Hair

Female Androgenetic Alopecia

While the patterns of baldness for men and women differ, they both have a common genetic cause. With male pattern baldness, hair loss typically occurs on the top and front of the head. With female pattern baldness, thinning occurs on the top and crown of the head.

This thinning in women often starts as a widening of the centre hair part that leaves the front hairline unaffected. Medication may prevent further hair loss. In some cases, surgeons can transplant hair or reduce the area of bald skin. Natural-looking wigs and hairpieces can help cover hair loss.

Common Types

The majority of women with androgenetic - also called androgenic - alopecia have diffuse thinning on all areas of the scalp. Androgenic alopecia in women is due to the action of androgens, male hormones that are typically present in only small amounts.
Androgenic alopecia can be caused by a variety of factors tied to the actions of hormones, including some ovarian cysts, taking high androgen index birth control pills, pregnancy, and menopause.
When your body goes through something traumatic like child birth, malnutrition, a severe infection, major surgery, or extreme stress, it can impact your hair. Many of the 90% or so of hairs in the growing (anagen) or transitional (catagen) phases can actually shift all at once into the resting (telogen) phase.
For most who suffer with this, complete remission is probable as long as severely stressful events can be avoided. For some women, however, telogen effluvium is a mysterious chronic disorder and can persist for months or even years without any true understanding of the triggering factors or stressors.
Anagen effluvium occurs after any insult to the hair follicle that impairs its cellular-level mitotic or metabolic activity. This hair loss is commonly associated with chemotherapy. Since chemotherapy targets rapidly dividing cancer cells, your body's other rapidly dividing cells -- such as hair follicles in the growing (anagen) phase -- are also greatly affected. Soon after chemotherapy begins, approximately 90% or more of hairs in the anagen phase can fall out.
This condition is caused by localized trauma to the hair follicles from tight hairstyles that pull at the hair over time. If the condition is detected early enough, the hair will regrow. Braiding, cornrows, tight ponytails, and extensions are the most common styling causes of traction alopecia.

Male Androgenetic Alopecia

Male pattern hair loss is the most common cause of balding. The pathogenesis involves androgen, and in particular dihydrotestosterone, binding to androgen receptors in the dermal papilla of sensitive hair follicles. Hair follicle sensitivity is genetically determined and shows regional specificity. Androgen stimulation of scalp dermal papilla cells induces transforming growth factor beta (TGF-B) and results in cyclical miniaturization of the entire hair follicle. The resulting hair produced from that follicle is shorter and finer and provides less complete scalp coverage.

In contrast androgen stimulation of beard dermal papilla cells produces insulin growth factor -2 (IGF-2) and results in cyclical enlargement of the entire hair follicle. The resulting hair produced from that follicle is longer and thicker and provides more complete facial skin coverage. Some degree of androgenetic alopecia is universal among ageing men, especially bitemporally, however less than half become bald in the Hippocratic sense. Although scalp hair coverage has little functional importance, it has cosmetic significance.
Baldness changes the facial appearance of affected men. When that change is perceived as adverse it has the potential to produce emotional morbidity.

Frequently asked questions

Male pattern hair loss is an inherited condition, caused by a genetically determined sensitivity to the effects of dihydrotestosterone, or DHT in some areas of the scalp. DHT is believed to shorten the growth, or anagen, phase of the hair cycle, from a usual duration of 3–6 years to just weeks or months. This occurs together with miniaturisation of the follicles, and progressively produces fewer and finer hairs. The production of DHT is regulated by an enzyme called 5-alpha reductase.
All hair follicles are replaced at different rates by the normal process of hair cycling. Hair growth alternates between phases of activity and rest. The growth period, called the anagen phase, lasts for two to six years. During this time, the follicle is long and deep, and produces thick, well-pigmented hair. About 90% of all scalp hairs are in the anagen phase at a given time.
Anagen is followed by a brief transition phase known as the catagen phase, which lasts 1–2 weeks. During this time, the base of the follicle shrivels. The resting period, or telogen phase, follows catagen and lasts for 3 months. In this phase, the shrunken follicle retains the hair fibre. Following the telogen phase, the next anagen phase begins, and the old hair is dislodged and falls out to make room for a new hair to begin growing in its place.
DHT is found in several tissues in the body including the prostate gland and skin.
Male pattern hair loss occurs in men who are genetically predisposed to be more sensitive to the effects of DHT. Researchers now believe that the condition can be inherited from either side of the family.
Male pattern hair loss affects nearly all men at some point in their lives. It affects different populations at different rates, probably because of genetics.

Alopecia Areata

Alopecia areata, also known as spot baldness, is a condition in which hair is lost from some or all areas of the body. Often it results in a few bald spots on the scalp, each about the size of a coin. Psychological stress may result. People are generally otherwise healthy. In a few, all the hair on the scalp or all body hair is lost and loss can be permanent.

Treatment may address any underlying conditions and includes topical scalp medication. Alopecia areata is believed to be an autoimmune disease. Risk factors include a family history of the condition.

Frequently asked questions

The most common pattern is one or more well-defined spots of hair loss on the scalp. If alopecia occurs in an ophiasis pattern (hair loss involving the temporal and posterior scalp) or if large areas of the scalp are involved for long periods of time, the prognosis is worse. A more generalized form of hair loss is referred to as diffuse alopecia areata where there is widespread dramatic thinning of the scalp hair. Occasionally, all of the scalp hair is entirely lost, a condition referred to as alopecia totalis. Less frequently, the loss of all of the hairs on the entire body, called alopecia universalis, occurs
Alopecia areata tends to occur most often in adults 30 to 60 years of age. However, it can also affect older individuals and, rarely, young children. Alopecia areata is not contagious. It should be distinguished from hair shedding that may occur following the discontinuation of hormonal estrogen and progesterone therapies for birth control or the hair shedding associated with the end of pregnancy. There are a number of treatable conditions that could be confused with alopecia areata.
The characteristic finding of alopecia areata is one or more well-circumscribed areas of otherwise normal, hairless skin in hair-bearing areas. Occasionally, it may be necessary to biopsy the scalp to confirm the diagnosis. Other findings that may be helpful are the appearance of short hairs that presumably represent fractured hairs, short thin hairs, and gray hair growing in a bald area. Other causes of hair loss are generally excluded from the consideration by history and clinical evaluation