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| >>> ABOUT HAIR LOSS IN MEN AND WOMEN |
Normal hair fall is approximately 100 to 125 per day. Fortunately, these hairs are replaced. True hair loss occurs when lost hairs are not regrown or when the daily hair shed exceeds 125 hairs.
Male Pattern Hair Loss (Alopecia Androgenetica)
The most common cause of shedding and hair loss, is also called Male Pattern Baldness, even though 20% of adult women also suffer from it.
Androgenetic Alopecia is an inherited, genetic condition. The genetically affected hair follicles start to produce an enzyme named 5 Alpha Reductase. When the testosterone present in the follicle combines with the enzyme 5 alpha reductase, it produces DHT or dihydrotestosterone (yes women also have testosterone, DHT causes 90% of women's hair loss). Hair follicle receptors are sensitive to DHT and start the process of Male or Female Pattern Hair Loss. DHT causes the hair follicle to shed the normal hair and produce thinner and shorter hair. Over time the miniaturised hair follicles atrophy and die causing permanent hair loss. Finally baldness is reached, a barron area of no hair at all, just tight shiny skin.
The onset of pattern Hair Loss usually begins when men are in their thirties and forties, but the process can begin immediately after puberty in those most severely affected and may progress for decades. The basic etiologic factors in androgenetic alopecia are presumed to be the same in men and women, although phenotypic expression differs. Men commonly show bitemporal recession and vertex thinning, which may progress to an absolute baldness in the affected areas. On the other hand, women with Male pattern baldness (MPB) generally show preservation of the frontal hair line and a progressive thinning on the top of the scalp, but do not develop frank baldness.
It is well established that both genetic and hormonal factors play a role in male pattern hair loss. The genetic factor is by far the more important. Perhaps, when the entire human genome is deciphered early in the third millenium, we will know exactly which gene or genes control MPB. Subsequently, there may be gene therapy for MPB. But for the present, we have only a partial and incomplete understanding of the pathogenesis of MPB.
The alopecia in MPB is caused by progressive miniaturization, rather than destruction of involved hair follicles. In affected follicles, the percentage of hairs in Telogen is increased and the duration of Anagen is decreased. As a consequence, there is relatively more shedding in areas affected by MPB. Since vellus and intermediate hairs have a short Anagen phase, they will shed frequently. There can be permanent hair loss because the replacement hair shaft is finer in texture and lacks the same volume.
The age of onset and the rate of progression of MPB are genetically controlled and cannot be predicted. There are times of remission and, alternately, times of acceleration. When there is a period of acceleration, it is often proceeded by a Telogen Effluvium. Male Pattern hair loss can proceed with alarming speed and everyone is familiar with stories of men who went bald ˜overnight". Unfortunately (and understandably) the patient will blame whatever event or treatment coincided with the accelerated hair loss. Since the dramatic miniaturization of the follicle occurs within one single hair growth cycle, these patients are poorly responsive to treatment and reversing the male pattern hair loss is improbable.
The most common type of hair loss in men and women is Androgenetic Alopecia, also kown as Male or Female Pattern Hair Loss. 95% of all hair loss is from Pattern Hair Loss. See hair loss charts below.
HAIR LOSS CHARTS
Norwood chart of Male Pattern Hair Loss (stages of male hair loss)
| Unlike men, women rarely become "bald" in the true sense, but may expreience significant overall thinning and a reduction in the hair shaft diameter, particularly around the forehead and crown of the scalp as they age. Most often, this pattern begins to develop around age 40 or with the onset of menopause. In fact, before menopause about 13 percent of women experience hair thinning. After menopause, reporting of the problem from women increases to about 37 percent. |
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Ludwig chart of female pattern Hair loss |
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Hair Loss Prevention and Regrowth
Baldness is irreversable. Once a follicle has atrophied it is gone forever and there are no products or remedies that can make a new follicle. But there is good news, further hair loss can be stopped and the hair loss process can be reversed from 1 to 5 years. By using the right treatments further hair loss can be stopped, the miniaturised hairs will become normal hairs again, giving you a fuller, thicker, healthy head of hair. Our_Treatments
OTHER TYPES OF HAIR LOSS
Other Alopecias
Historically, alopecias have been classified as non-scarring or scarring. The scarring type is considered permanent because of the destruction of the follicle and the presence of fibrotic changes. The non-scarring alopecias don't destroy the follicle and there are little or no fibrotic changes around the follicle. Therefore, regeneration of the follicle is theoretically possible. The division can be arbitrary and can often overlap. The transformation of a non-scarring to a scarring alopecia has been identified in some disorders.
Non-Scarring Alopecias
Alterations of hair growth
Telogen effluvium
Anagen effluvium
Miniaturization (i.e. Androgenetic Alopecia)
Congenital
Acquired
Follicular mucinosis
Chemical or physical agent
Trichodystrophies-alterations of hair
Congenital
Acquired
Trichotillomania-traction alopecia
Chemical or physical agents
Infectious agents
Scarring Alopecias
Inflammatory
Lupus erythematosus (chronic type)
Lichen planus pilaris
Planopilaris
Pseudopelade
Scleroderma
Bullous pemphigoid
Epidermolysis bullosa acquista
Folliculitis-secondary to infectious agents
Chemical and physical damage
Granulomatous inflammation
Noninflammatory
Nonscarring pseudopelade
Bullous pemphigoid
Neoplasms-benign and malignant
Many of the causes of alopecia listed above are rare and are not frequently encountered in any practice. A good dermatology textbook will describe the entities. However, it is important to understand that there are many causes for hair loss.
Although it may sound contradictory, shedding and hair loss is not synonymous. First, we must define our terms. Shedding refers to hair shafts that easily or spontaneously fall out of the scalp. There are multiple causes of shedding. Shedding normally occurs at the end of the telogen phase, but, in pathological cases, can also occur during anagen. As a rule, shedding usually refers to a temporary event and suggests that the hair shaft will grow back again as thick as before, providing there is not an intervening pathological process.
In distinction, hair loss can refer to either the temporary or permanent loss of hair or a loss not in the number of hair shafts, but in the volume and texture of the hair shaft. For example, permanent hair loss can be caused by a scarring alopecia, such as occurs in third degree burns or radiation to the scalp. Typical of a loss in the volume of hair, but not in the number of follicles, would be the miniaturization of the follicle due to male pattern baldness (MPB).
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Physiological Shedding
Since it would be normal to have 10 to 15% of all the hairs on the scalp in the telogen phase, we can expect that 50-100 of those hairs are at the end of the phase and will readily shed. The anagen phase is in proportion to the size of the follicle and can vary from months to years. Vellus hairs have an anagen period of a few months. However, regardless of the length of the growing period or of the size of the hair follicle, the length of the telogen phase remains fairly stable, i.e. approximately 100 days. As a consequence, the anagen/telogen ratio in an area affected by male pattern baldness is higher than in areas unaffected or less affected by male pattern baldness (MPB), so in any given time period, there will be more shedding of hair from the areas affected by MPB than there will be in the remainder of the scalp.
At the end of the telogen phase, the follicle will re-enlarge and re-organize and begin producing a new hair shaft. To date, we do not have any medications that can be used safely to shorten the telogen phase.
Shedding Due to Chemical Agents
Minoxidil
For the same reasons that minoxidil promotes hair growth, it can also cause shedding. Despite many years of research and use, the exact physiologic mechanisms whereby minoxidil stimulates hair growth is not known. The stimulatory effect of minoxidil on the hair follicle can cause hair that is in the telogen phase to shed before the end of the normal 100-day telogen period.
The effect of minoxidil on the hair follicles is dose dependent. The initial shedding was rarely reported during use of topical 2% minoxidil. With 5% topical minoxidil, it was usually not noticeable, but was infrequently reported. With the use of currently available minoxidil concentrations of 12.5%, the initial shedding is commonly reported. The shedding can be noted within weeks of initial use of topical minoxidil.
Finasteride
There have been multiple reports of excessive shedding several months after finasteride therapy. Typically, there is a good response to finasteride to prevent or reverse MPB. Then, around the 11th to 16th week, there can be sudden shedding, sometimes on a massive scale. The entire phenomenon fits the description of a telogen effluvium. It is a common observation that post-partum women often suffer the same temporary hair loss. In the case of finasteride use, the telogen effluvium appears to be a reaction to the sudden change in the systemic levels of the sex hormone, DHT. Often the cause of a telogen effluvium are obscure, but has been related to high fevers, stress, trauma, medications, etc.
The shedding is generally diffuse (global) and can affect areas of the scalp not usually affected by MPB. So, it would be common to note shedding from the sides and back of the head in addition to the crown, vertex and frontal areas. The shedding tends to be fairly symmetrical, but will be more noticeable in the areas affected by MPB, because there is a higher ratio of hairs in the telogen phase than in the other areas of the scalp.
The duration of a telogen effluvium is variable, but rarely lasts more than a few months and there is invariably complete restitution unless another pathologic process also occurs.
As a rule, treatment is not necessary because the hair will grow back. For most patients, there is no evidence of residual loss of hair within a year. However, there have been cases of patients taking finasteride and reporting repeated bouts of excessive shedding. In this situation, it would be advisable to discontinue use of finasteride in favor of alternative anti-androgens.
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OTHER TYPES OF HAIR LOSS continued
Telogen Effluvium
This is a common type of temporary hair loss and may occur at any age. The phenomenon represents a precipitous shift of a percentage of anagen hairs to telogen, typically 3 to 4 months after an inciting event. The reaction can be to a variety of physical or emotional stresses:
Etiologies of Telogen Effluvium
Endocrine
Post-partum
Post or peri-menopausal state
Hypo or hyperthyroidism
Nutritional
Caloric or protein deprivation
Zinc deficiency
Biotin deficiency
Iron deficiency
Drugs
Anticoagulants
Angiotensin-converting enzyme inhibitors
Chemotherapeutic agents
Beta blockers
Lithium
Oral contraceptives
Retinoids (e.g. Accutane)
Hypervitaminosis A
Physical stress
Anemia
Systemic illness
Surgery
High fevers
Psychological stress
In a significant number of patients, no obvious cause is found for the Telogen Effluvium. Telogen Effluvium is always potentially completely reversible and does not lead to total scalp loss. Rarely does more than 50% of the hair become involved in a Telogen Effluvium.
Anagen Effluvium
The daily loss of some telogen hairs is entirely normal. It is always abnormal to shed anagen hairs. The term Anagen Effluvium, used to describe the pathologic loss of anagen hairs, is misleading, as the abnormal anagen hairs in this condition are usually broken off rather than shed. An anagen effluvium is an acute, extreme alteration of growth of the majority of anagen follicles, resulting in acute loss of greater than 89-90% of the scalp hair. The hair is usually dystrophic because of the interruption of growth and break off at the level of the scalp. Unlike the shed telogen hair, the Anagen Effluvium hair lost does not have an attached bulb. These sheds occur 1-2 weeks following the precipitating cause and result in an acute, extensive alopecia that can involve 80-90% of the scalp hair.
The classic and easily recognizable causes of Anagen Effluvium of the scalp are radiation therapy to the head and systemic chemotherapy, especially with alkylating agents. In addition, there are a large number of toxic chemicals known to cause anagen effluvium such as poisoning by thallium, mercury or borates. Salts of lead, selenium and arsenic have also been incriminated.
Regrowth of hair can usually be anticipated if the precipitating agent is discontinued or removed. Regrowth after radiation therapy depends on type, depth and dose fractionation. The amount of regrowth is directly related to the amount of damage inflicted upon the hair follicles.
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Alopecia areata Generally thought to be an auto immune disorder. Causes "patchy" hair loss, often in small circular areas in different areas of the scalp.
Alopecia totalis Total hair loss of the scalp, (an advanced form of alopecia areata).
Alopecia universalis Hair loss of the entire body, (also an advanced form of alopecia areata).
Traction alopecia Hair loss caused by physical stress and tension on the hair, such as prolonged use of hair weaving, corn rows etc. Done to tightly on weak hair, these can cause hair loss.
Telogen effiuvium (usually temporary hair loss) Caused by physical stress, emotional stress, thyroid abnormalities, medications and hormonal causes normally associated with females.
Anagen effiuvium Generally due to internally administered medications, such as chemotherapy agents, that poison the growing hair follicle.
Myths related to Hair loss
- Frequent shampooing contributes to hair loss
- Wearing hats and wigs cause hair loss
- Permanent hair loss is caused by perms, colours and other cosmetic treatments
- Stress causes permanent hair loss
- Dandruff causes permanent hair loss
- Hair loss does not occur in the late teens or twenties
- There are treatments or remedies that can produce new hair follicles
- There are cosmetic products that will cause hair to grow thicker and faster
- Cutting ones hair will cause the hair to grow back thicker
- Shaving ones head will cause the hair to grow back thicker.
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