for malignant melanoma. After doing several skin
self-examinations, most people are familiar with
their usual lesions and blemishes and can quickly
identify any changes that have taken place since
the previous self-exam. A dermatologist should
evaluate any suspicious findings.
See also ACTINIC KERATOSIS; LESION; SEBORRHEIC
KERATOSIS.
skin tag See ACROCHORDON.
staphylococcal scalded skin syndrome A poten-
tially life-threatening bacterial INFECTION of the
skin that most commonly affects infants and
young children. Staphylococcus aureusis the infec-
tive agent. The infection is systemic, causing erup-
tions on the skin that give the appearance of
scalding. A single LESIONheralds the onset of the
infection, with multiple lesions rapidly emerging.
The lesions are scarlet red and quickly BLISTER. The
blisters (bullae) are very fragile and peel away
from the skin with touch. The lesions spread to be
contiguous with one another, covering large por-
tions of the body. The loss of skin exposes the
body to other pathogens that can cause complicat-
ing infections and means the body cannot main-
tain proper thermal or fluid regulation. Prompt
diagnosis and treatment with ANTIBIOTIC MEDICA-
TIONSis essential. Most children fully recover with
appropriate treatment. The infection is highly con-
tagious. Diligent HAND WASHINGis crucial for care-
givers and family members.
See also BACTERIA; BULLA; PATHOGEN; TOXIC EPIDER-
MAL NECROLYSIS; TOXIC SHOCK SYNDROME.
Stevens-Johnson syndrome See TOXIC EPIDERMAL
NECROLYSIS.
stretch marks Irregular, discolored streaks or
lines in the SKIN. Stretch marks represent, as the
name suggests, changes in the tissue structure and
appearance that result from the skin stretching
and separating from the underlying supportive tis-
sues. Such stretching most commonly occurs with
PREGNANCY, BREAST augmentation surgery, and
weight gain and loss, and affects the abdomen,
upper arms, thighs, and breasts. Early stretch
marks appear pink; mature stretch marks are gen-
erally pale. In addition to the altered pigmenta-
tion, stretch marks may have a different texture
than the surrounding skin. Stretch marks are cos-
metic and do not affect health or reflect health
conditions. Cosmetic treatments to minimize the
appearance of stretch marks include laser therapy
and topical products such as glycolic lotions and
tretinoin cream.
See also PLASTIC SURGERY.sunburn Damage to the epidermis and some-
times the dermis, the top and middle layers of the
SKIN, as a consequence of extended, unprotected
sun exposure. The sun emits several wavelengths
of ultraviolet light. Those that reach the earth’s
surface are ultraviolet A (UVA) and ultraviolet B
(UVB). Each affects the skin in different ways.
UVA activates melanocytes, the cells that produce
melanin (pigment) and may produce a thermal
(heat) response that causes the skin to turn red.
Though the skin may feel hot, this is not actually
sunburn but rather a thermal (heat) response.
Sunburn is a delayed response to UVB expo-
sure. UVB lightwaves do not activate the
melanocytes but instead affect keratinocytes.
When the epidermis (skin’s outer layer) contains
deeply pigmented keratinocytes, such as in a per-
son who has dark skin or a tan from previous sun
exposure, the pigment (melanin) absorbs the UVB
and the keratinocytes escape damage. When the
skin is light, melanin distribution is also light and
there is little absorption of UVB.200 The Integumentary System
ABCD SKIN EXAMINATION
Characteristic Normal Suspicious
A asymmetry matching halves (symmetrical) unequal or nonmatching halves (asymmetrical)
B border smooth, even edges ragged, notched, or otherwise uneven edges
C color single shade of brown varied shades of brown; multiple colors
D diameter less than one quarter inch larger than one quarter inch