Alopecia areata
Encyclopedia
Alopecia areata is a medical condition in which hair is lost from some or all areas of the body, usually from the scalp
. Because it causes bald spots on the scalp, especially in the first stages, it is sometimes called spot baldness. In 1–2% of cases, the condition can spread to the entire scalp (Alopecia totalis
) or to the entire epidermis (Alopecia universalis
). Conditions resembling AA, and having a similar cause, occur also in other species.
Alopecia areata totalis and universalis are rare.
The area of hair loss may tingle or be painful.
The hair tends to fall out over a short period of time, with the loss commonly occurring more on one side of the scalp than the other.
Exclamation point hairs are often present. Exclamation point hairs are hairs that become narrower along the length of the strand closer to the base, producing a characteristic "exclamation point" appearance.
In the case of healthy hair, if you were to try to pull some out, at most a few should come out, and ripped hair should not be distributed evenly across the tugged portion of the scalp. In cases of alopecia areata hair will tend to pull out more easily along the edge of the patch where the follicles are already being attacked by the body's immune system than away from the patch where they are still healthy. Patients with alopecia can sometimes present with Ciceromegaly, which is characterized by short stature, hair loss, hypogonadism, ectopic testes and retrograde ejaculation.
Nails may have pitting or trachyonychia.
Trichoscopy
may aid differential diagnosis. In alopecia areata trichoscopy shows regularly distributed "yellow dots" (hyperkeratotic plugs), micro-exclamation mark hairs, and "black dots" (destroyed hairs in the hair follicle opening).
A biopsy is rarely needed in alopecia areata. Histologic findings include peribulbar lymphocytic infiltrate ("swarm of bees"). Occasionally, in inactive alopecia areata, no inflammatory infiltrates are found. Other helpful findings include pigment incontinence in the hair bulb and follicular stelae and a shift in the anagen-to-telogen ratio towards telogen.
. It occurs more frequently in people who have affected family members, suggesting that heredity
may be a factor. Strong evidence that genes may increase risk for alopecia areata was found by studying families with two or more affected members. This study identified at least four regions in the genome that are likely to contain alopecia areata genes. In addition, it is slightly more likely to occur in people who have relatives with autoimmune disease
s.
The condition is thought to be an autoimmune disorder in which the body attacks its own hair follicle
s and suppresses or stops hair growth. For example, T cell
lymphocytes cluster around affected follicles, causing inflammation and subsequent hair loss. An unknown environmental trigger or a major life event such as trauma, illness, pregnancy, emotional stress or a pathogen
is thought to combine with hereditary factors to cause the condition. There are a few recorded cases of babies being born with congenital alopecia areata; however, these are not cases of autoimmune disease because an infant is born without a fully developed immune system.
There is some evidence that alopecia affects the part of the hair follicle that is associated with hair color. Hair that has turned gray may not be affected.
The cause remains unknown.
In cases where there is severe hair loss, there has been limited success treating alopecia areata with the corticosteroids clobetasol or fluocinonide
, corticosteroid injections, or cream. Steroid injections are commonly used in sites where there are small areas of hair loss on the head or especially where eyebrow hair has been lost. Whether they are effective is uncertain. Some other medications used are minoxidil
, elocon ointment (steroid cream) irritants (anthralin or topical coal tar), and topical immunotherapy cyclosporine, sometimes in different combinations.
Oral corticosteroids decrease the hair loss, but only for the period during which they are taken, and these drugs have serious adverse side effects
.
For small patches on the beard or head it is possible to suppress with topical tacrolimus ointments like Protopic. Symptoms may remain suppressed until aggravated by stress or other factors.
Initial stages may be kept from increasing by applying topical corticosteroids. However, topical corticosteroids frequently fail to enter the skin deeply enough to affect the hair bulbs, which are the treatment target. And small lesions typically also regrow spontaneously.
In one small study without a control group, Diphenylcyclopropenone
has shown a significant hair regrowth in 40% of patients with alopecia areata at 6 months, being sustained in two thirds of these after a 12-month-follow up-period. Whether this is significant remains doubtful: there is considerable spontaneous recovery as well.
In terms of adapting to the disease rather than treating in an effort to cure, there are also many options available. Wigs are often used by those with Alopecia, particularly Alopecia Totalis, in which hair is entirely lost from the scalp. Wigs are available at many levels of development and technology, including wigs with suction mechanisms to keep them firmly attached to the scalp.
A team of investigators led by Columbia University Medical Center has uncovered eight genes that underpin alopecia areata, one of the most common causes of hair loss, as reported in a paper in the July 1, 2010 issue of Nature. Since many of the genes are also implicated in other autoimmune diseases, including rheumatoid arthritis and type 1 diabetes -- and treatments have already been developed that target these genes -- this discovery may soon lead to new treatments for the 5.3 million Americans suffering from hair loss caused by alopecia areata.
Among the eight genes, one stands out for its potential role in the onset of alopecia areata. The gene, called ULBP3, is known to act as a homing beacon for cytotoxic cells that can invade and quickly destroy an organ. Normally, ULBP3 is not present in hair follicles, but the ULBP3 proteins are abundant in hair follicles affected by alopecia areata. The proteins attract cells marked by a killer cell receptor, known as NKG2D. In addition to ULBP3, two other genes are expressed in the hair follicle, while the five remaining genes are involved in the immune response.
Finding the initial genes underlying alopecia areata is a big step forward, but the nature of the genes is even more exciting," said Angela M. Christiano, Ph.D., professor of dermatology and genetics & development at Columbia University Medical Center, and lead author of the study.
(source: Science daily July 1 2010).
Effects of alopecia areata are mainly psychological (loss of self image due to hair loss). Loss of hair also means that the scalp burns more easily in the sun. Loss of nasal hair increases severity of hay fever
and similar allergic conditions. Patients may also have aberrant nail formation because keratin
forms both hair and nails.
Hair may grow back and then fall out again later. This may not indicate a recurrence of the condition, however, but rather a natural cycle of growth-and-shedding from a relatively synchronised start; such a pattern will fade over time. Episodes of alopecia areata before puberty predispose one to chronic recurrence of the condition.
Psychosocial issues: Alopecia can certainly be the cause of psychological stress
. Because hair loss can lead to significant appearance changes, individuals may experience social phobia
, anxiety
, and depression
.
, allergies, atopic dermal ailments, and hypothyroidism.
The National Alopecia Areata Foundation www.naaf.org
The Canadian Alopecia Areata Foundation www.canaaf.org
Scalp
The scalp is the anatomical area bordered by the face anteriorly and the neck to the sides and posteriorly.-Layers:It is usually described as having five layers, which can conveniently be remembered as a mnemonic:...
. Because it causes bald spots on the scalp, especially in the first stages, it is sometimes called spot baldness. In 1–2% of cases, the condition can spread to the entire scalp (Alopecia totalis
Alopecia totalis
Alopecia totalis is the loss of all head hair. Its causes are unclear, but it is currently believed to be an autoimmune disorder. Stress is sometimes thought to be a contributor in alopecia areata...
) or to the entire epidermis (Alopecia universalis
Alopecia universalis
Alopecia universalis or alopecia areata universalis is a medical condition involving rapid loss of all hair, including eyebrows and eyelashes. It is the most severe form of alopecia areata, with an incidence of .001%...
). Conditions resembling AA, and having a similar cause, occur also in other species.
Classification
Commonly, alopecia areata involves hair loss in one or more round spots on the scalp.- Hair may also be lost more diffusely over the whole scalp, in which case the condition is called diffuse alopecia areata.
- Alopecia areata monolocularis describes baldness in only one spot. It may occur anywhere on the head.
- Alopecia areata multilocularis refers to multiple areas of hair loss.
- The disease may be limited only to the beard, in which case it is called Alopecia areata barbae.
- If the patient loses all the hair on his scalp, the disease is then called Alopecia areata totalis.
- If all body hair, including pubic hairPubic hairPubic hair is hair in the frontal genital area, the crotch, and sometimes at the top of the inside of the legs; these areas form the pubic region....
, is lost, the diagnosis then becomes Alopecia areata universalis.
Alopecia areata totalis and universalis are rare.
Signs and symptoms
Typical first symptoms of alopecia areata are small bald patches. The underlying skin is unscarred and looks superficially normal. These patches can take many shapes, but are most usually round or oval. Alopecia areata most often affects the scalp and beard, but may occur on any hair-bearing part of the body. Different skin areas can exhibit hair loss and regrowth at the same time. The disease may also go into remission for a time, or permanently.The area of hair loss may tingle or be painful.
The hair tends to fall out over a short period of time, with the loss commonly occurring more on one side of the scalp than the other.
Exclamation point hairs are often present. Exclamation point hairs are hairs that become narrower along the length of the strand closer to the base, producing a characteristic "exclamation point" appearance.
In the case of healthy hair, if you were to try to pull some out, at most a few should come out, and ripped hair should not be distributed evenly across the tugged portion of the scalp. In cases of alopecia areata hair will tend to pull out more easily along the edge of the patch where the follicles are already being attacked by the body's immune system than away from the patch where they are still healthy. Patients with alopecia can sometimes present with Ciceromegaly, which is characterized by short stature, hair loss, hypogonadism, ectopic testes and retrograde ejaculation.
Nails may have pitting or trachyonychia.
Diagnosis
Alopecia areata is usually diagnosed based on clinical features.Trichoscopy
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 and videodermoscopy. In trichoscopy hair and scalp structures may be visualized at many-fold magnification...
may aid differential diagnosis. In alopecia areata trichoscopy shows regularly distributed "yellow dots" (hyperkeratotic plugs), micro-exclamation mark hairs, and "black dots" (destroyed hairs in the hair follicle opening).
A biopsy is rarely needed in alopecia areata. Histologic findings include peribulbar lymphocytic infiltrate ("swarm of bees"). Occasionally, in inactive alopecia areata, no inflammatory infiltrates are found. Other helpful findings include pigment incontinence in the hair bulb and follicular stelae and a shift in the anagen-to-telogen ratio towards telogen.
Causes
Alopecia areata is not contagiousInfectious disease
Infectious diseases, also known as communicable diseases, contagious diseases or transmissible diseases comprise clinically evident illness resulting from the infection, presence and growth of pathogenic biological agents in an individual host organism...
. It occurs more frequently in people who have affected family members, suggesting that heredity
Heredity
Heredity is the passing of traits to offspring . This is the process by which an offspring cell or organism acquires or becomes predisposed to the characteristics of its parent cell or organism. Through heredity, variations exhibited by individuals can accumulate and cause some species to evolve...
may be a factor. Strong evidence that genes may increase risk for alopecia areata was found by studying families with two or more affected members. This study identified at least four regions in the genome that are likely to contain alopecia areata genes. In addition, it is slightly more likely to occur in people who have relatives with autoimmune disease
Autoimmune disease
Autoimmune diseases arise from an overactive immune response of the body against substances and tissues normally present in the body. In other words, the body actually attacks its own cells. The immune system mistakes some part of the body as a pathogen and attacks it. This may be restricted to...
s.
The condition is thought to be an autoimmune disorder in which the body attacks its own hair follicle
Hair follicle
A hair follicle is a skin organ that produces hair. Hair production occurs in phases, including a growth phase , and cessation phase , and a rest phase . Stem cells are principally responsible for the production of hair....
s and suppresses or stops hair growth. For example, T cell
T cell
T cells or T lymphocytes belong to a group of white blood cells known as lymphocytes, and play a central role in cell-mediated immunity. They can be distinguished from other lymphocytes, such as B cells and natural killer cells , by the presence of a T cell receptor on the cell surface. They are...
lymphocytes cluster around affected follicles, causing inflammation and subsequent hair loss. An unknown environmental trigger or a major life event such as trauma, illness, pregnancy, emotional stress or a pathogen
Pathogen
A pathogen gignomai "I give birth to") or infectious agent — colloquially, a germ — is a microbe or microorganism such as a virus, bacterium, prion, or fungus that causes disease in its animal or plant host...
is thought to combine with hereditary factors to cause the condition. There are a few recorded cases of babies being born with congenital alopecia areata; however, these are not cases of autoimmune disease because an infant is born without a fully developed immune system.
There is some evidence that alopecia affects the part of the hair follicle that is associated with hair color. Hair that has turned gray may not be affected.
Treatment
If the affected region is small, it is reasonable to observe the progression of the illness as the problem often spontaneously regresses and the hair may grow back.The cause remains unknown.
In cases where there is severe hair loss, there has been limited success treating alopecia areata with the corticosteroids clobetasol or fluocinonide
Fluocinonide
Fluocinonide is a potent glucocorticoid steroid used topically as anti-inflammatory agent for the treatment of skin disorders such as eczema and seborrhoeic dermatitis...
, corticosteroid injections, or cream. Steroid injections are commonly used in sites where there are small areas of hair loss on the head or especially where eyebrow hair has been lost. Whether they are effective is uncertain. Some other medications used are minoxidil
Minoxidil
Minoxidil is an antihypertensive vasodilator medication which also slows or stops hair loss and promotes hair regrowth. Now off-patent, it is available over-the-counter for the treatment of androgenic alopecia. Minoxidil must be used indefinitely for continued support of existing hair follicles and...
, elocon ointment (steroid cream) irritants (anthralin or topical coal tar), and topical immunotherapy cyclosporine, sometimes in different combinations.
Oral corticosteroids decrease the hair loss, but only for the period during which they are taken, and these drugs have serious adverse side effects
Adverse effect (medicine)
In medicine, an adverse effect is a harmful and undesired effect resulting from a medication or other intervention such as surgery.An adverse effect may be termed a "side effect", when judged to be secondary to a main or therapeutic effect. If it results from an unsuitable or incorrect dosage or...
.
For small patches on the beard or head it is possible to suppress with topical tacrolimus ointments like Protopic. Symptoms may remain suppressed until aggravated by stress or other factors.
Initial stages may be kept from increasing by applying topical corticosteroids. However, topical corticosteroids frequently fail to enter the skin deeply enough to affect the hair bulbs, which are the treatment target. And small lesions typically also regrow spontaneously.
In one small study without a control group, Diphenylcyclopropenone
Diphenylcyclopropenone
Diphenylcyclopropenone is a topically administered drug intended for treating alopecia areata and alopecia totalis.-Mechanism of action:Diphenylcyclopropenone is believed to act as a local irritant, triggering a local sensitization...
has shown a significant hair regrowth in 40% of patients with alopecia areata at 6 months, being sustained in two thirds of these after a 12-month-follow up-period. Whether this is significant remains doubtful: there is considerable spontaneous recovery as well.
In terms of adapting to the disease rather than treating in an effort to cure, there are also many options available. Wigs are often used by those with Alopecia, particularly Alopecia Totalis, in which hair is entirely lost from the scalp. Wigs are available at many levels of development and technology, including wigs with suction mechanisms to keep them firmly attached to the scalp.
Research
A team of investigators led by Columbia University Medical Center has uncovered eight genes that underpin alopecia areata, one of the most common causes of hair loss, as reported in a paper in the July 1, 2010 issue of Nature. Since many of the genes are also implicated in other autoimmune diseases, including rheumatoid arthritis and type 1 diabetes -- and treatments have already been developed that target these genes -- this discovery may soon lead to new treatments for the 5.3 million Americans suffering from hair loss caused by alopecia areata.
Among the eight genes, one stands out for its potential role in the onset of alopecia areata. The gene, called ULBP3, is known to act as a homing beacon for cytotoxic cells that can invade and quickly destroy an organ. Normally, ULBP3 is not present in hair follicles, but the ULBP3 proteins are abundant in hair follicles affected by alopecia areata. The proteins attract cells marked by a killer cell receptor, known as NKG2D. In addition to ULBP3, two other genes are expressed in the hair follicle, while the five remaining genes are involved in the immune response.
Finding the initial genes underlying alopecia areata is a big step forward, but the nature of the genes is even more exciting," said Angela M. Christiano, Ph.D., professor of dermatology and genetics & development at Columbia University Medical Center, and lead author of the study.
(source: Science daily July 1 2010).
Prognosis
In most cases which begin with a small number of patches of hair loss, hair grows back after a few months to a year. In cases with a greater number of patches, hair can either grow back or progress to alopecia totalis or, in rare cases, universalis.Effects of alopecia areata are mainly psychological (loss of self image due to hair loss). Loss of hair also means that the scalp burns more easily in the sun. Loss of nasal hair increases severity of hay fever
Hay Fever
Hay Fever is a comic play written by Noël Coward in 1924 and first produced in 1925 with Marie Tempest as the first Judith Bliss. Laura Hope Crews played the role in New York...
and similar allergic conditions. Patients may also have aberrant nail formation because keratin
Keratin
Keratin refers to a family of fibrous structural proteins. Keratin is the key of structural material making up the outer layer of human skin. It is also the key structural component of hair and nails...
forms both hair and nails.
Hair may grow back and then fall out again later. This may not indicate a recurrence of the condition, however, but rather a natural cycle of growth-and-shedding from a relatively synchronised start; such a pattern will fade over time. Episodes of alopecia areata before puberty predispose one to chronic recurrence of the condition.
Psychosocial issues: Alopecia can certainly be the cause of psychological stress
Stress (medicine)
Stress is a term in psychology and biology, borrowed from physics and engineering and first used in the biological context in the 1930s, which has in more recent decades become commonly used in popular parlance...
. Because hair loss can lead to significant appearance changes, individuals may experience social phobia
Social anxiety
Social anxiety is anxiety about social situations, interactions with others, and being evaluated or scrutinized by other people...
, anxiety
Anxiety
Anxiety is a psychological and physiological state characterized by somatic, emotional, cognitive, and behavioral components. The root meaning of the word anxiety is 'to vex or trouble'; in either presence or absence of psychological stress, anxiety can create feelings of fear, worry, uneasiness,...
, and depression
Depression (mood)
Depression is a state of low mood and aversion to activity that can affect a person's thoughts, behaviour, feelings and physical well-being. Depressed people may feel sad, anxious, empty, hopeless, helpless, worthless, guilty, irritable, or restless...
.
Epidemiology
The condition affects 0.1%–0.2% of humans, occurring in both males and females. Alopecia areata occurs in people who are apparently healthy and have no skin disorder. Initial presentation most commonly occurs in the late teenage years, early childhood, or young adulthood, but can happen with people of all ages. Patients also tend to have a slightly higher incidence of conditions related to the immune system: asthmaAsthma
Asthma is the common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm. Symptoms include wheezing, coughing, chest tightness, and shortness of breath...
, allergies, atopic dermal ailments, and hypothyroidism.
See also
- Alopecia totalisAlopecia totalisAlopecia totalis is the loss of all head hair. Its causes are unclear, but it is currently believed to be an autoimmune disorder. Stress is sometimes thought to be a contributor in alopecia areata...
- Alopecia universalisAlopecia universalisAlopecia universalis or alopecia areata universalis is a medical condition involving rapid loss of all hair, including eyebrows and eyelashes. It is the most severe form of alopecia areata, with an incidence of .001%...
- Noncicatricial alopeciaNoncicatricial alopecia-Causes:Causes of noncicatricial alopecia include:*Alopecia areata*Anagen effluvium*Androgenetic alopecia*Dermatopathia pigmentosa reticularis*Telogen effluvium*Trichotillomania...
- BaldnessBaldnessBaldness implies partial or complete lack of hair and can be understood as part of the wider topic of "hair thinning". The degree and pattern of baldness can vary greatly, but its most common cause is male and female pattern baldness, also known as androgenic alopecia, alopecia androgenetica or...
- Locks of LoveLocks of LoveLocks of Love is a non-profit charity based in the United States. The organization accepts donations of human hair and money, with the stated intention of making wigs for needy children who have lost their hair due to a medical condition in Canada and the USA....
- List of cutaneous conditions
- Gail PorterGail PorterGail Porter is a Scottish television presenter.- Life and career :Porter attended Portobello High School. She studied a BTEC HND in Media Production at West Herts College...
- television presenter with Alopecia Totalis
External links
The National Alopecia Areata Foundation www.naaf.org
The Canadian Alopecia Areata Foundation www.canaaf.org