Alopecia Areata (AA),
Spot Baldness or
'Davey Kirts syndrome'
is an autoimmune disease in which hair is lost from some or all areas of the body, usually from the scalp due to the body's failure to recognize its own body cells and destroys its own tissue as if it were an invader.
Often it causes bald spots on the scalp, especially in the first stages.
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.
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. Ophiasis refers to hair loss in the shape of a wave at the circumference of the head.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 the scalp, the disease is then called alopecia totalis.
If all body hair, including pubic hair, is lost, the diagnosis then becomes alopecia universalis.
Alopecia areata totalis and universalis are rare.
Signs and symptoms
Typical first symptoms of AA 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. AA 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 may be permanent.
It is common in children.
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, narrower along the length of the strand closer to the base, producing a characteristic "exclamation point" appearance, are often present.
When healthy hair is pulled 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 AA, 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.
Nails may have pitting or trachyonychia.
Diagnosis
Alopecia areata is usually diagnosed based on clinical features.
Trichoscopy may aid differential diagnosis.
A biopsy is rarely needed in AA.
Causes
Alopecia areata is not contagious.
It occurs more frequently in people who have affected family members, suggesting heredity may be a factor. Strong evidence of genetic association with increased risk for AA was found by studying families with two or more affected members.
In addition, it is slightly more likely to occur in people who have relatives with autoimmune diseases.
The condition is thought to be a systemic autoimmune disorder in which the body attacks its own anagen hair follicles and suppresses or stops hair growth. For example, T cell lymphocytes cluster around affected follicles, causing inflammation and subsequent hair loss.
A few cases of babies being born with congenital AA have been reported, but these are not cases of autoimmune disease, because an infant is born without a definitely developed immune system.
Endogenous retinoids metabolic defect is a key part of the pathogenesis of the AA.
Iron may play a role in some cases of hair loss.
Treatment
If the affected region is small, it is reasonable to only observe the progression of the illness, as the problem often spontaneously regresses and the hair may grow back.
In cases of severe hair loss, limited success has been shown from treating AA with the corticosteroids clobetasol or fluocinonide, corticosteroid injections, or cream. The cream however is not as effective and it takes longer in order to see results.
Steroid injections are commonly used in sites where the areas of hair loss on the head are small or especially where eyebrow hair has been lost. Whether they are effective is uncertain. Some other medications used are
minoxidil,
Elocon (mometasone) ointment (steroid cream), irritants (anthralin or topical coal tar),
and topical immunotherapy cyclosporin, sometimes in different combinations. 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. Oral corticosteroids decrease the hair loss, but only for the period during which they are taken, and these drugs have serious adverse side effects.
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 AA totalis or, in rare cases, AA universalis.
Effects of AA are mainly psychological
(loss of self-image due to hair loss). Loss of hair also means the scalp burns more easily in the sun.
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 AA before puberty predispose one to chronic recurrence of the condition.
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.
Spot Baldness or
'Davey Kirts syndrome'
is an autoimmune disease in which hair is lost from some or all areas of the body, usually from the scalp due to the body's failure to recognize its own body cells and destroys its own tissue as if it were an invader.
Often it causes bald spots on the scalp, especially in the first stages.
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.
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. Ophiasis refers to hair loss in the shape of a wave at the circumference of the head.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 the scalp, the disease is then called alopecia totalis.
If all body hair, including pubic hair, is lost, the diagnosis then becomes alopecia universalis.
Alopecia areata totalis and universalis are rare.
Signs and symptoms
Typical first symptoms of AA 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. AA 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 may be permanent.
It is common in children.
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, narrower along the length of the strand closer to the base, producing a characteristic "exclamation point" appearance, are often present.
When healthy hair is pulled 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 AA, 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.
Nails may have pitting or trachyonychia.
Diagnosis
Alopecia areata is usually diagnosed based on clinical features.
Trichoscopy may aid differential diagnosis.
A biopsy is rarely needed in AA.
Causes
Alopecia areata is not contagious.
It occurs more frequently in people who have affected family members, suggesting heredity may be a factor. Strong evidence of genetic association with increased risk for AA was found by studying families with two or more affected members.
In addition, it is slightly more likely to occur in people who have relatives with autoimmune diseases.
The condition is thought to be a systemic autoimmune disorder in which the body attacks its own anagen hair follicles and suppresses or stops hair growth. For example, T cell lymphocytes cluster around affected follicles, causing inflammation and subsequent hair loss.
A few cases of babies being born with congenital AA have been reported, but these are not cases of autoimmune disease, because an infant is born without a definitely developed immune system.
Endogenous retinoids metabolic defect is a key part of the pathogenesis of the AA.
Iron may play a role in some cases of hair loss.
Treatment
If the affected region is small, it is reasonable to only observe the progression of the illness, as the problem often spontaneously regresses and the hair may grow back.
In cases of severe hair loss, limited success has been shown from treating AA with the corticosteroids clobetasol or fluocinonide, corticosteroid injections, or cream. The cream however is not as effective and it takes longer in order to see results.
Steroid injections are commonly used in sites where the areas of hair loss on the head are small or especially where eyebrow hair has been lost. Whether they are effective is uncertain. Some other medications used are
minoxidil,
Elocon (mometasone) ointment (steroid cream), irritants (anthralin or topical coal tar),
and topical immunotherapy cyclosporin, sometimes in different combinations. 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. Oral corticosteroids decrease the hair loss, but only for the period during which they are taken, and these drugs have serious adverse side effects.
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 AA totalis or, in rare cases, AA universalis.
Effects of AA are mainly psychological
(loss of self-image due to hair loss). Loss of hair also means the scalp burns more easily in the sun.
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 AA before puberty predispose one to chronic recurrence of the condition.
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.
