Alopecia is a medical term for hair loss leaving partially or completely bare skin. Baldness or androgenetic alopecia is the most common form of hair loss. It affects mostly men. It is a natural phenomenon strongly determined by heredity. Other forms of alopecia can result from an health problem or be caused by medications, for example.
In Greek, Alopex means “fox.” Hence alopecia recalls the important fur loss suffered by the fox every year in early Spring.
Some people choose to undertake treatment to stimulate regrowth or limit hair fall. The hair is culturally associated with the power of seduction, health and vitality, so that treatment of alopecia meets a great interest. However, you should know that the result is not always satisfactory. Hair transplantation may then be the last resort.
Types of Alopecia
The main forms of alopecia and their causes are listed below. Although alopecia affects mainly the hair, it can occur on any hair-bearing area of the body.
Baldness or androgenetic alopecia. About a third of Caucasian men have some baldness at the age of 30 years, half at the age of 50 years and about 80% from 70 years old. For men baldness is characterized by progressive decline of the hairline. Sometimes it occurs rather at the top of the head. Baldness can begin as early as the late teens.
Women are less likely to suffer from baldness. At age 30, it affects 2% to 5% of women and almost 40% at the age of 70 years old. Female baldness looks different: all the hair from the top of the skull becomes increasingly sparse. Although it is often reported that hair loss tends to increase with menopause, it is not apparent in epidemiological studies.
Several studies are under way to better understand the causes of baldness. Heredity seems to have a major influence. In men, baldness is influenced by male sex hormones (androgens) such as testosterone. Testosterone accelerates the life cycle of hair. Over time, they become thinner and shorter. Hair follicles shrink and cease to be active. It also appears that certain types of hair are more influenced by testosterone. The causes of baldness in women have been much less studied. Women also produce androgens, but in very small quantities. In some women, baldness could be linked to a higher androgen than average but the main cause is heredity (history of baldness in a mother, sister …).
Scarring alopecia. Alopecia can be caused by a permanent injury of the scalp due to an illness or infection of the skin (lupus, psoriasis, lichen planus, etc..). Inflammatory reactions that occur in the skin can destroy hair follicles. Ringworm, a fungal infection of the scalp is the most common cause of alopecia in children. However, among them there is regrowth in most cases.
Ringworm, a fungal infection of the scalp is the most common cause of alopecia in children causes. However, among them there is regrowth in most cases. Alopecia areata, or sclerosis alopecia is an autoimmune disease. It is recognizable bythe complete loss of hair on small areas of skin. There is sometimes regrowth, but a relapse is always possible months or years later. Universal alopecia (loss of all body hair) is very rare.
Telogen effluvium is a sudden and temporary hair loss as a result of a physical or emotional shock, pregnancy, surgery, a significant weight loss, high fever, etc.. Up to 30% of hair fall prematurely into a resting phase and then fall. Once the stress is passed, the hair follicles go back into active phase. However, this can take a few months.
Congenital alopecia is very rare, it can especially be attributed to the lack of hair roots or an abnormality of the hair shaft. Mutations in the gene P2RY5 are responsible for any of these inherited forms called hypotrichosis simplex, which begins in childhood in both sexes. This gene participate in the formation of a receptor that plays a role in hair growth;
Drugs, chemotherapy, etc. Different situations can trigger hair loss. For example, nutritional deficiencies, hormonal imbalance system, chemotherapy or radiation therapy for cancer, drugs (eg, warfarin, an anticoagulant, or lithium, used to treat bipolar disorder).