Hair loss, also known as alopecia or baldness, refers to a loss of
hair
Hair is a protein filament that grows from follicles found in the dermis. Hair is one of the defining characteristics of mammals.
The human body, apart from areas of glabrous skin, is covered in follicles which produce thick terminal and f ...
from part of the head or body.
Typically at least the head is involved.
[ The severity of hair loss can vary from a small area to the entire body.] Inflammation
Inflammation (from la, wikt:en:inflammatio#Latin, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or Irritation, irritants, and is a protective response involving im ...
or scarring
A scar (or scar tissue) is an area of fibrous tissue that replaces normal skin after an injury. Scars result from the biological process of wound repair in the skin, as well as in other organs, and tissues of the body. Thus, scarring is a na ...
is not usually present.[ Hair loss in some people causes ]psychological distress
Mental distress or psychological distress encompasses the symptoms and experiences of a person's internal life that are commonly held to be troubling, confusing or out of the ordinary. Mental distress can potentially lead to a change of behavior, a ...
.
Common types include male- or female-pattern hair loss, alopecia areata
Alopecia areata, also known as spot baldness, is a condition in which hair is lost from some or all areas of the body. Often, it results in a few bald spots on the scalp, each about the size of a coin. Psychological stress and illness are po ...
, and a thinning of hair known as telogen effluvium
Telogen effluvium is a scalp disorder characterized by the thinning or shedding of hair resulting from the early entry of hair in the telogen phase (the resting phase of the hair follicle).Marks, James G; Miller, Jeffery (2006). ''Lookingbill and ...
.[ The cause of male-pattern hair loss is a combination of ]genetics
Genetics is the study of genes, genetic variation, and heredity in organisms.Hartl D, Jones E (2005) It is an important branch in biology because heredity is vital to organisms' evolution. Gregor Mendel, a Moravian Augustinian friar wor ...
and male hormones
Sex hormones, also known as sex steroids, gonadocorticoids and gonadal steroids, are steroid hormones that interact with vertebrate steroid hormone receptors. The sex hormones include the androgens, estrogens, and progestogens. Their effects are ...
; the cause of female pattern hair loss is unclear; the cause of alopecia areata is autoimmune
In immunology, autoimmunity is the system of immune responses of an organism against its own healthy cells, tissues and other normal body constituents. Any disease resulting from this type of immune response is termed an "autoimmune disease". P ...
; and the cause of telogen effluvium is typically a physically or psychologically stressful event.[ Telogen effluvium is very common following ]pregnancy
Pregnancy is the time during which one or more offspring develops ( gestates) inside a woman's uterus (womb). A multiple pregnancy involves more than one offspring, such as with twins.
Pregnancy usually occurs by sexual intercourse, but ca ...
.
Less common causes of hair loss without inflammation or scarring include the pulling out of hair, certain medications including chemotherapy
Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemotherap ...
, HIV/AIDS
Human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV), a retrovirus. Following initial infection an individual ...
, hypothyroidism
Hypothyroidism (also called ''underactive thyroid'', ''low thyroid'' or ''hypothyreosis'') is a disorder of the endocrine system in which the thyroid gland does not produce enough thyroid hormone. It can cause a number of symptoms, such as po ...
, and malnutrition
Malnutrition occurs when an organism gets too few or too many nutrients, resulting in health problems. Specifically, it is "a deficiency, excess, or imbalance of energy, protein and other nutrients" which adversely affects the body's tissues a ...
including iron deficiency
Iron deficiency, or sideropenia, is the state in which a body lacks enough iron to supply its needs. Iron is present in all cells in the human body and has several vital functions, such as carrying oxygen to the tissues from the lungs as a key ...
.[ Causes of hair loss that occurs with scarring or inflammation include ]fungal infection
Fungal infection, also known as mycosis, is disease caused by fungi. Different types are traditionally divided according to the part of the body affected; superficial, subcutaneous, and systemic. Superficial fungal infections include common ti ...
, lupus erythematosus
Lupus erythematosus is a collection of autoimmune diseases in which the human immune system becomes hyperactive and attacks healthy tissues. Symptoms of these diseases can affect many different body systems, including joints, skin, kidneys, blo ...
, radiation therapy
Radiation therapy or radiotherapy, often abbreviated RT, RTx, or XRT, is a therapy using ionizing radiation, generally provided as part of cancer treatment to control or kill malignant cells and normally delivered by a linear accelerator. Radia ...
, and sarcoidosis
Sarcoidosis (also known as ''Besnier-Boeck-Schaumann disease'') is a disease involving abnormal collections of inflammatory cells that form lumps known as granulomata. The disease usually begins in the lungs, skin, or lymph nodes. Less commonly af ...
.[ Diagnosis of hair loss is partly based on the areas affected.][
Treatment of pattern hair loss may simply involve accepting the condition, which can also include shaving one's head.][ Interventions that can be tried include the medications ]minoxidil
Minoxidil, sold under the brand name Rogaine among others, is a medication used for the treatment of high blood pressure and pattern hair loss. It is an antihypertensive vasodilator. It is available as a generic medication by prescription in ora ...
(or finasteride
Finasteride, sold under the brand names Proscar and Propecia among others, is a medication used to treat hair loss and benign prostatic hyperplasia (BPH) in men. It can also be used to treat excessive hair growth in women and as a part of horm ...
) and hair transplant surgery
Hair transplantation is a surgical technique that removes hair follicles from one part of the body, called the 'donor site', to a bald or balding part of the body known as the 'recipient site'. The technique is primarily used to treat male patt ...
. Alopecia areata may be treated by steroid
A steroid is a biologically active organic compound with four rings arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that alter membrane fluidity; and a ...
injections in the affected area, but these need to be frequently repeated to be effective.[ Hair loss is a common problem.][ Pattern hair loss by age 50 affects about half of men and a quarter of women.][ About 2% of people develop alopecia areata at some point in time.][
]
Terminology
Baldness is the partial or complete lack of hair growth, and part of the wider topic of "hair thinning". The degree and pattern of baldness varies, but its most common cause is androgenic hair loss
Pattern hair loss (also known as androgenetic alopecia (AGA)) is a hair loss condition that primarily affects the top and front of the scalp. In male-pattern hair loss (MPHL), the hair loss typically presents itself as either a receding front ha ...
, ''alopecia androgenetica'', or ''alopecia seborrheica'', with the last term primarily used in Europe.
Hypotrichosis
Hypotrichosis is a condition of abnormal hair patterns, predominantly loss or reduction. It occurs, most frequently, by the growth of vellus hair
Vellus hair is short, thin, light-colored, and barely noticeable hair that develops on most of a human’s body during childhood. Exceptions include the lips, the back of the ear, the palm of the hand, the sole of the foot, some external genital ...
in areas of the body that normally produce terminal hair
In humans, terminal hair is a variant of hair that is thick and long such as what grows on the scalp, as compared with vellus hair, colloquially known as peach fuzz, growing elsewhere.Marks, James G; Miller, Jeffery (2006)''Lookingbill and Ma ...
. Typically, the individual's hair growth
The growth of human hair occurs everywhere on the body except for the soles of the feet, the inside of the mouth, the lips, the backs of the ears, the palms of the hands, some external genital areas, the navel, scar tissue, and, apart from eyela ...
is normal after birth, but shortly thereafter the hair is shed and replaced with sparse, abnormal hair growth. The new hair is typically fine, short and brittle, and may lack pigmentation. Baldness may be present by the time the subject is 25 years old.
Signs and symptoms
Symptoms of hair loss include hair loss in patches usually in circular patterns, dandruff, skin lesions, and scarring. Alopecia areata (mild – medium level) usually shows in unusual hair loss areas, e.g., eyebrows, backside of the head or above the ears, areas the male pattern baldness usually does not affect. In male-pattern hair loss, loss and thinning begin at the temples and the crown and hair either thins out or falls out. Female-pattern hair loss occurs at the frontal
Front may refer to:
Arts, entertainment, and media Films
* ''The Front'' (1943 film), a 1943 Soviet drama film
* ''The Front'', 1976 film
Music
* The Front (band), an American rock band signed to Columbia Records and active in the 1980s and e ...
and parietal.
People have between 100,000 and 150,000 hairs on their head. The number of strands normally lost in a day varies but on average is 100. In order to maintain a normal volume, hair must be replaced at the same rate at which it is lost. The first signs of hair thinning that people will often notice are more hairs than usual left in the hairbrush after brushing or in the basin after shampooing. Styling can also reveal areas of thinning, such as a wider parting or a thinning crown.
Skin conditions
A substantially blemished face, back and limbs could point to cystic acne. The most severe form of the condition, cystic acne
Acne, also known as ''acne vulgaris'', is a long-term skin condition that occurs when dead skin cells and oil from the skin clog hair follicles. Typical features of the condition include blackheads or whiteheads, pimples, oily skin, and po ...
, arises from the same hormonal imbalances that cause hair loss and is associated with dihydrotestosterone
Dihydrotestosterone (DHT, 5α-dihydrotestosterone, 5α-DHT, androstanolone or stanolone) is an endogenous androgen sex steroid and hormone. The enzyme 5α-reductase catalyzes the formation of DHT from testosterone in certain tissues includi ...
production.
Psychological
The psychology
Psychology is the scientific study of mind and behavior. Psychology includes the study of conscious and unconscious phenomena, including feelings and thoughts. It is an academic discipline of immense scope, crossing the boundaries betwe ...
of hair thinning is a complex issue. Hair is considered an essential part of overall identity: especially for women, for whom it often represents femininity and attractiveness. Men typically associate a full head of hair with youth and vigor. People experiencing hair thinning often find themselves in a situation where their physical appearance is at odds with their own self-image
Self-image is the mental picture, generally of a kind that is quite resistant to change, that depicts not only details that are potentially available to an objective investigation by others (height, weight, hair color, etc.), but also items that h ...
and commonly worry that they appear older than they are or less attractive to others. Psychological problems due to baldness, if present, are typically most severe at the onset of symptoms.
Hair loss induced by cancer chemotherapy
Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemotherap ...
has been reported to cause changes in self-concept
In the psychology of self, one's self-concept (also called self-construction, self-identity, self-perspective or self-structure) is a collection of beliefs about oneself. Generally, self-concept embodies the answer to the question ''"Who am I? ...
and body image
Body image is a person's thoughts, feelings and perception of the aesthetics or sexual attractiveness of their own body. The concept of body image is used in a number of disciplines, including neuroscience, psychology, medicine, psychiatry, ps ...
. Body image does not return to the previous state after regrowth of hair for a majority of patients. In such cases, patients have difficulties expressing their feelings (alexithymia
Alexithymia is a personality trait characterized by the inability to identify and describe emotions experienced by oneself. The core characteristic of alexithymia is marked dysfunction in emotional awareness, social attachment, and interpersonal ...
) and may be more prone to avoiding family conflicts. Family therapy can help families to cope with these psychological problems if they arise.
Causes
Although not completely understood, hair loss can have many causes:
Pattern hair loss
Male pattern hair loss is believed to be due to a combination of genetics and the male hormone dihydrotestosterone
Dihydrotestosterone (DHT, 5α-dihydrotestosterone, 5α-DHT, androstanolone or stanolone) is an endogenous androgen sex steroid and hormone. The enzyme 5α-reductase catalyzes the formation of DHT from testosterone in certain tissues includi ...
. The cause in female pattern hair loss remains unclear.
Infection
* Dissecting cellulitis of the scalp
Dissecting cellulitis of the scalp, also known as dissecting folliculitis, perifolliculitis capitis abscedens et suffodiens of Hoffman, perifolliculitis abscedens et suffodiens, or folliculitis abscedens et suffodiens, is an inflammatory condition ...
* Fungal infection
Fungal infection, also known as mycosis, is disease caused by fungi. Different types are traditionally divided according to the part of the body affected; superficial, subcutaneous, and systemic. Superficial fungal infections include common ti ...
s (such as tinea capitis
Tinea capitis (also known as "herpes tonsurans", "ringworm of the hair", "ringworm of the scalp", "scalp ringworm", and "tinea tonsurans") is a cutaneous fungal infection (dermatophytosis) of the scalp. The disease is primarily caused by dermatoph ...
)
* Folliculitis
Folliculitis is the infection and inflammation of one or more hair follicles. The condition may occur anywhere on hair-covered skin. The rash may appear as pimples that come to white tips on the face, chest, back, arms, legs, buttocks, or head.
A ...
from various causes
** Demodex folliculitis, caused by ''Demodex folliculorum
''Demodex folliculorum'' is a microscopic mite that can only survive on the skin of humans. Most people have ''D.folliculorum'' on their skin. Usually, the mites do not cause any harm, so are considered an example of commensalism rather than par ...
'', a microscopic mite that feeds on the sebum produced by the sebaceous gland
A sebaceous gland is a microscopic exocrine gland in the skin that opens into a hair follicle to secrete an oily or waxy matter, called sebum, which lubricates the hair and skin of mammals. In humans, sebaceous glands occur in the greatest number ...
s, denies hair essential nutrients and can cause thinning. ''Demodex folliculorum'' is not present on every scalp and is more likely to live in an excessively oily scalp environment.
* Secondary syphilis
Syphilis () is a sexually transmitted infection caused by the bacterium ''Treponema pallidum'' subspecies ''pallidum''. The signs and symptoms of syphilis vary depending in which of the four stages it presents (primary, secondary, latent, an ...
Drugs
* Temporary or permanent hair loss can be caused by several medications, including those for blood pressure
Blood pressure (BP) is the pressure of circulating blood against the walls of blood vessels. Most of this pressure results from the heart pumping blood through the circulatory system. When used without qualification, the term "blood pressure" r ...
problems, diabetes
Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level ( hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased ap ...
, heart disease
Cardiovascular disease (CVD) is a class of diseases that involve the heart or blood vessels. CVD includes coronary artery diseases (CAD) such as angina and myocardial infarction (commonly known as a heart attack). Other CVDs include stroke, hea ...
and cholesterol
Cholesterol is any of a class of certain organic molecules called lipids. It is a sterol (or modified steroid), a type of lipid. Cholesterol is biosynthesized by all animal cells and is an essential structural component of animal cell mem ...
. Any that affect the body's hormone balance can have a pronounced effect: these include the contraceptive pill, hormone replacement therapy
Hormone replacement therapy (HRT), also known as menopausal hormone therapy or postmenopausal hormone therapy, is a form of hormone therapy used to treat symptoms associated with female menopause. These symptoms can include hot flashes, vaginal ...
, steroid
A steroid is a biologically active organic compound with four rings arranged in a specific molecular configuration. Steroids have two principal biological functions: as important components of cell membranes that alter membrane fluidity; and a ...
s and acne
Acne, also known as ''acne vulgaris'', is a long-term Cutaneous condition, skin condition that occurs when Keratinocyte, dead skin cells and Sebum, oil from the skin clog hair follicles. Typical features of the condition include comedo, black ...
medications.
* Some treatments used to cure mycotic
Fungal infection, also known as mycosis, is disease caused by fungi. Different types are traditionally divided according to the part of the body affected; superficial, subcutaneous, and systemic. Superficial fungal infections include common ti ...
infections can cause massive hair loss.
* Medications (side effects from drugs, including chemotherapy
Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemotherap ...
, anabolic steroids
Anabolic steroids, also known more properly as anabolic–androgenic steroids (AAS), are steroidal androgens that include natural androgens like testosterone as well as synthetic androgens that are structurally related and have similar effects t ...
, and birth control pill
The combined oral contraceptive pill (COCP), often referred to as the birth control pill or colloquially as "the pill", is a type of birth control that is designed to be taken orally by women. The pill contains two important hormones: progest ...
s)
Trauma
* Traction alopecia
Traction alopecia is a type of alopecia or hair loss caused by a chronic pulling force being applied to the hair. It commonly results from a person frequently wearing their hair in a particularly tight ponytail, pigtails, or braids with increased o ...
is most commonly found in people with ponytail
A ponytail is a hairstyle in which some, most or all of the hair on the head is pulled away from the face, gathered and secured at the back of the head with a hair tie, clip, or other similar accessory and allowed to hang freely from that point ...
s or cornrows
Cornrows are a traditional style of braids in which the hair is braided very close to the scalp, using an underhand, upward motion to make a continuous, raised row. Cornrows are often done in simple, straight lines, as the term implies, but they ...
who pull on their hair with excessive force. In addition, rigorous brushing and heat styling, rough scalp massage can damage the cuticle
A cuticle (), or cuticula, is any of a variety of tough but flexible, non-mineral outer coverings of an organism, or parts of an organism, that provide protection. Various types of "cuticle" are non- homologous, differing in their origin, structu ...
, the hard outer casing of the hair. This causes individual strands to become weak and break off, reducing overall hair volume.
* Frictional alopecia
Frictional alopecia is the loss of hair that is caused by rubbing of the hair, follicles, or skin around the follicle. The most typical example of this is the loss of ankle hair among people who wear socks constantly for years. The hair may not gro ...
is hair loss caused by rubbing of the hair or follicles, most infamously around the ankles of men from socks, where even if socks are no longer worn, the hair often will not grow back.
* Trichotillomania
Trichotillomania (TTM), also known as hair-pulling disorder or compulsive hair pulling, is a mental disorder characterized by a long-term urge that results in the pulling out of one's own hair. A brief positive feeling may occur as hair is remov ...
is the loss of hair caused by compulsive pulling and bending of the hairs. Onset of this disorder tends to begin around the onset of puberty and usually continues through adulthood. Due to the constant extraction of the hair roots, permanent hair loss can occur.
* Traumas such as childbirth, major surgery, poisoning, and severe stress may cause a hair loss condition known as telogen effluvium
Telogen effluvium is a scalp disorder characterized by the thinning or shedding of hair resulting from the early entry of hair in the telogen phase (the resting phase of the hair follicle).Marks, James G; Miller, Jeffery (2006). ''Lookingbill and ...
, in which a large number of hairs enter the resting phase at the same time, causing shedding and subsequent thinning. The condition also presents as a side effect of chemotherapy
Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemotherap ...
– while targeting dividing cancer cells, this treatment also affects hair's growth phase with the result that almost 90% of hairs fall out soon after chemotherapy starts.
* Radiation to the scalp, as when radiotherapy is applied to the head for the treatment of certain cancers there, can cause baldness of the irradiated areas.
Pregnancy
Hair loss often follows childbirth
Childbirth, also known as labour and delivery, is the ending of pregnancy where one or more babies exits the internal environment of the mother via vaginal delivery or caesarean section. In 2019, there were about 140.11 million births globall ...
in the postpartum period
The postpartum (or postnatal) period begins after childbirth and is typically considered to end within 6 weeks as the mother's body, including hormone levels and uterus size, returns to a non-pregnant state. The terms puerperium, puerperal perio ...
without causing baldness. In this situation, the hair is actually thicker during pregnancy owing to increased circulating oestrogens. Approximately three months after giving birth (typically between 2 and 5 months), oestrogen levels drop and hair loss occurs, often particularly noticeably around the hairline and temple
A temple (from the Latin ) is a building reserved for spiritual rituals and activities such as prayer and sacrifice. Religions which erect temples include Christianity (whose temples are typically called churches), Hinduism (whose temples ...
area. Hair typically grows back normally and treatment is not indicated. A similar situation occurs in women taking the fertility-stimulating drug clomiphene
Clomifene, also known as clomiphene, is a medication used to treat infertility in women who do not ovulate, including those with polycystic ovary syndrome. Use results in a greater chance of twins. It is taken by mouth once a day, with a course ...
.
Other causes
* Autoimmune disease. Alopecia areata
Alopecia areata, also known as spot baldness, is a condition in which hair is lost from some or all areas of the body. Often, it results in a few bald spots on the scalp, each about the size of a coin. Psychological stress and illness are po ...
is an autoimmune disorder
An autoimmune disease is a condition arising from an abnormal immune response to a functioning body part. At least 80 types of autoimmune diseases have been identified, with some evidence suggesting that there may be more than 100 types. Nearly a ...
also known as "spot baldness" that can result in hair loss ranging from just one location (''Alopecia areata monolocularis'') to every hair on the entire body (''Alopecia areata universalis''). Although thought to be caused by hair follicles becoming dormant, what triggers alopecia areata is not known. In most cases the condition corrects itself, but it can also spread to the entire scalp (alopecia totalis
Alopecia totalis is the loss of all hair on the head and face. Its causes are unclear, but believed to be autoimmune. Research suggests there may be a genetic component linked to developing alopecia totalis; the presence of DRB1*0401 and DQB1*0301 ...
) or to the entire body (alopecia universalis
__NOTOC__
Alopecia universalis (AU), also known as alopecia areata universalis, is a medical condition involving the loss of all body hair, including eyebrows, eyelashes, chest hair, armpit hair, and pubic hair. It is the most severe form of alop ...
).
* Skin diseases and cancer. Localized or diffuse hair loss may also occur in cicatricial alopecia (lupus erythematosus
Lupus erythematosus is a collection of autoimmune diseases in which the human immune system becomes hyperactive and attacks healthy tissues. Symptoms of these diseases can affect many different body systems, including joints, skin, kidneys, blo ...
, lichen plano pilaris, folliculitis decalvans, central centrifugal cicatricial alopecia, postmenopausal frontal fibrosing alopecia, etc.). Tumours and skin outgrowths also induce localized baldness (sebaceous nevus, basal cell carcinoma, squamous cell carcinoma).
* Hypothyroidism
Hypothyroidism (also called ''underactive thyroid'', ''low thyroid'' or ''hypothyreosis'') is a disorder of the endocrine system in which the thyroid gland does not produce enough thyroid hormone. It can cause a number of symptoms, such as po ...
(an under-active thyroid
The thyroid, or thyroid gland, is an endocrine gland in vertebrates. In humans it is in the neck and consists of two connected lobes. The lower two thirds of the lobes are connected by a thin band of tissue called the thyroid isthmus. The thy ...
) and the side effects of its related medications can cause hair loss, typically frontal, which is particularly associated with thinning of the outer third of the eyebrows (also seen with syphilis). Hyperthyroidism
Hyperthyroidism is the condition that occurs due to excessive production of thyroid hormones by the thyroid gland. Thyrotoxicosis is the condition that occurs due to excessive thyroid hormone of any cause and therefore includes hyperthyroidism ...
(an over-active thyroid) can also cause hair loss, which is parietal rather than frontal.
* Sebaceous cysts. Temporary loss of hair can occur in areas where sebaceous cyst
A sebaceous cyst is a term commonly used to refer to either:
* Epidermoid cysts (also termed epidermal cysts, infundibular cyst)
* Pilar cysts (also termed trichelemmal cysts, isthmus-catagen cysts)
Both of the above types of cysts contain kera ...
s are present for considerable duration (normally one to several weeks).
* Congenital triangular alopecia – It is a triangular, or oval in some cases, shaped patch of hair loss in the temple area of the scalp that occurs mostly in young children. The affected area mainly contains vellus hair follicles or no hair follicles at all, but it does not expand. Its causes are unknown, and although it is a permanent condition, it does not have any other effect on the affected individuals.
* Hair growth conditions. Gradual thinning of hair with age is a natural condition known as ''involutional alopecia''. This is caused by an increasing number of hair follicle
The hair follicle is an organ found in mammalian skin. It resides in the dermal layer of the skin and is made up of 20 different cell types, each with distinct functions. The hair follicle regulates hair growth via a complex interaction between h ...
s switching from the growth, or anagen, phase into a resting phase, or telogen phase, so that remaining hairs become shorter and fewer in number. An unhealthy scalp environment can play a significant role in hair thinning by contributing to miniaturization or causing damage.
* Obesity. Obesity-induced stress, such as that induced by a high-fat diet (HFD), targets hair follicle stem cells (HFSCs) to accelerate hair thinning in mice. It is likely that similar molecular mechanism play a role in human hair loss.
Other causes of hair loss include:
* Alopecia mucinosa
* Biotinidase deficiency
Biotinidase deficiency is an autosomal recessive metabolic disorder in which biotin is not released from proteins in the diet during digestion or from normal protein turnover in the cell. This situation results in biotin deficiency.
Biotin is an ...
* Chronic inflammation
Chronic systemic inflammation (SI) is the result of release of pro-inflammatory cytokines from immune-related cells and the chronic activation of the innate immune system. It can contribute to the development or progression of certain conditions ...
* Diabetes
Diabetes, also known as diabetes mellitus, is a group of metabolic disorders characterized by a high blood sugar level ( hyperglycemia) over a prolonged period of time. Symptoms often include frequent urination, increased thirst and increased ap ...
* Pseudopelade of Brocq
Pseudopelade of Brocq is a flesh- to pink-colored, irregularly shaped alopecia that may begin in a moth-eaten pattern with eventual coalescence into larger patches of alopecia.Freedberg, et al. (2003). ''Fitzpatrick's Dermatology in General Medicin ...
* Telogen effluvium
Telogen effluvium is a scalp disorder characterized by the thinning or shedding of hair resulting from the early entry of hair in the telogen phase (the resting phase of the hair follicle).Marks, James G; Miller, Jeffery (2006). ''Lookingbill and ...
* Tufted folliculitis
Genetics
Genetic forms of localized autosomal recessive hypotrichosis include:
Pathophysiology
Hair follicle
The hair follicle is an organ found in mammalian skin. It resides in the dermal layer of the skin and is made up of 20 different cell types, each with distinct functions. The hair follicle regulates hair growth via a complex interaction between h ...
growth occurs in cycles. Each cycle consists of a long growing phase ( anagen), a short transitional phase (catagen
The growth of human hair occurs everywhere on the body except for the soles of the feet, the inside of the mouth, the lips, the backs of the ears, the palms of the hands, some external genital areas, the navel, scar tissue, and, apart from eyelas ...
) and a short resting phase (telogen
The hair follicle is an organ found in mammalian skin. It resides in the dermal layer of the skin and is made up of 20 different cell types, each with distinct functions. The hair follicle regulates hair growth via a complex interaction between ...
). At the end of the resting phase, the hair falls out (exogen) and a new hair starts growing in the follicle, beginning the cycle again.
Normally, about 40 (0–78 in men) hairs reach the end of their resting phase each day and fall out.[ ] When more than 100 hairs fall out per day, clinical hair loss (telogen effluvium
Telogen effluvium is a scalp disorder characterized by the thinning or shedding of hair resulting from the early entry of hair in the telogen phase (the resting phase of the hair follicle).Marks, James G; Miller, Jeffery (2006). ''Lookingbill and ...
) may occur. A disruption of the growing phase causes abnormal loss of anagen hairs (anagen effluvium
Anagen effluvium is the pathologic loss of anagen or growth-phase hairs. Classically, it is caused by radiation therapy to the head and systemic chemotherapy, especially with alkylating agents.Freedberg, et al. (2003). ''Fitzpatrick's Dermatology ...
).
Diagnosis
Because they are not usually associated with an increased loss rate, male-pattern and female-pattern hair loss do not generally require testing. If hair loss occurs in a young man with no family history, drug use could be the cause.
* The pull test helps to evaluate diffuse scalp hair loss. Gentle traction is exerted on a group of hairs (about 40–60) on three different areas of the scalp. The number of extracted hairs is counted and examined under a microscope. Normally, fewer than three hairs per area should come out with each pull. If more than ten hairs are obtained, the pull test is considered positive.
* The pluck test is conducted by pulling hair out "by the roots". The root of the plucked hair is examined under a microscope to determine the phase of growth, and is used to diagnose a defect of telogen, anagen, or systemic disease. Telogen hairs have tiny bulbs without sheaths at their roots. Telogen effluvium shows an increased percentage of hairs upon examination. Anagen hairs have sheaths attached to their roots. Anagen effluvium shows a decrease in telogen-phase hairs and an increased number of broken hairs.
* Scalp biopsy is used when the diagnosis is unsure; a biopsy allows for differing between scarring and nonscarring forms. Hair samples are taken from areas of inflammation, usually around the border of the bald patch.
* Daily hair counts are normally done when the pull test is negative. It is done by counting the number of hairs lost. The hair from the first morning combing or during washing should be counted. The hair is collected in a clear plastic bag for 14 days. The strands are recorded. If the hair count is >100/day, it is considered abnormal except after shampooing, where hair counts will be up to 250 and be normal.
* Trichoscopy
Trichoscopy is a method of hair and scalp evaluation and is used for diagnosing hair and scalp diseases. The method is based on dermoscopy. In trichoscopy hair and scalp structures may be visualized at many-fold magnification. Currently magnificat ...
is a noninvasive method of examining hair and scalp. The test may be performed with the use of a handheld dermoscope
Dermatoscopy also known as dermoscopy or epiluminescence microscopy, is the examination of skin lesions with a dermatoscope. It is a tool similar to a camera to allow for inspection of skin lesions unobstructed by skin surface reflections. The de ...
or a video dermoscope. It allows differential diagnosis of hair loss in most cases.
There are two types of identification tests for female pattern baldness: the Ludwig Scale and the Savin Scale. Both track the progress of diffused thinning, which typically begins on the crown of the head behind the hairline, and becomes gradually more pronounced. For male pattern baldness, the Hamilton–Norwood scale
The Hamilton–Norwood scale is used to classify the stages of male pattern baldness. The stages are described with a number from 1 to 7.
Overview
This measurement
Measurement is the quantification of attributes of an object or event, ...
tracks the progress of a receding hairline and/or a thinning crown, through to a horseshoe-shaped ring of hair around the head and on to total baldness.
In almost all cases of thinning, and especially in cases of severe hair loss, it is recommended to seek advice from a doctor or dermatologist
Dermatology is the branch of medicine dealing with the skin.''Random House Webster's Unabridged Dictionary.'' Random House, Inc. 2001. Page 537. . It is a speciality with both medical and surgical aspects. A dermatologist is a specialist medical ...
. Many types of thinning have an underlying genetic or health-related cause, which a qualified professional will be able to diagnose.
Management
Hiding hair loss
Head
One method of hiding hair loss is the comb over
A comb over or combover is a hairstyle commonly worn by balding men in which the hair is grown long and combed over the bald area to minimize the appearance of baldness. Sometimes the parting is lowered so that more hair can be used to cover the ...
, which involves restyling the remaining hair to cover the balding area. It is usually a temporary solution, useful only while the area of hair loss is small. As the hair loss increases, a comb over becomes less effective.
Another method is to wear a hat or a hairpiece such as a wig
A wig is a head or hair accessory made from human hair, animal hair, or synthetic fiber. The word wig is short for periwig, which makes its earliest known appearance in the English language in William Shakespeare's ''The Two Gentlemen of Verona' ...
or toupee. The wig is a layer of artificial or natural hair made to resemble a typical hair style. In most cases the hair is artificial. Wigs vary widely in quality and cost. In the United States, the best wigsthose that look like real haircost up to tens of thousands of dollars. Organizations also collect individuals' donations of their own natural hair to be made into wigs for young cancer
Cancer is a group of diseases involving abnormal cell growth with the potential to invade or spread to other parts of the body. These contrast with benign tumors, which do not spread. Possible signs and symptoms include a lump, abnormal b ...
patients who have lost their hair due to chemotherapy
Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemotherap ...
or other cancer treatment in addition to any type of hair loss.
Eyebrows
Though not as common as the loss of hair on the head, chemotherapy, hormone imbalance, forms of hair loss, and other factors can also cause loss of hair in the eyebrows. Loss of growth in the outer one third of the eyebrow is often associated with hypothyroidism
Hypothyroidism (also called ''underactive thyroid'', ''low thyroid'' or ''hypothyreosis'') is a disorder of the endocrine system in which the thyroid gland does not produce enough thyroid hormone. It can cause a number of symptoms, such as po ...
. Artificial eyebrows are available to replace missing eyebrows or to cover patchy eyebrows. Eyebrow embroidery is another option which involves the use of a blade to add pigment to the eyebrows. This gives a natural 3D look for those who are worried about an artificial look and it lasts for two years. Micropigmentation (permanent makeup tattooing) is also available for those who want the look to be permanent.
Medications
Treatments for the various forms of hair loss have limited success. Three medications have evidence to support their use in male pattern hair loss: minoxidil
Minoxidil, sold under the brand name Rogaine among others, is a medication used for the treatment of high blood pressure and pattern hair loss. It is an antihypertensive vasodilator. It is available as a generic medication by prescription in ora ...
, finasteride
Finasteride, sold under the brand names Proscar and Propecia among others, is a medication used to treat hair loss and benign prostatic hyperplasia (BPH) in men. It can also be used to treat excessive hair growth in women and as a part of horm ...
, and dutasteride
Dutasteride, sold under the brand name Avodart among others, is a medication primarily used to treat the symptoms of a benign prostatic hyperplasia (BPH), an enlarged prostate not associated with cancer. A few months may be required before benefi ...
. They typically work better to prevent further hair loss, than to regrow lost hair. On June 13, 2022, the U.S. Food and Drug Administration (FDA) approved Olumiant (baricitinib) for adults with severe alopecia areatal. It is the first FDA approved drug for systemic treatment, or treatment for any area of the body.
* Minoxidil
Minoxidil, sold under the brand name Rogaine among others, is a medication used for the treatment of high blood pressure and pattern hair loss. It is an antihypertensive vasodilator. It is available as a generic medication by prescription in ora ...
(Rogaine) is a nonprescription medication approved for male pattern baldness and alopecia areata. In a liquid or foam, it is rubbed into the scalp twice a day. Some people have an allergic reaction to the propylene glycol in the minoxidil solution and a minoxidil foam was developed without propylene glycol. Not all users will regrow hair. Minoxidil is also prescribed tablets to be taken orally to encourage hair regrowth although is not FDA approved to treat hair loss. The longer the hair has stopped growing, the less likely minoxidil will regrow hair. Minoxidil is not effective for other causes of hair loss. Hair regrowth can take 1 to 6 months to begin. Treatment must be continued indefinitely. If the treatment is stopped, hair loss resumes. Any regrown hair and any hair susceptible to being lost, while Minoxidil was used, will be lost. Most frequent side effects are mild scalp irritation, allergic contact dermatitis
Allergic contact dermatitis (ACD) is a form of contact dermatitis that is the manifestation of an allergic response caused by contact with a substance; the other type being irritant contact dermatitis (ICD).
Although less common than ICD, ACD is ...
, and unwanted hair in other parts of the body.
* Finasteride
Finasteride, sold under the brand names Proscar and Propecia among others, is a medication used to treat hair loss and benign prostatic hyperplasia (BPH) in men. It can also be used to treat excessive hair growth in women and as a part of horm ...
(Propecia) is used in male-pattern hair loss in a pill form, taken 1 milligram per day. It is not indicated for women and is not recommended in pregnant women (as it is known to cause birth defects in fetuses). Treatment is effective starting within 6 weeks of treatment. Finasteride causes an increase in hair retention, the weight of hair, and some increase in regrowth. Side effects in about 2% of males include decreased sex drive
Libido (; colloquial: sex drive) is a person's overall sexual drive or desire for sexual activity. Libido is influenced by biological, psychological, and social factors. Biologically, the sex hormones and associated neurotransmitters that act upo ...
, erectile dysfunction
Erectile dysfunction (ED), also called impotence, is the type of sexual dysfunction in which the penis fails to become or stay erect during sexual activity. It is the most common sexual problem in men.Cunningham GR, Rosen RC. Overview of male ...
, and ejaculatory dysfunction. Treatment should be continued as long as positive results occur. Once treatment is stopped, hair loss resumes.
* Corticosteroid
Corticosteroids are a class of steroid hormones that are produced in the adrenal cortex of vertebrates, as well as the synthetic analogues of these hormones. Two main classes of corticosteroids, glucocorticoids and mineralocorticoids, are involv ...
s injections into the scalp can be used to treat alopecia areata. This type of treatment is repeated on a monthly basis. Oral pills for extensive hair loss may be used for alopecia areata. Results may take up to a month to be seen.
* Immunosuppressant
Immunosuppressive drugs, also known as immunosuppressive agents, immunosuppressants and antirejection medications, are drugs that inhibit or prevent activity of the immune system.
Classification
Immunosuppressive drugs can be classified in ...
s applied to the scalp have been shown to temporarily reverse alopecia areata, though the side effects of some of these drugs make such therapy questionable.
* There is some tentative evidence that anthralin
Dithranol (INN) or anthralin (USAN and former BAN) is a hydroxy anthrone, anthracene derivative, medicine applied to the skin of people with psoriasis.
It is available as creams, ointment or pastes in 0.1 to 2% strengths (Drithocreme, Dithrocream, ...
may be useful for treating alopecia areata.
* Hormonal modulators (oral contraceptives Oral contraceptives, abbreviated OCPs, also known as birth control pills, are medications taken by mouth for the purpose of birth control.
Female
Two types of female oral contraceptive pill, taken once per day, are widely available:
* The combin ...
or antiandrogens such as spironolactone
Spironolactone, sold under the brand name Aldactone among others, is a medication that is primarily used to treat fluid build-up due to heart failure, liver scarring, or kidney disease. It is also used in the treatment of high blood pressure ...
and flutamide
Flutamide, sold under the brand name Eulexin among others, is a nonsteroidal antiandrogen (NSAA) which is used primarily to treat prostate cancer. It is also used in the treatment of androgen-dependent conditions like acne, excessive hair grow ...
) can be used for female-pattern hair loss associated with hyperandrogenemia.
Surgery
Hair transplantation
Hair transplantation is a surgical technique that removes hair follicles from one part of the body, called the 'donor site', to a bald or balding part of the body known as the 'recipient site'. The technique is primarily used to treat male patt ...
is usually carried out under local anesthetic
A local anesthetic (LA) is a medication that causes absence of pain sensation. In the context of surgery, a local anesthetic creates an absence of pain in a specific location of the body without a loss of consciousness, as opposed to a general an ...
. A surgeon will move healthy hair from the back and sides of the head to areas of thinning. The procedure can take between four and eight hours, and additional sessions can be carried out to make hair even thicker. Transplanted hair falls out within a few weeks, but regrows permanently within months. Hair transplants, takes tiny plugs of skin, each which contains a few hairs, and implants the plugs into bald sections. The plugs are generally taken from the back or sides of the scalp. Several transplant sessions may be necessary.
* Surgical options, such as follicle transplants, scalp flaps, and hair loss reduction, are available. These procedures are generally chosen by those who are self-conscious about their hair loss, but they are expensive and painful, with a risk of infection and scarring. Once surgery has occurred, six to eight months are needed before the quality of new hair can be assessed.
** Scalp reduction is the process is the decreasing of the area of bald skin on the head. In time, the skin on the head becomes flexible and stretched enough that some of it can be surgically removed. After the hairless scalp is removed, the space is closed with hair-covered scalp. Scalp reduction is generally done in combination with hair transplantation to provide a natural-looking hairline, especially those with extensive hair loss.
** Hairline lowering can sometimes be used to lower a high hairline secondary to hair loss, although there may be a visible scar after further hair loss.
* Wigs are an alternative to medical and surgical treatment; some patients wear a wig or hairpiece. They can be used permanently or temporarily to cover the hair loss. High-quality, natural-looking wigs and hairpieces are available.
Chemotherapy
Hypothermia cap A hypothermia cap (also referred to as cold cap or cooling cap) is a therapeutic device used to cool the human scalp. Its most prominent medical applications are in preventing or reducing alopecia in chemotherapy, and for preventing cerebral palsy ...
s may be used to prevent hair loss during some kinds of chemotherapy
Chemotherapy (often abbreviated to chemo and sometimes CTX or CTx) is a type of cancer treatment that uses one or more anti-cancer drugs (chemotherapeutic agents or alkylating agents) as part of a standardized chemotherapy regimen. Chemotherap ...
, specifically, when taxanes
Taxanes are a class of diterpenes. They were originally identified from plants of the genus ''Taxus'' (yews), and feature a taxadiene core. Paclitaxel (Taxol) and docetaxel (Taxotere) are widely used as chemotherapy agents. Cabazitaxel was FDA ap ...
or anthracyclines
Anthracyclines are a class of drugs used in cancer chemotherapy that are extracted from ''Streptomyces'' bacterium. These compounds are used to treat many cancers, including leukemias, lymphomas, breast, stomach, uterine, ovarian, bladder cance ...
are administered. It is not recommended to be used when cancer is present in the skin of the scalp or for lymphoma or leukemia. There are generally only minor side effects from scalp cooling given during chemotherapy.
Embracing baldness
Instead of attempting to conceal their hair loss, some people embrace it by either doing nothing about it or sporting a shaved head
Head shaving is a form of body modification which involves shaving the hair from a person's head. People throughout history have shaved all or part of their heads for diverse reasons including aesthetics, convenience, culture, fashion, practicality ...
. The general public became more accepting of men with shaved heads in the early 1950s, when Russian-American actor Yul Brynner
Yuliy Borisovich Briner (russian: link=no, Юлий Борисович Бринер; July 11, 1920 – October 10, 1985), known professionally as Yul Brynner, was a Russian-born actor. He was best known for his portrayal of King Mongkut in the ...
began sporting the look; the resulting phenomenon inspired many of his male fans to shave their heads. Male celebrities then continued to bring mainstream popularity to shaved heads, including athletes such as Michael Jordan
Michael Jeffrey Jordan (born February 17, 1963), also known by his initials MJ, is an American businessman and former professional basketball player. His biography on the official NBA website states: "By acclamation, Michael Jordan is the g ...
and Zinedine Zidane
Zinedine Yazid Zidane (; born 23 June 1972), popularly known as Zizou, is a French professional football manager and former player who played as an attacking midfielder. He most recently coached Spanish club Real Madrid and is one of the most ...
and actors such as Dwayne Johnson
Dwayne Douglas Johnson (born May 2, 1972), also known by his ring name The Rock, is an American actor and former professional wrestler. Widely regarded as one of the greatest professional wrestlers of all time, he was integral to the developm ...
, Ben Kingsley
Sir Ben Kingsley (born Krishna Pandit Bhanji; 31 December 1943) is an English actor. He has received various accolades throughout his career spanning five decades, including an Academy Award, a British Academy Film Award, a Grammy Award, and two ...
, and Jason Statham
Jason Statham (; born 26 July 1967) is an English actor. He is known for portraying characters in various action-thriller films who are typically tough, hardboiled, gritty, or violent.
Statham began practising Chinese martial arts, kickboxing ...
. Baldness in females, however, is still viewed as less "normal" in various parts of the world.
Alternative medicine
Dietary supplements are not typically recommended. There is only one small trial of saw palmetto
''Serenoa repens'', commonly known as saw palmetto, is the sole species currently classified in the genus ''Serenoa''. It is a small palm, growing to a maximum height around . It is endemic to the subtropical and tropical Southeastern United S ...
which shows tentative benefit in those with mild to moderate androgenetic alopecia. There is no evidence for biotin
Biotin (or vitamin B7) is one of the B vitamins. It is involved in a wide range of metabolic processes, both in humans and in other organisms, primarily related to the utilization of fats, carbohydrates, and amino acids. The name ''biotin'', bor ...
. Evidence for most other alternative medicine remedies is also insufficient. There was no good evidence for ginkgo
''Ginkgo'' is a genus of non-flowering seed plants. The scientific name is also used as the English name. The order to which it belongs, Ginkgoales, first appeared in the Permian, 270 million years ago, and is now the only living genus within ...
, aloe vera
''Aloe vera'' () is a succulent plant species of the genus ''Aloe''. It is widely distributed, and is considered an invasive species in many world regions.
An evergreen perennial, it originates from the Arabian Peninsula, but grows wild in tro ...
, ginseng
Ginseng () is the root of plants in the genus ''Panax'', such as Korean ginseng ('' P. ginseng''), South China ginseng ('' P. notoginseng''), and American ginseng ('' P. quinquefolius''), typically characterized by the presence of ginsenosides an ...
, bergamot, hibiscus
''Hibiscus'' is a genus of flowering plants in the mallow family, Malvaceae. The genus is quite large, comprising several hundred species that are native to warm temperate, subtropical and tropical regions throughout the world. Member species ...
, or sophora
''Sophora'' is a genus of about 45 species of small trees and shrubs in the pea family Fabaceae. The species have a pantropical distribution. The generic name is derived from ''sophera'', an Arabic name for a pea-flowered tree.
The genus formerl ...
as of 2011.
Many people use unproven treatments to treat hair loss. Egg oil
Egg oil ( CAS No. 8001–17–0, INCI: egg oil), also known as egg yolk oil or ovum oil, is derived from the yolk of chicken eggs consisting mainly of triglycerides with traces of lecithin, cholesterol, biotin, xanthophylls lutein and zeaxanthin ...
, in Indian, Japanese, Unani
Unani or Yunani medicine (Urdu: ''tibb yūnānī'') is Perso-Arabic traditional medicine as practiced in Muslim culture in South Asia and modern day Central Asia. Unani medicine is pseudoscientific. The Indian Medical Association describes U ...
(Roghan Baiza Murgh) and Chinese traditional medicine
Traditional medicine (also known as indigenous medicine or folk medicine) comprises medical aspects of traditional knowledge that developed over generations within the folk beliefs of various societies, including indigenous peoples, before the ...
, was traditionally used as a treatment for hair loss.
Research
Research is looking into connections between hair loss and other health issues. While there has been speculation about a connection between early-onset male pattern hair loss and heart disease, a review of articles from 1954 to 1999 found no conclusive connection between baldness and coronary artery disease. The dermatologists who conducted the review suggested further study was needed.
Environmental factors are under review. A 2007 study indicated that smoking may be a factor associated with age-related hair loss among Asian men. The study controlled for age and family history, and found statistically significant positive associations between moderate or severe male pattern hair loss and smoking status.
Vertex baldness is associated with an increased risk of coronary heart disease
Coronary artery disease (CAD), also called coronary heart disease (CHD), ischemic heart disease (IHD), myocardial ischemia, or simply heart disease, involves the reduction of blood flow to the heart muscle due to build-up of atherosclerotic pla ...
(CHD) and the relationship depends upon the severity of baldness, while frontal baldness is not. Thus, vertex baldness might be a marker of CHD and is more closely associated with atherosclerosis than frontal baldness.
Hair follicle aging
A key aspect of hair loss with age is the aging of the hair follicle. Ordinarily, hair follicle renewal is maintained by the stem cells associated with each follicle. Aging of the hair follicle appears to be primed by a sustained cellular response to the DNA damage that accumulates in renewing stem cells during aging. This damage response involves the proteolysis of type XVII collagen by neutrophil elastase
Neutrophil elastase (, ''leukocyte elastase'', ''ELANE'', ''ELA2'', ''elastase 2'', ''neutrophil'', ''elaszym'', ''serine elastase'', subtype ''human leukocyte elastase (HLE)'') is a serine proteinase in the same family as chymotrypsin and has br ...
in response to DNA damage in hair follicle stem cells. Proteolysis of collagen leads to elimination of the damaged cells and, consequently, to terminal hair follicle miniaturization.
Hedgehog signaling
In June 2022 the University of California, Irvine announced that researchers have discovered that hedgehog signaling
The Hedgehog signaling pathway is a signaling pathway that transmits information to embryonic cells required for proper cell differentiation. Different parts of the embryo have different concentrations of hedgehog signaling proteins. The pathway ...
in murine fibroblasts induces new hair growth and hair multiplication while hedgehog activation increases fibroblast heterogeneity and drives new cell states. A new signaling molecule called SCUBE3 potently stimulates hair growth and may offer a therapeutic treatment for androgenetic alopecia.
Etymology
The term ''alopecia'' () is from the Classical Greek
Ancient Greek includes the forms of the Greek language used in ancient Greece and the ancient world from around 1500 BC to 300 BC. It is often roughly divided into the following periods: Mycenaean Greek (), Dark Ages (), the Archaic peri ...
ἀλώπηξ, ''alōpēx'', meaning "fox". The origin of this usage is because this animal sheds its coat twice a year, or because in ancient Greece foxes often lost hair because of mange
Mange is a type of skin disease caused by parasitic mites. Because various species of mites also infect plants, birds and reptiles, the term "mange", or colloquially "the mange", suggesting poor condition of the skin and fur due to the infection ...
.
See also
* Alopecia in animals
* Lichen planopilaris
Lichen planus (LP) is a chronic inflammatory and immune-mediated disease that affects the skin, nails, hair, and mucous membranes. It is not an actual lichen, and is only named that because it looks like one. It is characterized by polygonal, fla ...
*
* Locks of Love
Locks of Love is a 501(c)(3) nonprofit charity that provides custom-made hair prosthetics to disadvantaged children up to the age of 21 who have suffered hair loss as a result of medical conditions, such as alopecia, burn trauma, and cancer treatm ...
– charity that provides hair prosthetics to alopecia patients
* Psychogenic alopecia
References
External links
*
{{Authority control
Conditions of the skin appendages
External signs of ageing
Hair diseases
Human hair
Radiation health effects
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