Who Is Affected by Vitiligo?
About 0.5 to 1 percent of the world’s population, or as
many as 65 million people, have vitiligo. In the United
States, 1 to 2 million people have the disorder. Half
the people who have vitiligo develop it before age 20;
most develop it before their 40th birthday. The disorder
affects both sexes and all races equally; however, it is
more noticeable in people with dark skin.
Vitiligo seems to be somewhat more common in people with
certain autoimmune diseases. These autoimmune diseases
include hyperthyroidism (an overactive thyroid gland),
adrenocortical insufficiency (the adrenal gland does not
produce enough of the hormone called corticosteroid),
alopecia areata (patches of baldness), and pernicious
anemia (a low level of red blood cells caused by the
failure of the body to absorb vitamin B12 ).
Scientists do not know the reason for the association
between vitiligo and these autoimmune diseases. However,
most people with vitiligo have no other autoimmune
disease.
Vitiligo may also be hereditary; that is, it can run in
families. Children whose parents have the disorder are
more likely to develop vitiligo. In fact, 30 percent of
people with vitiligo have a family member with the
disease. However, only 5 to 7 percent of children will
get vitiligo even if a parent has it, and most people
with vitiligo do not have a family history of the
disorder.
What Are the Symptoms of Vitiligo?
People who develop vitiligo usually first notice white
patches (depigmentation) on their skin. These patches
are more commonly found on sun-exposed areas of the
body, including the hands, feet, arms, face, and lips.
Other common areas for white patches to appear are the
armpits and groin, and around the mouth, eyes, nostrils,
navel, genitals, and rectal areas.
Vitiligo generally appears in one of three patterns:
-
focal pattern—the depigmentation is limited to one
or only a few areas
-
segmental pattern—depigmented patches develop on
only one side of the body
-
generalized pattern—the most common pattern.
Depigmentation occurs symmetrically on both sides of
the body.
In addition to white patches on the skin, people with
vitiligo may have premature graying of the scalp hair,
eyelashes, eyebrows, and beard. People with dark skin
may notice a loss of color inside their mouths.
Will the Depigmented Patches Spread?
Focal pattern vitiligo and segmental vitiligo remain
localized to one part of the body and do not spread.
There is no way to predict if generalized vitiligo will
spread. For some people, the depigmented patches do not
spread. The disorder is usually progressive, however,
and over time the white patches will spread to other
areas of the body. For some people, vitiligo spreads
slowly, over many years. For other people, spreading
occurs rapidly. Some people have reported additional
depigmentation following periods of physical or
emotional stress.
How Is Vitiligo Diagnosed?
The diagnosis of vitiligo is made based on a physical
examination, medical history, and laboratory tests.
A doctor will likely suspect vitiligo if you report (or
the physical examination reveals) white patches of skin
on the body—particularly on sun-exposed areas, including
the hands, feet, arms, face, and lips. If vitiligo is
suspected, the doctor will ask about your medical
history. Important factors in the diagnosis include a
family history of vitiligo; a rash, sunburn, or other
skin trauma at the site of vitiligo 2 to 3 months before
depigmentation started; stress or physical illness; and
premature (before age 35) graying of the hair. In
addition, the doctor will ask whether you or anyone in
your family has had any autoimmune diseases, and whether
you are very sensitive to the sun.
To help confirm the diagnosis, the doctor may take a
small sample (biopsy) of the affected skin to examine
under a microscope. In vitiligo, the skin sample will
usually show a complete absence of pigment-producing
melanocytes. On the other hand, the presence of inflamed
cells in the sample may suggest that another condition
is responsible for the loss of pigmentation.
Because vitiligo may be associated with pernicious
anemia (a condition in which an insufficient amount of
vitamin B12 is absorbed from the gastrointestinal
tract) or hyperthyroidism (an overactive thyroid gland),
the doctor may also take a blood sample to check the
blood-cell count and thyroid function. For some
patients, the doctor may recommend an eye examination to
check for uveitis(inflammation of
part of the eye), which sometimes occurs with vitiligo.
A blood test to look for the presence of antinuclear
antibodies (a type of autoantibody) may also be done.
This test helps determine if the patient has another
autoimmune disease.
