V

vesicle A small, blisterlike LESIONon the SKINthat
contains serous fluid. Vesicles typically occur in
clusters and indicate INFECTION, such as with HERPES
SIMPLEX VIRUS(HSV), or irritation, such as results
from contact with poison ivy. Skin vesicles often
hurt or itch. Treatment may include topical med-
ications to relieve discomfort, with oral ANALGESIC
MEDICATIONS(PAINrelievers) or ANTIHISTAMINE MED-
ICATIONS(to relieve itching) as necessary. Vesicles
begin to recede and heal when the underlying cir-
cumstance causing them begins to resolve. Vesicles
usually do not rupture or tear. During HEALINGthe
body reabsorbs the serous fluid they contain, giv-
ing the appearance that the vesicles wither away
until all that remains is a thin crust that eventu-
ally falls off.
In other contexts within the human body, a
vesicle is a small saclike or pocketlike structure in
an organ, such as the seminal vesicles in the male
reproductive system.
See also BLISTER; BULLA.

vitiligo A condition of hypopigmentation in
which melanocytes die in patches of SKIN, leaving
macules that are pale and depigmented. Dermatol-
ogists believe vitiligo is an autoimmune disorder
in which the IMMUNE SYSTEMproduces antibodies
that attack melanocytes, the skin cells responsible
for producing pigment. Vitiligo affects people of all
races and ethic backgrounds, though is more con-
spicuous in people who have darker skin.
There appears to be no pattern to the presenta-
tion of vitiligo, which may affect small areas or
nearly the entire skin surface. The depigmented
areas have no other symptoms—that is, they do
not cause itching or PAIN. Vitiligo occurs more fre-
quently in people who have other AUTOIMMUNE
DISORDERSsuch asALOPECIA AREATA. Vitiligo is also

associated with ADDISON’S DISEASE(a disorder of

the ADRENAL GLANDS), HYPERTHYROIDISM, DIABETES,

and pernicious ANEMIA.

Symptoms and Diagnostic Path

In most people who develop vitiligo, the areas of

depigmentation generally appear slowly and start

with small patches of skin. Some people do not

develop more than a few such patches, while

other people eventually develop large and numer-

ous patches of depigmentation. In most people,

the depigmentation is roughly symmetrical on

both sides of the body, though in some people it

affects only one side. The appearance of the depig-

mented areas is generally diagnostic as this is a

unique symptom of vitiligo. The most common

sites for depigmentation are the face, hands, arms,

legs, and genitals.

Often there was a precipitating factor, such as a

severe SUNBURNor other trauma to the skin, within

several months of the start of symptoms. Serious

physical injury or illness may also precipitate

symptoms. The dermatologist may biopsy a repre-

sentative LESIONto rule out other causes. Some-

times blood tests will show the presence of

antibodies, which strongly supports the diagnosis

of an autoimmune disorder.

Treatment Options and Outlook

The cosmetic aspects of vitiligo are often the most

disturbing feature of vitiligo for people who have

the disorder, and most treatments target cosmetic

improvement. Most aim to slow the progression of

the depigmentation or to darken the appearance

of depigmented areas and include topical CORTICO-

STEROID MEDICATIONS, micropigmentation (thera-

peutic tattooing), and psoralen plus ultraviolet A

(PUVA) PHOTOTHERAPY. Skin grafts are sometimes

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