What Is Alopecia Areata?
Alopecia areata is considered an
autoimmune disease, in which the immune system, which is
designed to protect the body from foreign invaders such as
viruses and bacteria, mistakenly attacks the hair follicles,
the tiny cup-shaped structures from which hairs grow. This
can lead to hair loss on the scalp and elsewhere.
In most cases, hair falls out in
small, round patches about the size of a quarter. In many
cases, the disease does not extend beyond a few bare
patches. In some people, hair loss is more extensive.
Although uncommon, the disease can progress to cause total
loss of hair on the head (referred to as alopecia areata
totalis) or complete loss of hair on the head, face, and
body (alopecia areata universalis).
What Causes It?
In alopecia areata, immune system
cells called white blood cells attack the rapidly growing
cells in the hair follicles that make the hair. The affected
hair follicles become small and drastically slow down hair
production. Fortunately, the stem cells that continually
supply the follicle with new cells do not seem to be
targeted. So the follicle always has the potential to regrow
Scientists do not know exactly why
the hair follicles undergo these changes, but they suspect
that a combination of genes may predispose some people to
the disease. In those who are genetically predisposed, some
type of trigger--perhaps a virus or something in the
person's environment--brings on the attack against the hair
Who Is Most Likely To Get It?
Alopecia areata affects an estimated
four million Americans of both sexes and of all ages and
ethnic backgrounds. It often begins in childhood.
If you have a close family member
with the disease, your risk of developing it is slightly
increased. If your family member lost his or her first patch
of hair before age 30, the risk to other family members is
greater. Overall, one in five people with the disease have a
family member who has it as well.
Source: Adapted from National
Institute of Arthritis and Musculoskeletal and Skin Diseases
Part 1: What is alopecia areata?
Part 2: Is alopecia heredity?
Part 3: Is my hair loss a serious disease?
Part 4: Treatments for alopecia
Part 5: Will my hair grow back?
Part 6: How can I cope with alopecia?
Part 7: What can I expect later in life?