the body's ability to absorb fat through the intestine walls, it reduces the total fat and calorie content of a person's diet.

While drastic, broad spectrum anti-androgens such as flutamide are sometimes used topically. Flutamide is potent enough to have a feminizing effect in men, including growth of the breasts.

In March 2006, Curis announced that it had received the first preclinical milestone, a $1,000,000 cash payment, in its hair growth program with Procter & Gamble Pharmaceuticals, a division of The Procter & Gamble Company. The program is focused on the potential development of a topical Hedgehog agonist for hair growth disorders, such as male pattern baldness and female hair loss.[15]

In October 2006, UK biotechnology firm Intercytex announced they have successfully tested a method of removing hair follicles from the back of the neck, multiplying them and then reimplanting the cells into the scalp (Hair multiplication). The initial testing resulted in 70% of male patients regrowing hair. This treatment method is expected to be available to the public by 2009 [2][3].

[edit] Concealing hair loss

[edit] Head

John D. Rockefeller, who had alopecia universalis, with toupee
Enlarge
John D. Rockefeller, who had alopecia universalis, with toupee

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. When this reaches a stage of extreme effort with little effect — it can make the person the object of teasing or scorn.

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 such as Wigs for Kids and Locks of Love 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.

[edit] Eyebrows

Though not as common as the loss of hair on the head, chemotherapy, hormone imbalance, forms of alopecia, and other factors can also cause loss of hair in the eyebrows. Artificial eyebrows are available to replace missing eyebrows or to cover patchy eyebrows.

[edit] Embracing baldness

Of course, instead of concealing hair loss, one may embrace it. A shaved head will grow stubble in the same manner and at the same rate as a shaved face. Many celebrities and athletes shave their heads. They spread the message of baldness by shaving the heads of adults to raise money for curing childhood cancer, which often causes children to lose their hair (see Head shaving). Female baldness is less socially accepted. Sharon Blynn, Bald Is Beautiful founder and an ovarian cancer survivor whose motto is "Always smile from the inside out!" encourages women to define beauty for themselves on their own terms.

[edit] Baldness folklore

There are many myths regarding the possible causes of baldness and its relationship with one's virility, intelligence, ethnicity, job, social class, wealth etc. While skepticism is warranted due to lack of scientific validation, some of these myths may have a degree of underlying truth.

  • "You inherit baldness from your mother's father."
    Previously, early baldness of the androgenic type was thought to be sex linked dominant in males and to be sex linked recessive in females.
    Research suggests that the gene for the androgen receptor, which is significant in determining probability for hair loss, is located on the X chromosome and so is always inherited from the mother's side.[16]There is a 50% chance that a person shares the same X chromosome as their maternal grandfather. Because women have two X chromosomes, they will have two copies of the androgen receptor gene while men only have one.
    However research has also shown that a person with a balding father also has a significantly greater chance of experiencing hair loss.[17]
  • "Intellectual activity or psychological problems can cause baldness."
    This myth probably was inspired by the fact that the human brain is located inside the skull, very close and just below where hair grows, and so it was thought that the use and abuse as well as mental diseases could have negative effect on hair growth and number.[citation needed] It may also be due to the fact that cholesterol is involved in the process of neurogenesis and also the base material from which the body ultimately manufactures DHT. While the notion that bald men are more intelligent may lack credibility in the modern world, in the ancient world if a person was bald it was likely that he had an adequate amount of fat in his diet. Thus, his mental development was probably not stunted by malnutrition during his crucial formative years, he was more likely to be wealthy, and also have had access to a formal education. However a sedentary lifestyle is less likely to correlate with intelligence in the modern world, and dietary fat content is less strongly linked to economic class in developed countries.
    This is sometimes used as a stereotype in films, where the more intellectual or rather frustrated characters are most usually portrayed as bald and generally unattractive, as opposed to the main characters which are usually portrayed as attractive, fit, mentally stable and generally with no apparent hair problems.
    This same myth normally extends to considering people having intellectual jobs more prone to baldness problems compared to manual laborers, sometimes further extending the myth to male college or university students when compared to workers of the same age.[citation needed] The myth is suspect because counterexamples can be found in any case.
    There is evidence, confirmed by cross cultural studies, for an association between androgen levels and intellectual ability. These findings are controversial due to their implications regarding psychology and gender.
    Total testosterone exhibits a positive relation to tactual-spatial abilities and to the degree of lateralization. Total testosterone is negatively correlated with verbal fluency. Testosterone in the saliva is also significantly positively correlated to tactual-spatial test scores and, in addition, to field independence. DHT and the ratio DHT/total testosterone are positively related to verbal fluency and negatively to the degree of lateralization of tactual-spatial performance.[18]
  • "Baldness can be caused by emotional stress, sexual frustration etc."
    Emotional stress has been shown to accelerate baldness in genetically susceptible individuals.[19]
    Stress due to sleep deprivation in military recruits lowered testosterone levels, but is not noted to have effected SHBG.[20]
    Thus, stress due to sleep deprivation in fit males is unlikely to elevate DHT. Whether it can cause hair loss by some other mechanism is not clear.
  • "Bald men are more "virile" or sexually active than others."
    Levels of free testosterone are strongly linked to libido and also DHT levels, but unless free testosterone is virtually non-existent levels have not been shown to affect virility. Men with androgenic alopecia are more likely to have a higher baseline of free androgens. However sexual activity is multifactoral, and androgenic profile is also not the only determining factor in baldness. Additionally, because hair loss is progressive and free testosterone declines with age, a person's hairline may be more indicative of their past than present disposition. [21][22]
  • "Shaving hair makes it grow back stronger"
    Proposed as a popular remedy against baldness, it's very probably just an illusion similar to the one perceived after shaving one's beard or mustache. Shaving one's head doesn't increase the number of healthy hair present on the scalp, and, after the remaining hair has grown a few millimeters, no enhancement in thickness or overall quality can be observed.
  • "Frequent ejaculation causes baldness"
    There are many misconceptions about what can help prevent hairloss, one of these being that frequent ejaculation may have an influence on MPB. While ejaculation significantly lowers levels of relaxin (a 5-alpha reductase inhibitor) in a male's body and causes testosterone levels to temporarily elevate, the claim that frequent ejaculations can cause baldness is often viewed with skepticism. Higher free testosterone levels may correlate with both hairloss and increased sex drive in predisposed individuals.
  • "Standing on one's head alleviates baldness"
    The "blood-flow" theory, which led men to stand on their heads in the 1980's, can be found in the advertising for many of the fake hair-loss treatments for sale on the internet. While Minoxidil is a vasodilator and is speculated to work, in part, by increasing blood flow to hair follicles, there is no evidence that standing on one's head can alleviate baldness.
  • "Tight hats cause baldness."
    This one probably started in the military where young men entering the service were required to wear hats and soon showed signs of going bald, or at least of hair thinning. This is due to coincidental timing. The age that young men enter the military is also the same age that male pattern hair loss begins. This is due to dihydrotestosterone, not hats. Hats do cause hair breakage and, to a lesser degree, split ends. Since hats are not washed as frequently as other clothing, they can also lead to scalp uncleanliness and possible P. ovale contamination in men with naturally oily scalps.

[edit] Trivia

  • John D. Rockefeller had an extreme case of alopecia that caused him to lose all of the hair on his face, including his eyebrows and eyelashes. Another famous person who suffers from similarly severe alopecia is Italian football referee Pierluigi Collina. Actor Patrick Stewart lost most of his hair to male-pattern baldness by age 19 (His natural "horse-shoe" of remaining hair can be seen in the film L.A. Story, along with his numerous appearances as Captain Jean-Luc Picard in Star Trek).
  • Eunuchs rarely go bald, due to to reduced hormone levels.[23]
  • Baldness is not only a human trait. Some other primates, such as Chimpanzees, stump-tailed macaques, and South American nakari show progressive thinning of the hair on the scalp after adolescence. Adult stump-tailed macaques, in fact, are commonly used in laboratories for the testing of hair-regrowth treatments.
  • The different predecessors of Old World and New World vultures convergently evolved a bald head, preventing feathers from retaining material from the vulture's diet of rotting meat, as well as helping in heat regulation.[24][25]
  • The American Bald Eagle is not really bald. The feathers on the head of this bird are white, in contrast to the brown feathers of the body. The term "bald" derives from the English word balde, which means "white".
  • Little Britain actor and creator Matt Lucas has suffered from Alopecia Universalis since the age of 6 and has since utilised his situation in the creation of popular characters from Little Britain, such as Andy.

[edit] See also

[edit] References

  • Muscarella, F., & Cunningham, M.R. (1996). "The evolutionary significance and social perception of male pattern baldness and facial hair". Ethology and Sociobiology 17: 99-117.
  • Rossi S (Ed.) (2004). Australian Medicines Handbook 2004. Adelaide: Australian Medicines Handbook. ISBN 0-9578521-4-2
  • ^ This article incorporates content from the 1728 Cyclopaedia, a publication in the public domain.
  • Stárka L, Cermáková I, Dusková M, Hill M, Dolezal M, Polácek V (2004). "Hormonal profile of men with premature balding.". Exp Clin Endocrinol Diabetes 112 (1): 24-8. PMID 14758568.

[edit] Footnotes

  1. ^ "Growth of Human Hair" Procter & Gamble, 2003.
  2. ^ Rebora A (2004). "Pathogenesis of androgenetic alopecia.". J Am Acad Dermatol 50 (5): 777-9. PMID 15097964.
  3. ^ Nnoruka E, Nnoruka N (Oct 2005). "Hair loss: is there a relationship with hair care practices in Nigeria?". Int J Dermatol 44 Suppl 1: 13-7. PMID 16187950.
  4. ^ 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. PMID 7625624.
  5. ^ Harper, Douglas. Entry for "bald". Online Etymology Dictionary. Retrieved on 2006-12-07.
  6. ^ Poot F (2004). "[Psychological consequences of chronic hair diseases]". Rev Med Brux 25 (4): A286-8. PMID 15516058.
  7. ^ Passchier J, Erdman J, Hammiche F, Erdman R (2006). "Androgenetic alopecia: stress of discovery.". Psychol Rep 98 (1): 226-228. PMID 16673981.
  8. ^ Lin J, Chen W (2002). "Finasteride in the treatment of Taiwanese men with androgenetic alopecia: a 12-month open-label study.". Kaohsiung J Med Sci 18 (8): 379-85. PMID 12476680.
  9. ^ Meidan V, Touitou E (2001). "Treatments for androgenetic alopecia and alopecia areata: current options and future prospects.". Drugs 61 (1): 53-69. PMID 11217871.
  10. ^ Leyden J, Dunlap F, Miller B, Winters P, Lebwohl M, Hecker D, Kraus S, Baldwin H, Shalita A, Draelos Z, Markou M, Thiboutot D, Rapaport M, Kang S, Kelly T, Pariser D, Webster G, Hordinsky M, Rietschel R, Katz H, Terranella L, Best S, Round E, Waldstreicher J (1999). "Finasteride in the treatment of men with frontal male pattern hair loss." (pdf). J Am Acad Dermatol 40 (6 Pt 1): 930-7. PMID 10365924.
  11. ^ Habib F, Ross M, Ho C, Lyons V, Chapman K (2005). "Serenoa repens (Permixon) inhibits the 5alpha-reductase activity of human prostate cancer cell lines without interfering with PSA expression.". Int J Cancer 114 (2): 190-4. PMID 15543614.
  12. ^ Prager N, Bickett K, French N, Marcovici G (2002). "A randomized, double-blind, placebo-controlled trial to determine the effectiveness of botanically derived inhibitors of 5-alpha-reductase in the treatment of androgenetic alopecia.". J Altern Complement Med 8 (2): 143-52. PMID 12006122.
  13. ^ Marks L, Hess D, Dorey F, Luz Macairan M, Cruz Santos P, Tyler V (2001). "Tissue effects of saw palmetto and finasteride: use of biopsy cores for in situ quantification of prostatic androgens.". Urology 57 (5): 999-1005. PMID 11337315.
  14. ^ Iehlé C, Délos S, Guirou O, Tate R, Raynaud J, Martin P (1995). "Human prostatic steroid 5 alpha-reductase isoforms — a comparative study of selective inhibitors.". J Steroid Biochem Mol Biol 54 (5-6): 273-9. PMID 7577710.
  15. ^ "Curis and Procter & Gamble Enter into R&D Agreement for Hair Growth Program". Retrieved on 2006-08-24.
  16. ^ Hillmer A, Hanneken S, Ritzmann S, Becker T, Freudenberg J, Brockschmidt F, Flaquer A, Freudenberg-Hua Y, Jamra R, Metzen C, Heyn U, Schweiger N, Betz R, Blaumeiser B, Hampe J, Schreiber S, Schulze T, Hennies H, Schumacher J, Propping P, Ruzicka T, Cichon S, Wienker T, Kruse R, Nothen M (2005). "Genetic variation in the human androgen receptor gene is the major determinant of common early-onset androgenetic alopecia.". Am J Hum Genet 77 (1): 140-8. PMID 15902657.
  17. ^ Chumlea W, Rhodes T, Girman C, Johnson-Levonas A, Lilly F, Wu R, Guo S (2004). "Family history and risk of hair loss.". Dermatology 209 (1): 33-9. PMID 15237265.
  18. ^ Christiansen K (1993). "Sex hormone-related variations of cognitive performance in !Kung San hunter-gatherers of Namibia.". Neuropsychobiology 27 (2): 97-107. PMID 8515835.
  19. ^ Schmidt J (1994). "Hormonal basis of male and female androgenic alopecia: clinical relevance.". Skin Pharmacol 7 (1-2): 61-6. PMID 8003325.
  20. ^ Remes K, Kuoppasalmi K, Adlercreutz H (1985). "Effect of physical exercise and sleep deprivation on plasma androgen levels: modifying effect of physical fitness.". Int J Sports Med 6 (3): 131-5. PMID 4040893.
  21. ^ Toone B, Wheeler M, Nanjee M, Fenwick P, Grant R (1983). "Sex hormones, sexual activity and plasma anticonvulsant levels in male epileptics.". J Neurol Neurosurg Psychiatry 46 (9): 824-6. PMID 6413659.
  22. ^ Davidson J, Kwan M, Greenleaf W (1982). "Hormonal replacement and sexuality in men.". Clin Endocrinol Metab 11 (3): 599-623. PMID 6814798.
  23. ^ HAMILTON J (Oct 1960). "Effect of castration in adolescent and young adult males upon further changes in the proportions of bare and hairy scalp." (Abstract). J Clin Endocrinol Metab 20: 1309–18. PMID 13711016.
  24. ^ Stanley Rice (September 1987). "On the Problem of Apparent Evil in the Natural World". Perspectives on Science and Christian Faith 39: 150-157.
  25. ^ Fiona Sunquist (September/October 1996). Two Species, One Design ((Google cached)). National Wildlife Federation.

[edit] External links

[edit] Male Pattern Baldness News

[edit] The relationship between androgenic baldness, metabolism, diabetes and heart disease

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