Alopecia is the medical term for hair loss and it appears in a variety of types, according to its pattern, severity and duration. The medical term “Alopecia” originates from an ancient Greek word that means “fox”. Alopecia is usually manifested in the following forms:
- Hair falls and regrows in a repeated circle
- Hair falls and then regrows with alterations in the hair shaft
- Hair falls from different areas of the scalp and then regrows without any further manifestation of hair loss
The 2 basic categories of alopecia are scarring and not scarring alopecia.
Non Scarring Alopecia
- Androgenetic Alopecia.
- Physiological alopecia.
- Alopecia Areata.
- Telogen Effluvium.
- Anagen Effluvium.
- Alopecia due to Harming Factors.
Androgenetic Alopecia
It is the most common type of male and sometimes female hair loss. Thinning appears in the front, upper and top area of the scalp. The back and sides of the scalp maintain the highest percent of their hair.
It is worth mentioning that at an initial stage, appearance of thinning is due to hair miniaturization (progressive shrink of hair).
Heredity, along with androgens and aging, are the 3 factors responsible for Androgenetic Alopecia.
The most effective solution for androgenetic alopecia is hair transplantation procedure.
Physiological alopecia
Normally, we lose 50-100 hairs a day, numbers that are no cause of concern. This can be attributed to the fact that hair growth cycle is asynchronous and every day some of the hairs at Telogen Phase are ready to fall.
A common type of physiological alopecia is seasonal hair loss and it can be mainly observed in autumn and spring, as the result of the reaction of hair follicles to seasonal changes.
Alopecia Areata
Alopecia Areata is clinically described as appearance of completely bald areas of the scalp, while skin is preserved intact.
Hairs round the bald areas are of small diameter near the root and of bigger at the edge of the shaft (Exclamation point hairs).
Hair loss tends to be rapid in alopecia areata. In some cases, hair loss appears progressively at irregular intervals. Alopecia areata can affect both males and females, and even children.
There’s a 1% possibility for someone to be affected by Alopecia Areata. Approximately 25% of alopecia areata cases are due to heredity.
Almost 20% of alopecia areata cases reappear or even end up with permanent alopecia.
Factors of great importance for the beginning and progress of alopecia areata can be genetic, psychological or immunological.
The clinical description of alopecia areata includes:
1)Simple patterns.
2) Extensive patterns.
3) Peripheral hair loss, involving loss of hair on the cervical, occipital and temporal areas.
4) Alopecia Totalis, involving loss of hair, eyebrows and eyelashes.
5) Alopecia Universalis, involving loss of all hairs of the body.
6) Diffuse Alopecia Areata.
Causes of Alopecia Areata
Alopecia Areata is an auto-immune disease; the organism΄s immune system recognizes hair follicles as a foreign body and attacks them.
The organism΄s defense system, with the help of T-lymphocytes, forces hair follicles to enter Telogen Phase-the last phase in hair life cycle.
At the end of Telogen Phase, which lasts 3-4 months, hair falls.
Although the above is considered to be the most prevalent explanation for alopecia areata, genetic predisposition can be another explanation for its appearance.
In some cases, no treatment is needed for alopecia areata and hair grows back quite soon (although white in some rare cases).
Treatment of alopecia areata can be topical or systematic. Alopecia Areata is usually dermatologically treated with cortisone.
The effectiveness of each therapy depends on the pattern, extent and periodicity of the phenomenon.
Telogen effluvium
Telogen Effluvium is a form of Alopecia characterized by diffuse hair shedding. It can be caused when hair growth cycle is suddenly interrupted:
Approximately 80% of hair is in the Anagen Phase, but due to a particular event it may rapidly enter the Telogen Phase, which is the last phase in hair growth cycle.
Hair remains in this phase for 3-4 months and then falls, as the growing of new hair sets the older to fall. This is the period when diffuse hair loss can be observed.
Telogen Effluvium can affect hairs all over the body, although the scalp is most usually affected.
In fact, we have all experienced Telogen Effluvium during the first months of our life.
There are 3 types of Telogen Effluvium:
• Acute, when hair loss occurs rapidly.
• Sub acute, when hair loss insists for several months.
• Chronic, when hair loss tends to be repeated and last more than 6 months each time.
The interruption of normal hair growth cycle can occur as a result of metabolic stress (chemotherapy, pregnancy, puberty, surgery, severe stress and chronic illnesses), emotional trauma or systematic attack.
Hair loss appears 3 months after the experience of the intense incident and it may involve even 50% of hair in rare cases.
Definition of Telogen Effluvium causes is quite difficult in some cases, as there is a period of 3 to 4 months between the first influence of the cause and the expression of its symptoms.
The most common causes of Telogen Effluvium are:
• Diseases, severe physical or psychological traumas.
• Menopause.
• Pregnancy&birth.
• Severediets.
• Postoperativestress.
• Anaemia.
• Thyroiddisorders.
• Chronic illnesses / for instance: lupus erythematosus, liver or kidney problems.
• Heavy metal poisoning(e.g. lead, mercury, cadmium).
• Immunizations.
• Certain medicines / for instance non steroid anti-inflammatories, retinoids, anticoagulants.
• Contraceptive pills, at the beginning or end of use.
Birth
Some women experience Telogen Effluvium 3 months after birth, due to the alterations of hormonal levels.
High levels of estrogens and progesterone during pregnancy, maintain a higher than normal percentage of hair in the Anagen Phase.
But the upcoming recession in hormonal levels forces hair to enter Telogen Phase and then increased hair loss can be observed.
But It is a reversible phenomenon that occurs only to be restored 9 months after birth.
Anagen effluvium
Anagen Effluvium can be experienced as sudden hair loss due to chemical or toxic effect or even radiation-e.g. chemotherapy.
Hair loss is observed 1 to 3 weeks after the exposure to one of the previous factors.
In most cases, hair regrows when the cause of Anagen Effluvium ceases. For this reason, hair transplantation is not proposed.
- Chemotherapy
Rapid, massive hair loss is one of the side effects of chemotherapy and usually influences almost 90% of hair. In the majority of cases, hair regrows after the end of the medical treatments.
- Radiation threatment
Hair loss appears only on the affected areas of the scalp. Hair loss due to low frequency radiation may be reversible, causing only changes in the quality of hair.
Alopecia due to harming factors
1. diffuse hair loss due to hormonal disorders (hypothyroidism, hyperthyroidism, diabetes, pregnancy, contraceptive pills, menopause).
2. diffuse alopecia due to medicines or chemicals (antithyroid, anticoagulant, overdose of vitamin Α, boric acid, thallium salts, insecticide products, other chemical compounds).
3. diffuse alopecia due to malnutrition or metabolic disorders (protein, iron, zinc or essential fatty acids deficiency, etc).
Scarring alopecia
Clinical description: damaged hair follicles, skin scarring and permanent alopecia.
In many cases it is manifested in a gentle form, without any symptoms and it progresses gradually.
Some experience intense inflammation-usually under the skin- that progresses rapidly and is usually supplemented by pain, itching and a sense of heat.
There are 2 basic scarring alopecia categories, primary and secondary.
In primary scarring alopecia, inflammation has an impact only on hair follicles, while in secondary scarring alopecia the inflammation is symptomatic or caused by external factors (burns, infections or radiation).
Causes of scarring alopecia may be:
- Growth disorders and hereditary diseases (skin aplasia, for example).
- Inflammatory infections.
- Skin neoplasia.
- Skin diseases, as: ringworm, scleroderma, sarcoidosis, systematic lupus erythematodis.
- Mechanical traumas, burns, x-ray dermatitis.
Traumatic Alopecia
Trichotillomania is a form of self-enforced scarring alopecia, in which the affected person develops the need to pull and uproot his own hair, usually by rolling his hair round his finger.
If this need is treated, then hair transplantation can be a very good option.
Traction Alopecia is caused due to repeated pulling of hair and usually affects women who fix their hair tightly for a long period.
The repeated traction can cause irreversible damage, due to the inflammation of hair follicles. Then hair does not regrow. In this case, hair transplantation can be a good solution.
In some cases, alopecia may occur as a result of a trauma (burn, damage by accident etc) which can destroy even the deepest layers of skin that bear hair follicles.
Hair transplantation can be the appropriate solution in many of these cases.
Links:
www.naaf.org NATIONAL ALOPECIA AREATA FOUNDATION
www.aad.org AMERICAN ACADEMY OF DERMATOLOGY
www.carfintl.org CICATRICIAL ALOPECIA RESEARCH FOUNDATION