Alopecia: Types, Hair Cycle, Causes, Symptoms & Treatment

By March 31, 2017 No Comments
Alopecia: Types, Hair Cycle, Causes, Symptoms & Treatment


Alopecia is a Greek term derived from the word alopecia which means hair fall. It may be defined as a set of disorders involving the state of lacking hair in places where it would grow normally, especially in the head. Average shedding of hair in normal person is about 50 to 100 telogen hairs in a day. This shedding of hair is a normal physiological process. Shedding of hairs more than 100 telogen hair per day is alopecia. Hair fall impacts the appearance of the person. It also affects confidence and youthfulness of a person.

Hair cycle

To know about the alopecia it is important to know about the hair cycle. Hair cycle consists of three phases.

  • Anagen

It is the first and active phase of the hair cycle. It is also the longest phase of the hair cycle and lasts for about 2 to 6 years. In this phase production of hair and its elongation takes place.

  • Catagen

It lasts for about  2 to 3 weeks. It begins when the production of melanin from melanocytes ate stopped.  In this phase cell division in the hair matrix stops and the base of hair is keratinized to form a club hair. The hair shrinks and separate from the follicle after keratinization and pushes the club hair forward.

  • Telogen

It lasts for about 2 to 3 months. Dermal papillae form a ball close to the tip of the hair follicle and the new hair starts growing from the base and pushes the older hair out. Normal telogen hair fall is 50 to 100 per day.

Causes of Alopecia

Causes of alopecia or hair fall range from genetics to drugs. Some of the causes of alopecia are listed below

  1. Emotional stress such as psychiatric diseases, a death of family members, unemployment, marital difficulties.
  2. Physical stress such as  anaemia, surgery, insomnia
  3. Hormonal causes like intake of oral contraceptives and testosterone containing hormonal supplement, menopause, insufficient hormone replacement.
  4. Rapid weight loss or gain, vegetarian, prolonged fasting, low protein intake.
  5. Heredity
  6. Autoimmune disease
  7. Ageing
  8. Malnutrition
  9. Psoriasis and dermatitis
  10. Fungal infection
  11. Sarcoidosis
  12. Iron deficiency
  13. Radiation and chemotherapy
  14. Hairstyling

These factors may cause alopecia by any of the following mechanisms such as reduction of function of the hair follicle, reduction in function of hair bulbs, reduction in physiological function of the scalp and impairment of the circulation in the subcutaneous tissue of the scalp.

Types of Alopecia

According to the underlying  causes and the pattern of hair fall, Alopecia is divided into following types

  • Androgenic alopecia

It is the most common cause of progressive alopecia in the world. Androgenic alopecia is also known as patterned alopecia or male pattern baldness or female pattern baldness. It affects about 50% of the males above the age of 50 and 50% of females above the age of 65. It can be caused by both genetic and hormonal factors. The hormone dihydrotestosterone is responsible for androgenic alopecia. In males hair loss recedes the frontal hairline and the loss of hair occurs from the top and the front of the head while in females hair loss occurs from the crown of the scalp preserving the frontal hairline. Hairs on the affected part are smaller in diameter and shorter in length in comparison to the hairs of the unaffected part.

  • Alopecia areata

It is also known as spot baldness. It is the third most commonly found type of alopecia. Alopecia areata is an autoimmune disorder causing loss of hair on all parts of the body. It occurs irrespective of age, sex, and age and often appears during childhood. Some people may complain of burning or itching sensation in the affected area while others may have no such symptoms. It usually starts as patches of hair loss. Patches may be single, double or multiple.

  • Scarring alopecia

Scarring alopecia is also known as cicatricial alopecia is caused by the inflammatory process. The inflammatory process leads to permanent damage to the hair follicles. The inflammatory process can be initiated by burns, bacterial infection, ringworm, injury to scalp, etc. Scarring alopecia is a group of rare disorders which causes hair loss along with scarring. It is diagnosed in about 3% of all cases of alopecia. Initially, it starts as small patches of hair loss and expands with time. It may be gradual or rapidly progressive, asymptomatic or associated with itching, burning, and pain. The edges of the scarring alopecia are ragged which also helps in differentiating it from the alopecia areata.

  • Telogen effluvium  and  chronic  telogen effluvium

It is the second most common cause of the hair loss. It is caused by the early entry if the hair into the resting phase of the hair cycle called telogen phase. It can be triggered by the extreme weight loss, thyroid disorders, surgery, emotional stress, physical trauma, childbirth, menopause, etc. It is a form of temporary hair loss and it lasts for 2 to 4 months only. Chronic telogen effluvium is another condition which is triggered by the same factors as telogen effluvium, but it lasts for more than 6 months. The scalp shows the signs of hair thinning, but is not associated with the loss of hair follicles.

  • Trichotillomania

It is a condition characterized by the person’s compulsion to pull his or her own hair out. It is also known as a hair-pulling disorder. People suffering from this disorder can pull the hair of any part of the body. This condition runs in family and is often noticed first in childhood. It occurs more commonly in people with the obsessive-compulsive disorder and can be triggered by anxiety.

  • Traction alopecia

It is related to hair styling and often occurs in people with a hairstyle that requires pulling and tying of hair tightly. The hairs are so tightly pulled or tied that even hair roots are pulled from the scalp.

Symptoms  of alopecia

The symptoms of alopecia vary from person to person and are dependent on the underlying cause of alopecia. Some of the symptoms of alopecia according to the types of the alopecia are listed below

  • Stress-related alopecia
    Gradual shedding of hair and hair fall on gentle pulling of the hair.
  • Male pattern baldness
    Hair fall recedes the frontal hairline. Hair fall occurs from the top and front of the head.
  • Female pattern baldness
    Hair loss occurs from the crown of the scalp and does not recede the frontal hairline.

  • Alopecia areata
    Round or oval patches of hair loss
    Patches may be single, double or multiple
    Rapid hair loss
    Fingernails and toenails may show pitting

  • Fungal infection
    Patches of hair loss along with the presence of the black dots on the patches
    Itching and burning sensation over the affected area.
    Redness and scaling may be present.

Treatment of alopecia

The majority of the cases of the alopecia does not need medical treatment but most people opt for the treatment of hair loss due to the cosmetic reasons.

  • Medical treatment
    Medicines are minoxidil and finasteride is widely used for the treatment of alopecia.
  • Minoxidil
    Minoxidil is available in the market as a lotion with 2% and 5% versions. It unclear how it works till now. It may take several months to show its effects. Hair fall may continue after stopping the treatment with the minoxidil.
  • Finasteride
    Finasteride is a prescription only drug (currently prescribed for males only) which prevents the conversion of the testosterone into the dihydrotestosterone. Dihydrotestosterone causes the shrinkage of the hair follicles. It is also suggested the use of finasteride increases the number of hairs. Hair fall usually resumes within 6 to 12 months of the discontinuation of finasteride. It may cause libido and erectile dysfunction.
  • Corticosteroids
    Topical corticosteroids like betamethasone and hydrocortisone are used for the treatment of hair loss due to the autoimmune causes. They are immunosuppressive and prevents the immune system from attacking the hair follicles.
    Immunotherapy involves the application of diphencypronemay help in hair regrowth.
    Hair loss surgery such as hair transplantation, artificial hair implantation, scalp reduction, etc. can be done for cosmetic purposes though it is not the treatment of alopecia.
    Supportive measures like use of wigs and tattooing the affected area may help.

Prevention  of Alopecia

                            Not all the types of alopecia are preventable. Hair loss caused by drugs, stress, deficiency of protein and iron, hair styling, etc. can be prevented. Maintenance of good hair hygiene with regular shampooing can be beneficial. Reducing the stress can be beneficial. Stress reduction can be achieved by sleeping for at least 6 to 7 hours, maintaining a healthy diet, regular light physical exercise, thinking positive etc.  Treatment of the underlying causes of alopecia such as thyroid disorders, anaemia, and other hormonal imbalances help in preventing alopecia. Good dietary habits, including adequate levels of iron and vitamin ‘B’ in the diet, are very important in preventing alopecia. Hereditary and autoimmune alopecia cannot be prevented.


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