Hair follicles are small structures at the base of the hair roots where new hairs grow from. They produce new skin cells called sebum which helps keep your scalp healthy and moisturized. Hair follicles are located all over the body including the head, neck, armpits and groin.
The main function of hair follicles is to produce new skin cells called keratinocytes (skin cells). Keratinocytes are responsible for keeping the surface of your skin smooth and soft. When they die, these dead cells cause dryness or flaking of the skin. The sebum or natural oil secreted by the skin glands nourishes the skin. Excess of this oil clogs the pores and causes acne, blackheads or whiteheads.
Any injury or infection on the skin can alter the function of hair and skin. This causes an overproduction of these cells. This excess in turn produces hillocks, which are hard and painful bumps in the skin. These cells also multiply and form into cysts or fluid-filled sacs.
Hair follicle tumors can be benign or malignant. Benign tumors are not life threatening and do not spread to nearby tissue or other parts of the body. On the other hand, malignant tumors can spread to other parts of the body through the blood and lymphatic systems.
Trichofolliculoma is a benign tumor that causes an overgrowth of hair. It may look like a small pink bump on the skin that may look like a worm or a string under the skin. It is most often found on the upper back, neck, head and shoulder blades. It can also be triggered by trauma to the skin.
Pilomatricoma is a tumor that forms under the skin from the cells that produce hair. It can be found on the skin surface and sometimes inside the hair follicles. It is most often found on the scalp, face, neck, arms and legs.
Calcifying Folliculitis is a type of skin lesion or growth that typically appears as a small, hard lump under the skin. It is usually painless and does not itch. It can be confused with skin cancer. In some cases, the lumps can be felt just under the skin.
Pilomatrixomas are common benign tumors that affect the skin’s hair structures. They can affect both children and adults. They are non-cancerous (benign) tumors that form in the skin’s hair structures. They grow very slowly and may cause no symptoms.
Folliculotropic: Folliculotropic is the medical term for hair growth stimulant. A hair growth stimulator is any product that claims to enhance or boost your natural hair growth cycle.
Trichotillomania is a psychological condition that causes an irresistible urge to pull out one’s own hair. The user gets a feeling of pleasure when they pull out their own hair. It is mostly a problem in children but can persist into adulthood. It is often accompanied by anxiety, depression and obsessive-compulsive disorder. When the hair pulling is severe, it can lead to noticeable hair loss.
Trichophagia is an extreme condition in which the user eats his or her own hair. It is usually caused by a nutrient deficiency or gastrointestinal problems. It can be treated with dietary changes.
Alopecia areata is a condition in which the immune system attacks and destroys the hair follicles, resulting in smooth, round patches of hair loss. It occurs when the body’s immune system attacks and destroys the hair follicles. The exact cause is unknown, however stress and hormonal changes can play a role.
Hair strands naturally fall out all the time. Hair loss only becomes a problem when it occurs in excessive amounts. The most common culprits are stress, hormonal changes, nutritional deficiencies and certain medications. Changes in diet, stress and an excessive consumption of alcohol can also cause hair loss.
Telogen effluvium is another condition in which the hair falls out. In this condition, large numbers of hairs enter the resting phase at the same time and then fall out. This can happen after an illness, surgery, childbirth or other forms of physical trauma. It is also the most common type of hair loss in women who are experiencing severe emotional trauma such as through child abuse.
The main types of hair loss are:
Androgenic Alopecia is the most common type of hair loss and is caused by a genetic sensitivity to the hormone DHT. It affects half of all men and a quarter of all women. The hair loss starts at the temples in a horseshoe pattern and progresses to all areas of the scalp over time.
Alopecia areata is an autoimmune disorder that causes the body to attack its own anagen hair follicles, causing sudden onset of patchy hair loss.
Alopecia Totalis is the loss of all hair on the scalp, including eyebrow and eyelash hair. It is a rare condition that typically occurs in men. Commonly, the only hair loss is of the eyebrow hair.
Alopecia Universalis is the loss of all hair on the scalp and body, including eyebrow and eyelash hair. It is a very rare condition that typically occurs in men.
Ludwig’s Angina is an infection of the gums that spread to the jawbone and causes severe pain. It is caused by poor dental hygiene and insufficient treatment of teeth problems.
The most common cause of hair loss in women is Female Pattern Baldness, which affects 2 out of 3 women. It is caused by a sensitivity to DHT, which kills the Anagen hair follicles. This condition causes a widening of the part in the hair, followed by a gradual thinning throughout the top and crown of the head, with eventual disappearance of hair above the temples.
Before the development of wigs and other hair pieces, hats were essential to mask the loss of hair. The most desirable were those made from the hair of children, as their hair was often the most luxurious. It was not until the introduction of human hair wigs that hat styles changed.
In the past, wigs were often powdered to try and give them a more realistic appearance. This was largely because the use of human hair for wigs was very rare, due to its high price. One way to tell if a wig is made from human hair, that it has a natural top knot.
The most common type of hair loss is Male Pattern Baldness. It affects half of all men by the age of 50 and nearly all men by the age of 70. In this condition, a hormone called DHT actively attacks the Anagen hair follicles. The onset of hair loss is gradual and the hair loss itself is patchy.
The second most common type of hair loss is Female Pattern Baldness. It affects 2 out of 3 women by the age of 50. This type of hair loss is caused by a sensitivity to the hormone DHT, which attacks the Anagen hair follicles. It commonly begins at the temples and causes a widening of the part. Over time, this leads to a thinning of the hair throughout the top and crown of the head until the hair is no longer present.
Alopecia areata is an autoimmune disorder that causes the body to attack its own Anagen hair follicles, causing sudden onset of patchy hair loss. The hair loss is typically painless and unrelated to other triggers such as stress. It commonly occurs in men and women of all ages.
Telogen effluvium is a condition that causes large amounts of hair to enter the Telogen phase. This leads to a sudden increase in shedding, as large amounts of hair enter the Telogen and Exogen phase. This condition typically occurs following a stressful event, surgery or a major illness.
Trichotillomania is the compulsive urge to pull out one’s own hair. This condition typically causes patchy hair loss that is often unnoticed by others.
Alopecia Areata is a type of hair loss that is caused by an autoimmune condition, which attacks the hair follicles and causes them to shut down. This condition typically causes painless and rapid hair loss that most commonly occurs on the scalp, but may occur on other parts of the body. Loss of eyebrows is a common occurrence with this condition.
Infection of the hair roots, which are buried under the skin, is a rare cause of hair loss. It typically causes pain, swelling and redness at the location of infection.
A localized infection at the base of a hair root, which prevents the hair from growing. This may be caused by a buildup of sebum, chemical burn or an ingrown hair.
Sources & references used in this article:
- β‐Catenin gene mutation in human hair follicle‐related tumors (Y Kajino, A Yamaguchi, N Hashimoto… – Pathology …, 2001 – Wiley Online Library)
- Hair follicle tumors resembling tricholemmomas in six dogs (RW Diters, MH Goldschmidt – Veterinary pathology, 1983 – journals.sagepub.com)
- Hair cycle regulation of Hedgehog signal reception (AE Oro, K Higgins – Developmental biology, 2003 – Elsevier)
- Tumors of the hair follicle. A review. (JT Headington – The American journal of pathology, 1976 – ncbi.nlm.nih.gov)