Reactional hair loss and androgenetic alopecia: not to be confused for one another
Reactional hair loss
Also known as occasional hair loss or, in medical language, acute telogen effluvium. There are different types of reactional hair loss which can occur at any time depending on fatigue, stress, season, climate, eating habits or hormonal balance. This type of hair loss is sudden, some people can even have hair falling out by the handful, and lasts less than 6 months. Alopecia is defined as diffuse, i.e., evenly distributed throughout the head. When the triggering factor has been identified and eliminated, improvement is always seen, although it can take between 12 and 18 months for the hair to return to its original state.Androgenetic alopecia
In this case, the mechanism is hormonal and hereditary. It is not uncommon for this form of hair loss to lead to baldness in men. It is even the most common form of alopecia in men: 70% to 80% are affected in their lifetime*. Its symptoms: progressive hair loss as the years go by, characterized by thin hair and localized hair loss on the top of the head. Note that female androgenetic alopecia is not uncommon either. In this case, it rarely leads to baldness, but it is responsible for a, sometimes significant, loss of hair volume and density.Chronic telogen effluvium
This other type of chronic hair loss fluctuates and lasts for more than 6 months. This type of hair loss generally occurs in women between 30 and 50 years old with, originally, healthy, thick and shiny hair. Among its causes: thyroid disorders, anorexia, iron deficiency and certain medications. Unlike androgenetic alopecia, chronic hair loss does not result in permanent or irreversible hair loss. Symptoms to be aware of: diffuse, somewhat light hair loss, but which lasts for more than 6 months and which can lead to a progressive reduction in hair mass.Anagen Effluvium
This type of hair loss corresponds to a sudden shedding of the hair fiber during its growth phase after multiplication of the cells of the hair follicle is stopped. Its onset is quick, on the order of a few days to a few weeks. It appears as diffuse alopecia, which can affect the entire scalp. This type of hair loss is mainly observed following cancer chemotherapy or exposure of the head and neck to radiotherapy. It can also affect the eyebrows and body hair.Alopecia, symptoms and triggers
This chronic and diffuse type of hair loss appears gradually. It usually begins just after puberty and develops gradually to settle in between the ages of 30 and 40. The symptoms of this type of alopecia: light but progressive hair loss on the top of the head, dull and often greasy hair. In some cases, we see hair loss with itchy scalp.
Hair loss: the symptoms that should alert you
- A change in diet? This can have a direct impact on the hair. Vitamin and mineral deficiencies can be responsible for hair loss.
- Hair falling out in autumn like the leaves on the trees? This is seasonal hair loss, caused by hormonal variations and a lack of light at that time of year.
- Hair falling out by the handful after childbirth? It is probably post-partum hair loss, due to the hormonal changes observed during this period. One third to one half of women are affected**.
- Hormonal disorders? It is not uncommon for an excess (or lack) of hormones to cause various imbalances in the body, including hair loss. The phenomenon is identical in the case of metabolic disorders, such as iron deficiencies, for example.
* Source: Blume-Peytavi et al., 2011; Norwood, 1975
**Source: Grover and Khurana, 2013