Introduction to hair loss
Hair loss is one of the most widespread imperfections in both men and women worldwide. It affects more than 80% of men and around 40% of women, and can have different causes and origins.
Classifying all forms of hair loss, baldness and alopecia is always very complex and reductive. The world of trichology is still being studied by national and international experts, and there are still many aspects to be clarified.
It is appropriate to start by introducing a few fundamental concepts and then analyse each condition and pathology in depth:
- The term defluvium, from the Latin defluvium, refers to abnormal hair loss in terms of quality rather than quantity. This hair loss can lead to baldness (irreversible lack of hair) or hypotrichia (lack of hair) due to the loss of hair follicles.
- The term defluvium, from the Latin defluvium, refers to abnormal hair loss in terms of quality rather than quantity.
- The term effluvium, or effluvium, refers to cases in which hair loss occurs in very high percentages and in a homogeneous and synchronous manner over the entire scalp. The prognosis in these cases is not negative.
- By alopecia we mean the lack or total absence of hair or hair. This category includes baldness and hypotrichia. Alopecia can be temporary, i.e. transient and reversible, when there is only a momentary inhibition of the hair papilla, or definitive, when the follicle disappears altogether.
In order to fully understand the processes that regulate the birth, growth and fall of hair, reference should be made to the life cycle of the hair.
The hair’s life cycle;
The hair lifecycle – physiological hair loss
The hair follicle is the only structure in the human organism that carries out a cyclical activity that lasts throughout an individual’s life. The hair cycle begins during gestation, around the 32nd week of pregnancy.
The first cycle ends in utero and the second after birth. This first hair is called lanugo. They are short and thin. As time goes by, the hair grows back longer and stronger and continues its life cycle.
Although the mechanisms regulating the process of hair growth and loss have been extensively studied today, there is still much to investigate.
The hair cycle can be divided into different phases. Generally only three are indicated: the anagen, catagen and telogen phases. However, experts now identify six, as teloptosis, exogen and kenogen are added to the three mentioned above.
- Anagen phase: The anagen phase is when the hair grows. The follicle sinks into the dermis and gives rise to the hair shaft. This phase lasts approximately 6 years and is divided into 6 sub-phases. During the first 4 sub-phases, there is strong mitotic activity, with the keratinocytes multiplying and pushing down into the dermis to their maximum depth. During the fifth sub-phase, mitotic activity gradually decreases and during the sixth sub-phase it is almost completely reduced. The objective at this point is to maintain a condition of equilibrium between the keratinocytes in the reproduction phase and the keratinocytes that make up the stem.
- Catagen phase: The catagen phase sees a complete cessation of mitotic activity. It represents the involution phase of the hair follicle as all the cells are not replaced. The hair’s inner epithelial sheath begins to disappear and the outer sheath becomes thinner. This phase lasts approximately 20 days.
- Telogen phase: The telogen phase is the follicle’s mitotic resting phase. The inner epithelial sheath has completely disappeared and the bulb adheres to the follicle thanks to the presence of adhesion proteins. This phase lasts about three months and, in the absence of any particular scalp pathology, there will be a hair to replace the one that is falling out. In reality, the telogen phase is always characterised by weak metabolic activity that sees a multiplication of the cells of the matrix.
For this reason, the final telogen phase is divided into:
- Exogen phase: The exogen phase sees the hair detaching from the follicular sheaths. The exogen ends when the hair shaft is free of the follicle.
The exogen phase sees the hair detaching from the follicular sheaths.
- Teloptosis:During teloptosis there is detachment of the hair shaft from the follicle. The hair falls out because there is no longer any cohesion between the hair shaft and sheaths.
- Kenogen: This is the true resting phase of the hair follicle. For a short period of time, before a new anagen phase begins, the follicle remains empty. It is here that new hair growth will take place.
In the event of pathologies or abnormalities, the life cycle of the hair is compromised. The hair is reborn thinner and weaker, until, in the most severe cases, mitotic activity ceases completely. This is referred to as the miniaturisation process.
Androgenetic alopecia (common baldness)
By the term androgenetic alopecia we refer to the form of baldness due to the action of the enzyme 5-alpha-reductase type 2 on hair follicles. The enzyme is responsible for the transformation of testosterone into dihydrotestosterone (DHT), an androgenic hormone which, in predisposed individuals, attacks the follicles causing their miniaturisation and consequent hair loss.
This form of alopecia is also known as common baldness, as it affects both men and women, albeit in different proportions. It occurs in approximately 70% of men and 40% of women. It is a form of non-reversible baldness, although there are pharmacological therapies that can inhibit the action of the 5-alpha-reductase enzyme and temporarily control the hair loss.
For more information: Common Baldness
Telogen effluvium – physiological and chronic hair loss.
Telogen effluvium, also known as TE, is one of the main causes of hair loss. It is an often ignored condition due to its heterogeneity. Headington distinguished five different types of telogen effluvium:
- Release of anagen immediately
- Delayed anagen shedding
- Short anagen syndrome
- Immediate telogen release
- Delayed telogen shedding
All these variants occur through temporary excessive hair loss and a sensation of paresthesia on the scalp (trichodynia). The follicle enters the telogen phase prematurely, and the number of hairs falling out is higher than the number of hairs growing.
The most acute form of telogen effluvium is usually caused by childbirth or heparinoid treatment. Other causes include situations of high physical and emotional stress.
As a rule, the hair loss does not lead to the formation of completely hairless patches, but to diffuse thinning, especially if the condition lasts for some time. The course of the disease is variable and usually even the acute form resolves spontaneously within about two months.
How is telogen effluvium diagnosed? What is the treatment?
Telogen effluvium is not difficult to diagnose. It is generally sufficient to analyse the clinical history and observe the patient’s stage of thinning. The main difficulty lies in distinguishing between telogen effluvium and the first stages of hair loss, which we will discuss later.
The pull test can be useful here. Patients suffering from telogen effluvium lose terminal hair and only a small amount of miniaturized hair. Conversely, those suffering from baldness have many miniaturized stems.
In order to understand how to intervene, it is advisable to analyse the causes and act by promoting the general well-being of the body.
For more information: Telogen Effluvium.
Anagen effluvium – widespread and rapid hair loss.
Anagen effluvium is a form of alopecia that manifests itself as diffuse and rapid hair loss, evenly affecting the entire scalp. It affects follicles in the anagen phase, i.e. in the active growth phase. Generally, hair follicles in the anagen phase account for up to 90% of all follicles and are evenly distributed across the scalp.
Consequently, anagen effluvium is a form of hair loss that can be very severe, affecting almost all hair follicles, except for around 10%.
What are the causes of anagen effluvium?
The main causes of the condition include:
- Disorders in the metabolism of matrix cells that cause an interruption in their reproductive activity
- Metabolic changes in the cells of the hair follicle lead to an interruption in the production of hair fibre. The hair shaft changes in shape and has a narrower zone in which the structure is weak. This is why hair breaks easily
- Drugs or substances capable of modifying the metabolism of hair follicle cells
- Chemo drugs inhibit cell metabolism;
- Radiation, such as x-rays and gamma rays
- In rare cases severe anaemia, or deficiencies of copper, zinc or biotin can slow down cell metabolism
- Autoimmune forms due to genetic predisposition.
Alopecia Areata – patchy hair loss
A form of alopecia, probably due to particular genetic characteristics, is alopecia areata. Experts have not yet identified with absolute certainty the causes of the condition. It occurs regardless of age, so much so that it generally affects children from 0 to 5 years of age in a temporary form.
It is an ever-changing condition that can, in some cases, become almost stable or, in others, extend to the entire scalp (total alopecia), or to the hairs of the whole body (universal alopecia).
For more information: Alopecia Areata.
Camouflage systems against hair loss
Among the most popular hair loss camouflage products:
- Toppik: keratin microfibres which, after being electrostatically charged, anchor themselves to the hair. The hair will appear thicker and the skin will no longer be so visible through the hair
- Couvré: fluid coloured cream to be applied directly to the scalp, not to the lengths, using a sponge. It is available in various colours such as black, dark brown, medium brown, light brown, blonde and grey.
- DermMatch: a cosmetic product similar to a foundation capable of anchoring itself to the hair, making the scalp thicker.
For more information on camouflage: Toppik.
