Facts on File Encyclopedia of Health and Medicine

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Minoxidil and finasteride can cause
serious BIRTH DEFECTS when they enter
the system of a woman who is preg-
nant. Women of childbearing age gener-
ally should not use or handle these
products.

Hair replacement methods surgically relocate
scalp SKINwith abundant, productive hair follicles
to areas of the scalp where there is hair loss.
Though these methods cannot restore hair growth
to its previous patterns and thickness, they can
provide satisfactory results for many people. The
color and consistency of the hair influences the
success of hair replacement. As well, the scalp
must contain adequate areas of productive hair
follicles to serve as donor sites.


Risk Factors and Preventive Measures
Risk factors for alopecia include AUTOIMMUNE DISOR-
DERS, toxic exposures, stress, heredity, and aging.
Efforts to maintain healthy skin help support pro-
ductive hair growth though cannot prevent most
forms of alopecia. Treating any underlying condi-
tion that causes alopecia often results in the
return of hair.
See also FOLICULITIS; HIRSUTISM; LICHEN PLANUS;
SCAR; STRESS AND STRESS MANAGEMENT; TINEA INFEC-
TIONS.


alopecia areata A form of HAIRloss (ALOPECIA)
that results from an autoimmune disorder in
which the IMMUNE SYSTEMattacks clusters of hair
follicles, halting hair growth. The clusters typically
appear as circular patches of hairless SKIN, which
are most noticeable when they occur on the scalp
though can occur anywhere on the body. Hair
growth within the affected follicles may remain
interrupted for months to years; the timing and
pattern of attacks seem to be random. Hair growth
will eventually resume without treatment, though
sometimes years after symptoms first begin. The
extent of hair loss varies widely among individu-
als, ranging from a few isolated patches to the
entire scalp or total body. Some people also expe-
rience small pits, called stippling, in their finger-
nails and toenails. Alopecia areata can affect


people of any age and is more common in people
who have other AUTOIMMUNE DISORDERS.
Researchers suspect an interaction between
genetic and environmental factors is responsible
for alopecia areata, though they do not yet under-
stand the precise mechanisms. Alopecia areata
does not affect health in any way other than hair
growth; however, the cosmetic result (particularly
scalp involvement) often distresses people who
have the condition. Treatments to stimulate folli-
cle activity sometimes can restore normal hair pat-
terns when hair loss is mild to moderate. Cosmetic
solutions such as wigs or hairpieces may produce
more satisfactory results than medical interven-
tions when the affected areas are extensive.

THERAPIES FOR ALOPECIA AREATA
site-specific cortisone injections oralCORTICOSTEROID
topical minoxidil MEDICATIONS
topical IMMUNOTHERAPY topical anthralin
wigs and hairpieces

See also PSORIASIS.

angioma A noncancerous tumor formed of BLOOD
vessels (hemangioma) or LYMPH VESSELS(lymphan-
gioma). Angiomas visible on the SKINare common
and may appear as circular, red growths (cherry
angiomas) or weblike networks of blood vessels just
beneath the surface of the skin (spider angiomas).
Angiomas generally remain small and seldom pre-
sent health complications. Because it contains such
a rich blood supply an angioma may bleed pro-
fusely when cut or in a location that receives fre-
quent irritation such as from clothing that rubs or
constricts it. The dermatologist may remove an
angioma that often bleeds or that the person finds
cosmetically unacceptable. Common methods of
removal include electrical desiccation (applying a
slight electrical current to the angioma) and liquid
nitrogen (which freezes the angioma). Angiomas
occur more frequently in older adults (beyond age
50), though can develop at any age.
See also ARTERIOVENOUS MALFORMATION (AV M);
TELANGIECTASIS; VARICOSE VEINS.

athlete’s foot See TINEA INFECTIONS.

138 The Integumentary System

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