Pattern hair loss is hair loss 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 (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.
Male pattern hair loss seems to be due to a combination of genetics and circulating androgens, particularly dihydrotestosterone (DHT) (DHT).
The cause in female pattern hair loss remains unclear.
Management may include simply accepting the condition or shaving one’s head to improve the aesthetic aspect of the condition. Otherwise, common medical treatments include minoxidil, finasteride, dutasteride, or hair transplant surgery. Use of finasteride and dutasteride in women is not well-studied and may result in birth defects if taken during pregnancyز
Pattern hair loss by the age of 50 affects about half of males and a quarter of females.
It is the most common cause of hair lo
Symptoms and signs (Hair loss)
Classic male-pattern hair loss begins above the temples and at the vertex (calvaria) of the scalp. As it progresses, a rim of hair at the sides and rear of the head remains. This has been referred to as a ‘Hippocratic wreath’, and rarely progresses to complete baldness. A type of non-scarring hair loss, pattern hair loss is characterized as such.
Female-pattern hair loss more often causes diffuse thinning without hairline recession; similar to its male counterpart, female androgenic alopecia rarely leads to total hair loss. The Ludwig scale grades severity of female-pattern hair loss. Hair in women can be graded as Grades 1, 2, or 3 based on the amount of scalp that can be seen on the crown.
In most cases, receding hairline is the first starting point; the hairline starts moving backwards from the front of the head and the sides.
Causes (Hair loss)
Hormones and genes
Hair loss can be triggered by androgens and their interactions with the Wnt signaling pathway.Androgens regulate only one keratin, KRT37. This sensitivity to androgens was acquired by Homo sapiens and is not shared with their great ape cousins. Although Winter et al. found that KRT37 is expressed in all the hair follices of chimpanzees, it was not detected in the head hair of modern humans.
This lack of scalp KRT37 may explain the paradoxical nature of Androgenic alopecia as well as the extraordinarily long anagen cycles of head hair, given that androgens are known to increase hair growth on the body but decrease it on the scalp.
There is evidence to suggest that hair follicle pilosebaceous units begin programming in the womb. The physiology is primarily androgenic, with dihydrotestosterone (DHT) being the major contributor at the dermal papillae.
When compared to men without pattern hair loss, those with premature androgenic alopecia have lower levels of sex hormone-binding globulin (SHBG), follicle stimulating hormone (FSH), testosterone, and epitestosterone.
Recent studies have shown that the scalp contains the stem cell progenitor cells from which the follicles arose, contrary to previous belief that hair follicles were permanently lost in areas of complete hair loss.
The activity of insulin-like growth factor (IGF) at the dermal papillae, which is affected by DHT, has been linked to hair follicle growth and dormancy in transgenic studies. Androgens are important in male sexual development around birth and at puberty.
They regulate sebaceous glands, apocrine hair growth, and libido. With increasing age, androgens stimulate hair growth on the face, but can suppress it at the temples and scalp vertex, a condition that has been referred to as the ‘androgen paradox’.
Men with androgenic alopecia typically have higher 5α-reductase, higher total testosterone, higher unbound/free testosterone, and higher free androgens, including DHT.
alpha-reductase converts free testosterone into DHT, and is highest in the scalp and prostate gland. 5-reduction of testosterone is the most common way for DHT to form in the body’s tissues. There has been a breakthrough in identifying the enzyme’s genetic corollary. Prolactin has also been suggested to have different effects on the hair follicle across gender.
Also, crosstalk occurs between androgens and the Wnt-beta-catenin signaling pathway that leads to hair loss. At the level of the somatic stem cell, androgens promote differentiation of facial hair dermal papillae, but inhibit it at the scalp. A different line of research points to the hair follicles as a source of the hormone prostaglandin D2 synthase and its product, prostaglandin D2 (PGD2).
These observations have led to study at the level of the mesenchymal dermal papillae. Individual hair follicle papillae contain pilosebaceous units containing types 1 and 2 5 reductase enzymes. They catalyze formation of the androgens testosterone and DHT, which in turn regulate hair growth. Androgens stimulate IGF-1 in facial hair, leading to growth, but they can also stimulate TGF 1, TGF 2, dickkopf1, and IL-6 in the scalp, leading to catagenic miniaturization. They can also stimulate TGF 2, dickkopf1, and IL-6.
Hair follicles in anaphase express four different caspases. Significant levels of inflammatory infiltrate have been found in transitional hair follicles. Interleukin is suspected to be a cytokine mediator that promotes hair loss.
The fact that hair loss is cumulative with age while androgen levels fall as well as the fact that finasteride does not reverse advanced stages of androgenetic alopecia remains a mystery, but some possible explanations have been put forward: In balding scalps, 5-alpha reductase levels rise, indicating higher testosterone-to-DHT conversion rates, while androgen receptor activation and environmental stress both increase DNA damage in the dermal papilla and the senescence of the dermal papilla.
Dermal papilla permanent senescence may be brought on by the androgen receptor in conjunction with IL6, TGFB-1, and/or oxidative stress, but the exact mechanism is unknown. Senescence of the dermal papilla is measured by lack of mobility, different size and shape, lower replication and altered output of molecules and different expression of markers.
The dermal papilla is the primary location of androgen action and its migration towards the hair bulge and subsequent signaling and size increase are required to maintain the hair follicle so senescence via the androgen receptor explains much of the physiology.
Diagnosis (Hair loss)
The diagnosis of androgenic alopecia can be usually established based on clinical presentation in men. In women, the diagnosis usually requires more complex diagnostic evaluation. Further evaluation of the differential requires the exclusion of other causes of hair loss and the assessment of the typical pattern of progressive hair loss of androgenic alopecia. alopecia.
Trichoscopy is a technique that can be used to perform more in-depth examinations. Biopsy may be needed to exclude other causes of hair loss, and histology would demonstrate perifollicular fibrosis.
It was decided to use the Hamilton–Norwood scale to determine the severity of androgenic alopecia in males.
Treatment (Hair loss)
Finasteride is a medication of the 5α-reductase inhibitors (5-ARIs) class. By inhibiting type II 5-AR, finasteride prevents the conversion of testosterone to dihydrotestosterone in various tissues including the scalp.
Within three months of beginning finasteride treatment, an increase in the amount of hair on the scalp can be seen, and studies conducted over the course of 24 and 48 months have also shown an increase in hair growth.
Treatment with finasteride more effectively treats male-pattern hair loss at the crown than male-pattern hair loss at the front of the head and temples.
Finasteride belongs to the same class as dutasteride, but dutasteride inhibits 5-alpha reductase of both types I and II. Although it is legal in Korea and Japan to use dutasteride for the treatment of male-pattern hair loss, it is not in the United States of America. However, it is commonly used off-label to treat male-pattern hair loss.
Minoxidil dilates small blood vessels; it is not clear how this causes hair to grow. Tretinoin plus minoxidil, ketoconazole shampoo, dermarolling, spironolactone, alfatradiol, and topilutamide are other options (fluridil).
A woman’s body pattern
Minoxidil has been shown to be an effective and safe treatment for female pattern hair loss, with no discernible difference in effectiveness between formulations containing 2 percent and 5 percent minoxidil. Based on low-quality studies, finasteride was found to be no more effective than a placebo in treating hair loss. The effectiveness of laser-based therapies is unclear. Bicalutamide, an antiandrogen, is another option for the treatment of female pattern hair loss.
Hair transplantation may be necessary in more advanced cases that are resistant to or do not respond to medical treatment. Naturally occurring units of one to four hairs, called follicular units, are excised and moved to areas of hair restoration.
A large number of these follicular units are surgically implanted in the scalp in close proximity. Follicular unit transplantation (FUT) or follicular unit extraction (FUE) yields the grafts (FUE). In the former, a strip of skin with follicular units is extracted and dissected into individual follicular unit grafts, and in the latter individual hairs are extracted manually or robotically.
The grafts are then implanted into the recipient sites, which are small incisions made by the surgeon. A buzzed-back haircut can be simulated with cosmetic scalp tattoos.
Various treatment options
Many people use unproven treatments. Regarding female pattern alopecia, there is no evidence for vitamins, minerals, or other dietary supplements. As of 2008, there is little evidence to support the use of lasers to treat male-pattern hair loss The same applies to special lights. Dietary supplements are not typically recommended. An analysis conducted in 2015 found an increasing number of papers examining the effects of plant extracts but only one randomized controlled clinical trial, which examined the effects of saw palmetto extract on ten individuals.
Androgenetic alopecia is a common form of hair loss in both men and women. Also known as male-pattern baldness in men, this condition is a common occurrence in this gender. Hair is lost in a well-defined pattern, beginning above both temples. The hairline develops a distinctive “M” shape as it thins with age. Hair also thins at the crown (near the top of the head), often progressing to partial or complete baldness.
In contrast to male-pattern baldness, women experience hair loss in a different pattern. Women’s hair thins out all over the head, but the hairline doesn’t move backward as it does in men. In women, androgenetic alopecia rarely results in complete hair loss.
Androgenetic alopecia in men has been associated with several other medical conditions including coronary heart disease and enlargement of the prostate. Androgenetic alopecia has also been linked to prostate cancer, insulin resistance disorders (such as diabetes and obesity), and high blood pressure (hypertension). In women, this form of hair loss is associated with an increased risk of polycystic ovary syndrome (PCOS) (PCOS). Menstrual irregularities, acne, excessive body hair (hirsutism), and weight gain are all symptoms of PCOS, which is characterized by a hormonal imbalance.
Hair loss in men and women is frequently caused by androgenetic alopecia. An estimated 50 million men and 30 million women in the United States suffer from this type of hair loss. Androgenetic alopecia can start as early as a person’s teens and risk increases with age; more than 50 percent of men over age 50 have some degree of hair loss. Hair loss is more common in women after menopause.
Androgenetic alopecia is most likely caused by a combination of genetic and environmental factors. Despite the fact that researchers are looking into possible risk factors, the majority of these factors are still unknown. Researchers have found a link between this type of hair loss and androgens, particularly dihydrotestosterone, an androgen.
Androgens play an important role in the normal development of male sexuality in adolescence. Hair growth and sex drive are two other important functions of androgens in men and women.
Hair growth begins under the skin in structures called follicles. Each strand of hair normally grows for 2 to 6 years, goes into a resting phase for several months, and then falls out. The cycle starts over when the follicle begins growing a new hair. Hair follicles with higher levels of androgens may experience a shorter hair growth cycle and produce hair that is finer and thinner in texture. Additionally, there is a delay in the growth of new hair to replace strands that are shed.
Although researchers suspect that several genes play a role in androgenetic alopecia, variations in only one gene, AR, have been confirmed in scientific studies. The AR gene provides instructions for making a protein called an androgen receptor.
Dihydrotestosterone and other androgens are recognized by the body through the presence of androgen receptors. Studies suggest that variations in the AR gene lead to increased activity of androgen receptors in hair follicles. It remains unclear, however, how these genetic changes increase the risk of hair loss in men and women with androgenetic alopecia.
Male pattern hair loss has been linked to a number of different health problems, such as heart disease, prostate cancer, and polycystic ovary syndrome, which researchers are still studying.
They believe that some of these disorders may be associated with elevated androgen levels, which may help explain why they tend to occur with androgen-related hair loss. Other hormonal, environmental, and genetic factors that have not been identified also may be involved.
The inheritance pattern of androgenetic alopecia is unclear because many genetic and environmental factors are likely to be involved. Having a close relative with patterned hair loss appears to be a risk factor for developing this condition, as it tends to occur in families.
Other Names for This Condition (Hair loss)
Male pattern hair loss Female pattern baldness The alopecia aerate in men Hair loss in men with a typical male pattern Baldness that has a pattern