Types of Alopecia and Hair Loss

It is believed that alopecia is an autoimmune disease that affects hair and appears initially as a free-hair patch of one inch diameter. Alopecia affects both genders and often starts to emerge in childhood. According to a survey conducted in the United States, 1 in every 100 people is likely to be infected with alopecia at some point of their lives. Many people with alopecia will suffer from hair loss only once and then their hair grows back again. Yet it is estimated that about 20% of cases in the United Kingdom may experience alopecia repeatedly or suffer from it permanently.
There are three types of alopecia which are named according to their severity:
•    Alopecia Areata (AA)
Alopecia areata is a simple autoimmune condition which causes patchy hair loss.
•    Alopecia Totalis (AT)
Alopecia totalis results in total loss of all hair on the scalp.
•    Alopecia Universalis (AU)
Alopecia universalis results in total loss of all hair on scalp and body.

Researchers believe that alopecia is an autoimmune disease, meaning that the immune system considers hair follicles as if they were foreign objects and attacks them. Certain type of white blood cells called T-lymphocyte attacks hair follicles and prevents hair from growing resulting in the arrest of hair growth stage. After about three months, when this phase ends, old hair starts to fall. When T-lymphocyte stops attacking hair follicle, new hair starts to grow.

Seborrheic Alopecia
Seborrheic alopecia is a common skin disease and one of the most common hair loss problems for men which often appears among young and middle-aged men. It has been proven to be caused by greasy secretions from the scalp that causes glossy hair. This case occurs due to excessive greasy secretions from the sebaceous glands in hair follicles. People who suffer from excessive greasy secretions often experience increase in dandruff, an oily scalp and feeling a desire to scratch their scalp. 

Androgenic Alopecia – Male- Pattern Hair loss/ Female -Pattern Hair Loss
Androgenic alopecia represents 95% of total hair loss types. This disease can affect both men and women despite the fact that men suffer much more from hair loss. Androgenic alopecia in women occurs in the form of hair loss in most parts of the scalp. In men, however, hair loss starts as reduction of hair line and develops later to reduce the density of hair at the top of the head.

Causes of Androgenic Alopecia
In 400 BC, Hippocrates observed that eunuchs never suffered hair loss. Later, Aristotle also observed the same phenomenon. In 1940, Dr. James Hamilton concluded that the genetic factors of the male hormone (androgen) cause androgenic alopecia. 
Now it is known that the more specific cause of androgenic alopecia is the male sex hormone (DHT) which results from the conversion of testosterone by 5a-reductases, which contributes to the occurrence of male-pattern hair loss in those who have a genetic predisposition. It is interesting to note that people who suffer from a shortage of 5a-reductases do not experience male-pattern hair loss because their bodies are unable to convert testosterone into DHT. 
When male-pattern hair loss occurs, large hair follicles that are active in specific areas of the scalp become smaller and less active and shrink slightly with each new growth cycle. It is believed that 5a- reductase is the main reason for this as it works to convert testosterone to DHT causing shrinkage of hair shafts. As a result, hair gradually becomes thinner with each new growth cycle until it becomes transparent and stops growing completely. If a person is infected by male-pattern hair loss, their overall testosterone levels are normal but the activity of 5a-reductase is more than usual leading to increased DHT in hair follicles.

Increased Hair Loss /Hair Loss Associated with Cancer Treatment
Increased hair loss is a sudden fall of the hair which occurs as a result of chemicals or radiation, such as hair loss resulting from certain types of chemotherapy or radiation therapy.
In the case of increasing hair loss, hair does not enter the resting phase, as is the case with old hair loss (physiological hair loss). In this case, hair loss happens suddenly usually between 1-3 weeks after exposure to chemicals or radiation. Cancer treatments such as chemotherapy and radiation therapy are the most common causes of increasing hair loss. However, exposure to toxic chemicals such as arsenic and thallium also lead to a sudden loss of hair.
Chemotherapy in cancer treatment is used to destroy cancer cells that divide rapidly within the body. One side effect of cancer treatment is that hair stops growing and hair loss possibly occurs. In some cases, nearly 90% of hair may be affected and the remaining 10% will be in the resting phase. At that time, before treatment starts, some hair follicles may not drop hair, but produce thin and weak hair which can fall easily. 
Increasing hair loss caused by chemotherapy is only a temporary situation in most cases, and hair grows back normally once cancer treatment is over. Many people even claim that their new hair grows again healthier and thicker. Sometimes when hair grows again it can have a different texture. Some people who used to have curly hair noted that their hair has grown again straight and sometimes with different color. The most important thing to remember is that this situation of hair loss is not a permanent condition and once treatment is over, hair follicles recover and hair grows again.

Self-induced Hair Loss
Sometimes the damage that occurs to hair can be self-induced. There are two main types of self-induced hair loss: Trichotillomania (hair-pulling disorder) and alopecia caused by pulling hair.

Trichotillomania (Hair-Pulling Disorder)
Trichotillomania is a self-induced hair loss caused by continuous pulling of hair. It is more common among young adolescents, children, and women and affects women more than men with a ratio of 1: 2. The pulling of hair is often from different areas of the scalp; however, some people may pull out their eyebrows or eyelashes. In most cases, Trichotillomania treatment involves psychiatric counseling, but in some cases anti-depressant drugs may be prescribed.

Traction Alopecia 
Traction alopecia is the hair loss that occurs after persistent gentle pulling of hair caused by different hair styles. Hairstyles such as ponytails, buns and braids often lead to persistent pulling of hair which gradually causes hair loss. If hair pulling and falling stays for a long period, it could lead to permanent alopecia. In general, changing hairstyles that reduce hair pulling is all what you need to treat traction alopecia. 

Old Hair Loss
Hair loss associated with sudden stress leads to a low-level hair density. Old hair loss occurs in the case of sudden or severs stress. Sudden stress suppresses the growth of hair follicles and forces them into the resting phase. After about three months of this resting phase, a large amount of hair falls. Sometimes the person affected recovers from stress before hair loss occurs to him/her. In most cases, hair loss is temporary and hair is restored again in a short period. Yet in some cases, hair loss may continue until its causes are dealt with.

Drugs that Can Cause Hair Loss
It was reported that some drugs can cause hair loss to certain people while others who take these same drugs may not suffer hair loss. The following is a list of drugs which were reported to cause hair loss:
•    Allopurinol (used to treat gout)
•    Heparin (injectable blood thinner)
•    Coumarin (blood thinner)
•    Clofibrate (used to lower cholesterol levels in the blood)
•    Gemfibrozil (used to lower cholesterol levels in the blood)
These are but few examples of drugs which were reported to contribute in hair loss. If you suspect that the medication you take may cause hair loss you must counsel your doctor. 

Hair Loss Due to Severe Emotional Stress
Some people may suffer from old hair loss or sudden hair loss after experiencing a traumatic incident such as the death of a family member, exposure to accidents, abuse, and so on.  These kinds of sudden hair loss are usually temporary because hair grows again. Yet in some cases where the sudden hair loss occurs, hair loss may continue until its causes are addressed. These types include the following:
•    Dysfunction of the thyroid gland
•    Diabetes
•    Anemia
•    Systemic lupus erythematosus 
Hair loss caused by the above reasons usually continues until the underlying causes are dealt with. 

Dysfunction of the Thyroid Gland
In general, the physician should conduct a test on the thyroid’s function as the first test for a patient suffering from hair loss because problems of the thyroid gland can cause hair loss. There are two types of dysfunction of the thyroid gland and both can lead to hair loss: hypothyroidism (underactive thyroid gland) and goiter (high active thyroid gland).

Hypothyroidism - Lack of Thyroxine 
Hypothyroidism occurs when the thyroid gland produces too little thyroid hormone (thyroxine) to meet the body's needs.

Goiter – Increase of Thyroxine
Goiter happens when the thyroid gland produces too much thyroid hormone (thyroxine) to meet the body's needs. People with another case of autoimmune disease are, in particular, more likely to have goiter. 
Hair loss can occur as a result of both hypothyroidism and goiter. Some patients of either diseases experience little hair loss while others may suffer from severe hair loss. Fortunately, hair grows again when treated from thyroid problems. If you suspect that you are experiencing a problem in the thyroid function, you must visit a doctor.

Diabetes occurs when the body is unable to metabolize carbohydrates properly. Failure to treat diabetes causes hair loss.

Systemic Lupus Erythematosus 
This disease is one of the autoimmune diseases and causes inflammation in many organs of the body. The main signs are fever and rashes on the face, neck, hands and arms. About half of the patients with SLE suffer hair loss. SLE is most common among women aged 20 to 50 years. It is believed that genetic factors play a major role in the emergence of this disease.

Cicatricial Alopecia
The inflammation of hair follicles as a result of infection can lead to cicatricial alopecia (also known as scarring alopecia). A severe condition of cicatricial alopecia is easily recognizable because there will be rough spots on the surface of the scalp made up of small blood vessels and connective tissue. Reasons and different types of cicatricial alopecia are discussed below.

Cicatricial Alopecia caused by Discoid Lupus Erythematosus
Discoid lupus erythematosus (DLE) is a disease that affects connective tissue and can lead to loss of scalp hair. This disease appears in the form of circular pustules the diameter of each ranges between 5-10 mm accompanied with blockage of hair follicles and peeling of the scalp or lack of it. In the final stage, the skin becomes smooth and lank with a lot of scars. DLE is sensitive to sunlight and therefore exposure to sunlight must be minimized. Topical steroids such as triamcinolone acetonide are useful in the treatment of small pimples and anti-malaria medicines such as hydroxy quinolone are considered useful in the treatment of DLE.
Cutaneous Lichen Planus
Cutaneous lichen planus (CLP) is a skin disease commonly affects about 1% of the population. It is an inflammatory disease of the skin and mucous membranes and usually begins in the form of itchy patches in the front of the wrists, forearms, sides of the legs, ankles, and lower back. In rare cases, CLP can affect the scalp and other hairy areas and appears on the scalp like red or purple pimples with blockage of hair follicles, which usually goes away. Steroids are used to relieve the desire to scratch, and anti-malaria medicines may reduce the inflammation.

Pseudopelade is a rare type of cicatricial alopecia which prevents hair from growing again and usually affects middle-aged people.

Congenital Disorder of Skin 
Congenital disorder of skin is a rare disorder when a small ulcer usually appears at birth in the midline of the scalp. Most cases are cured naturally, but in the case of large ulcers, it can be accompanied by disturbances in the growth and development of the child.

Congenital Baldness
Congenital baldness occurs when a child is born without hair follicles in certain areas. This case can be quite common, and usually occurs only in certain spots that can be easily covered.

Other Types of Hair Loss
This section discusses few other different types of hair loss that has not been discussed in the previous sections.

Syphilis Baldness
Syphilis baldness is a virtual symptom of mesosyphilis. Baldness appears in the form of patches, and often described as moth-eaten. This disease is diagnosed through a blood test or microscopic examination and penicillin is often used in treatment.

Scleroderma is a disease that causes skin hardening and tightening and it occurs as a result of excessive production of collagen. When it appears on the scalp, it interferes with the normal functioning of hair follicles and hair growth. Scleroderma symptoms can range from mild, where just few spots appear on the skin, to severe that affects the internal organs. Sever sclerosis is known as systemic sclerosis which is more common among women and usually begins between the ages of 40-60 years.

Tinea Capitis
Tinea capitis (another name for ringworm) appears on the scalp, is highly contagious and can spread in a whole school, nursery school or family. It can transmit from animals to humans as well. Major symptoms or signs include peeling and redness of a round bald area or separate areas where fungi digest the keratin found in hair. Bald patches spread slowly with the spread of the disease. Antifungals are considered the most common treatment for ringworm and patients take the medicine once a day for four to twelve weeks. In addition to oral therapy, sometimes Nizoral shampoo is prescribed (contains 2% of ketoconazole) to reduce the size of the infected area.