Alopecia: all about hair loss
What is alopecia?
Alopecia is a medical term for hair loss leaving the skin partially or completely naked. Baldness, or androgenetic alopecia, is the most common form of alopecia. It mainly affects men. Hair loss is a natural phenomenon strongly determined by heredity. Other forms of alopecia can reveal a health problem or be caused by taking medication, for example. nd
Some people choose to take treatments to stimulate regrowth or limit falling. Hair being culturally associated with seductive power, health and vitality, the treatment of alopecia arouses great interest. However, you should know that the result is not always satisfactory. Hair transplantation may then be the last resort.
Types of alopecia
Here are the main forms of alopecia and their causes. Even though alopecia mainly affects the hair, it can occur on any hairy area of the body.
Baldness and androgenetic alopecia
About a third of Caucasian men have baldness by the age of 30, half around the age of 50 and around 80% from the age of 70.3 In men, baldness is characterized by the progressive decline in edge of the hair, at the top of the forehead. Sometimes it occurs more at the top of the head. Baldness can start at the end of adolescence;
Women are less likely to suffer from baldness. At the age of 30, it affects 2% to 5% of women, and almost 40% at the age of 70 years4. Female pattern baldness looks different: the whole of the hair from the top of the head is becoming more and more sparse. Although it is often reported that hair loss tends to worsen from menopause, this has not been evident in the epidemiological studies conducted to date.
Several studies are underway 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 speeds up the hair life cycle. Over time, these become increasingly thin and short. The hair follicles shrink and then stop being active. It also seems that certain types of hair are more influenced by the level of testosterone. The causes of female pattern baldness have been much less studied. Women also produce androgens, but in very small quantities. In some women, baldness could be linked to a higher level of androgens than the average but the main cause is heredity (history of baldness in the mother, a sister …).
Alopecia can be caused by a permanent lesion of the scalp due to a disease or infection of the skin (lupus, psoriasis, lichen planus, etc.). The inflammatory reactions that occur in the skin can destroy the hair follicles. Ringworm, a fungal infection of the scalp, is the most common cause of alopecia in children. In their case, however, there is regrowth in most cases;
Ringworm, a fungal infection of the scalp, is the most common cause of alopecia in children. In their case, however, there is regrowth in most cases;
Alopecia areata, or plaque alopecia, is an autoimmune disease. It can be recognized by the complete loss of hair or hairs on small areas of skin. Sometimes there is regrowth, but a relapse is always possible months or years later. Universal alopecia areata (loss of all body hair) is very rare. For more information, see our Pelade sheet;
It is a sudden and temporary loss of hair, following a physical or emotional shock, pregnancy, surgery, significant weight loss, high fever, etc. Up to 30% of the hair prematurely enters the resting phase, then falls out. Once the stress has passed, the hair follicles return to the active phase. It may take a few months, however;
Very rare, it can notably be due to the absence of hair roots or to an anomaly in the hair shaft. Mutations in the P2RY5 gene are thought to be responsible for one of these hereditary forms called hypotrichosis simplex, which begins in childhood in both sexes. This gene is believed to participate in the formation of a receptor which plays a role in hair growth;
Médicaments, chimiothérapie, etc.
Différentes situations peuvent déclencher une perte de cheveux. Par exemple, des carences nutritionnelles, un déséquilibre du système hormonal, des traitements de chimiothérapie ou de radiothérapie pour traiter un cancer, des médicaments (par exemple, la warfarine, un anticoagulant, ou le lithium, utilisé dans le traitement des troubles bipolaires).
Quand consulter ?
Si vos cheveux se mettent à tomber par poignées ou par plaques, sans raison apparente ;
Si vous désirez expérimenter un traitement dans le but de masquer une calvitie.
L’opinion de notre médecin
Dans le cadre de sa démarche de qualité, Passeportsanté.net vous propose de découvrir l’opinion d’un professionnel de la santé. Le Dr Dominic Larose, urgentologue , vous donne son avis sur l’alopécie :
La plupart des cas de perte de cheveux diffuse que j’ai pu voir dans ma pratique n’étaient simplement que des cas d’effluvium télogène. Donc, soyez patient et consolez-vous en vous disant qu’en fait, les cheveux qui tombent sont en train de repousser à partir du follicule pileux correspondant.
Par ailleurs, peu de gens sont enclins, en cas de calvitie, à entreprendre un traitement quotidien de durée indéterminée. La plupart (comme moi!) acceptent que la calvitie soit en grande partie inéluctable. Comme la presbytie, le grisonnement et le reste…
Pour les gens qui y tiennent vraiment, la chirurgie est une option raisonnable.
Dr Dominic Larose, M.D.