Loss of hair / hair, also called alopecia, can occur anywhere on the body. The hair loss that happens on the scalp is usually called baldness. Hair loss usually generates great concern in people for aesthetic reasons, but it can also be a sign of a disorder that attacks the (systemic) organism.
Hair and hair grow in cycles. Each cycle consists of:
- A long growth phase
- A brief transitional phase
- A short rest period
At the end of the resting phase, the hairs fall and new begin to grow in the follicle, indicating that the cycle will be repeated. Generally, about 50 to 100 strands of hair arrive, every day, at the end of the resting phase, and fall off. When an amount greater than 100 hairs / day enters the resting phase, hair loss may occur. Effluvium is the interruption of the growth phase that causes hair loss.
The most common causes of hair loss are;
- Alopecia aerate
- Certain systemic disorders, such as those that cause high fever, systemic lupus erythematous (lupus), hormonal disorders and nutritional deficiencies
- Medications, especially chemotherapy
- Fungal infections, such as the scalp’s tinea capitis (tinea capitis)
- Physical stress, such as high fever, surgery, a serious illness, sudden weight loss or pregnancy (which can lead to telogen effluvium).
- Injury (trauma)
Hair follicle injury has many causes, including:
- Trichotillomania (a habit of pulling normal hair related to psychological stress)
- Traction alopecia, which is the loss of hair caused by continuous traction such as braids, cokes or ponytails.
- Central centrifugal cicatricle alopecia (hair loss with scarring of the scalp, associated with the use of hot combs, chemical relaxers and hair extensions)
- Burns and radiation
- Pressure-induced hair loss
This type of alopecia can end up affecting up to 80% of white men around the age of 70 (male pattern of hair loss) and about half of all women (female pattern of hair loss). The hormone dihydrotestosterone plays an important role, along with heredity. Hair loss can start at any age, during or after puberty, even during adolescence (hair loss).
In alopecia areata, there is a sudden loss of round and irregular hair locks. It is believed that this disorder is caused by a dysfunction of the body’s immune system that causes it to attack its own tissues (called an autoimmune reaction).
Centrifugal central cicatricle alopecia
Central centrifugal cicatricial alopecia is the most common cause of scarring alopecia in black people, occurring usually in women of African descent. Scalp damage, such as those coming from hot combs, chemical relaxants or hair extensions, in association with predisposition to follicular damage due to abnormal hair follicles results in progressive hair loss and scarring on the upper and posterior scalp.
Cutaneous lupus erythematosus
In cutaneous lupus erythematosus, there may be loss of hair areas. Hair loss can be permanent if the hair follicle is completely destroyed. Cutaneous lupus erythematosus can affect people who have or do not have systemic lupus erythematosus (SLE), a condition in which antibodies or cells produced by the body attack the body’s own tissues (called an autoimmune disease). Systemic lupus erythematosus affects several organs throughout the body. In cutaneous lupus erythematosus, hair tends to fall in strands.
If women have excessive amounts of male hormones, they can develop male characteristics (called virilization), such as thicker voice, acne, hair in places where their growth is more common in men, such as the face and trunk (hirsutism). Virilization may also include hair loss. The most common cause of virilization is polycystic ovary syndrome (PCOS). Rarely, the tumor can secrete male hormones, provoking virilization, or virilization can develop in a woman who is making use of anabolic steroids to improve athletic performance.
Nutritional disorders are a less common cause of hair loss. Symptoms vary according to the specific nutritional disorder:
- Excess vitamin A
- Iron deficiency
- Zinc deficiency
The male and female pattern of hair loss can sometimes be effectively treated through medication.
Minoxidil can prevent further hair loss and increase hair growth when applied directly to the scalp twice a day. It can take 8 to 12 months for hair to grow again, and that fact is noticeable in only 30 to 40% of people. The most common side effect is skin irritation, such as itching and rashes. There may also be an increase in facial hair.
Finasteride works by blocking the effects of the male hormones on the hair follicles and can be administered daily by mouth. Finasteride is not used in women. In men, its effectiveness in stopping hair loss and stimulating its growth is usually evident within 6 to 8 months of treatment and increases over time, but may vary from person to person.
Hormonal modulators, such as birth control pills (oral contraceptives) or spironolactone, may be helpful in some women, especially those who have developed male characteristics.
Transplantation is a more permanent solution. In this procedure, the hair follicles are removed from a part of the scalp and transplanted into areas that have baldness. In this technique, only one or two hair strands are transplanted at a time. Although this technique takes a long time, it does not require the extraction of large fractions of the skin and allows giving the implants an orientation, according to the direction of the natural hair.