hives). Wheals associated with urticaria typically
itch, sometimes intensely. Wheals usually do not
rupture or tear, and gradually fade to smooth, red
areas (macules) before disappearing entirely as the
body absorbs the fluid they contain.
See alsoBULLA; MACULE; PRURITUS.
whitlow An INFECTIONat the end of the finger, or
less commonly the end of a toe, that contains pus
and is very painful. The area is inflamed, enlarged,
erythematous (reddened), and often oozing. A
common cause of whitlow is infection with the
HERPES SIMPLEX VIRUS(HSV), conveyed to the finger
via contact with infectious secretions from oral
herpes infections or genital herpes lesions. Some
doctors use the terms whitlowand paronychiainter-
changeably, whereas others use whitlow to refer
to HSV infection and paronychia to refer to bacte-
rial infection. It is important to distinguish
between the causes of the infection as the treat-
ment approach is different. Herpetic whitlow fea-
tures the vesicles characteristic of HSV infection,
and treatment is primarily to relieve symptoms.
Bacterial whitlow lacks vesicles and treatment
requires ANTIBIOTIC MEDICATIONS.
See also ABSCESS; BACTERIA.
wrinkles Furrows or channels in the SKIN, typi-
cally resulting from repeated movements, such as
facial expressions (for example, crow’s feet and
laugh lines), or from long-term exposure to sun
and wind. Aging is the single-most significant fac-
tor that causes wrinkles. Wrinkles increase with
age as the skin loses collagen and subsequently
resiliency. As well, the skin and the cutaneous tis-
sue layer that supports it both thin, providing less
support.
People who have light-colored skin tend to
have more wrinkles than people who have darker
skin. Smoking ages the skin considerably, increas-
ing the depth and number of wrinkles. Extensive
wrinkles may signal substantial sun damage that is
an alert for SKIN CANCER. Rapid or major weight
loss also causes wrinkles, as the skin that stretched
to accommodate the extra weight suddenly has no
underlying support so it sags, bags, and wrinkles.
Prematurely wrinkled skin has less ability to pro-
tect itself from the sun because its layers are thin-
ner and contain fewer cells, which means less
melanin to shield the skin from ultraviolet radia-
tion.
For many people, wrinkles are cosmetically
undesirable. Dermatologists offer a number of
solutions to reduce the appearance of wrinkles.
These include- For a CHEMICAL PEEL, the dermatologist applies a
caustic solution to the skin, causing the epider-
mis, and in a deep chemical peel the dermis, to
slough away. The new skin that forms beneath
is tighter, pulling the surface of the skin
smooth. - For DERMABRASION, the dermatologist mechani-
cally removes the top layers of skin (with local
Anesthesia), using a device similar to a small
grinder or sander to strip away the epidermis. - For LASER SKIN RESURFACING, the dermatologist
uses a heat laser to “burn” away the top layers
of the skin. This technique allows the dermatol-
ogist to precisely control the depth and extent
of skin removal as well as to target some areas
for deeper penetration and others for lighter
penetration. - For BOTULINUM THERAPY, the dermatologist injects
purified botulinum toxin into the muscles
beneath the skin. This paralyzes them and
keeps them from contracting. The paralysis
keeps the person from forming wrinkles. Botu-
linum therapy lasts three to four months on
average, depending on the location and the
person’s natural skin-aging tendencies. - For BLEPHAROPLASTYand RHYTIDOPLASTY, a sur-
geon performs cosmetic surgery operations to
remove wrinkles and tighten the skin around
the eyes (blepharoplasty) and the overall face
(rhytidoplasty).
Though it is not possible to totally prevent
wrinkles because they develop as a function of
aging, it is possible to reduce their numbers and
effects. Preventive measures include- drink plenty of water to keep the skin well
hydrated - use topical moisturizers and emollients to hold
moisture in the skin
210 The Integumentary System