Hair loss is often a source of anxiety and although more common among men, it can also affect some women. It can be caused by a multitude of factors. To treat it effectively, early intervention is essential.
Hair constantly renews itself and it is perfectly normal to lose a little each day, and more during spring or autumn. It is also natural for hair to get lighter as we age: progressively, new hairs become finer than the previous ones.
Hair loss becomes a problem when more than about a hundred hairs are lost each day. In the long term, this leads to the hair thinning or disappearing completely, which causes a change in physical appearance that is sometimes difficult to live with.
- The different types of hair loss
The most common cause of hair loss is androgenic alopecia, meaning its origin is both hormonal and genetic. It is much more common among men – 1 in 2 men is affected at age 50 – and it can sometimes start as early as puberty. The hair starts to thin above the temples and forehead first. In women, the hair becomes thinner on the top of the scalp. Androgenic alopecia is due to increased sensitivity of the hair follicles to androgens. These male hormones accelerate the hair’s life cycle. Yet the number of cycles of each hair follicle is predetermined: in one lifetime, it produces between 24 and 25 hairs. When there is a hypersensitivity to androgens, the hair follicles reach their hair production limit more quickly, and hair gradually becomes thinner. Even though androgenic alopecia is often hereditary, its genetic mechanisms are complex and it remains difficult to predict.
Patchy alopecia on a normal scalp
In this case, there is hair thinning or baldness in certain areas of the scalp, yet the rest of the hair is normal and the scalp is healthy. Alopecia areata (an autoimmune disease which causes total hair loss on small areas of the scalp) and trichotillomania (a nervous tic which consists in pulling out or twisting one’s hair) are the two main causes of this type of alopecia.
Patchy alopecia on a damaged scalp
Some diseases or skin infections (lupus, psoriasis, lichen planus, etc.), as well as scars due to blows or burns, can lead to the destruction of the hair follicles in the affected areas. These are then completely bald. Ringworm, a fungal infection of the scalp, also produces patchy alopecia. It is particularly common in children. In most cases the hair grows back once the infection has cleared.
- A multitude of factorsAlthough genetic predisposition plays a major role in alopecia, other elements can also contribute to it or aggravate it:
- Mechanical stressors on the hair: overly vigorous hair brushing, tight hairdos, etc.
- Tobacco: this causes hair to age prematurely. Smoking more than 20 cigarettes a day doubles the risk of alopecia.
- Certain nutritional deficiencies: lack of iron, vitamins, sulphur-containing amino acids, etc.
- Certain drug therapies, including chemotherapy.
- Other environmental or personal factors: exposure to UV rays and sunlight, pollutants, emotional stress, etc.
- Treating hair loss
Taking action as early as possible is essential to avoid baldness: treatments are much more effective if the hair has not completely disappeared. See your skin specialist as soon as you notice that your hair has started thinning. She/he will help you determine the cause of your hair loss and decide on an appropriate treatment: treatments applied locally, oral medication, or even surgery in the most severe cases.
Regular appointments will then enable you to track the progress of your treatment and how well you are tolerating any medications. Hair loss usually stops after 2 to 3 months of treatment and new hairs start to grow back a little later. Regrowth stabilises at its maximum level after another few months. Nevertheless, there is currently no definitive treatment for androgenic alopecia: prescriptions must be renewed in order to maintain any results achieved in the long term.
Whether used alone or in association with drug therapy, skin treatments and food supplements also contribute to treating hair loss, so you should discuss your options with your chemist.
CEDEF. Troubles des phanères : alopécie. Item 288. Ann Dermatol Vénéreol 2008; 135 S, F200-F204.
P. Reygagne, B. Matard. Alopécies. In Thérapeutiques dermatologique, L. Dubertret, Médecines-Sciences, Flammarion, Paris, 2001.p 31.
S. Boulinguez. Journées dermatologiques de Paris. Cheveu, vieillissement et environnement. De nouvelles données. Ann Dermatol Vénéréol 2009 ; 136 :S 21