C h a p t e r 4 6
Disorders of Skin Integrity and Function
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telangiectases found on basal cell carcinomas. Later,
lesions grow outward, show large ulcerations, and have
persistent crusts and raised erythematous borders. The
lesions occur on sun-exposed areas of the skin, particu-
larly the nose, forehead, helix of the ear, lower lip, and
back of the hand. Invasive squamous cell carcinoma has
the potential to recur and metastasize. Chief among the
risk factors for tumor recurrence and metastasis are the
size and location of the tumor.
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Large lesions (>2 cm in
diameter), tumors of the lip and ear, tumors arising in
injured or chronically diseased skin, and rapidly grow-
ing lesions are at particular risk.
Treatment measures are aimed at the removal of all
cancerous tissue using methods such as electrosurgery,
excision surgery, chemosurgery, or radiation therapy.
After treatment, the person is observed for the remain-
der of his or her life for signs of recurrence.
Age-Related Skin Conditions
Some skin problems occur in specific age groups. These
include not only birthmarks, but also disorders charac-
teristic of childhood, as well as skin changes common in
the elderly.
Skin Manifestations of Infancy
and Childhood
Infancy connotes the image of perfect, unblemished
skin. For the most part, this is true. However, several
acquired skin conditions, including diaper dermatitis,
prickly heat, and cradle cap, are relatively common
in infants. Moreover, congenital skin lesions, such as
Mongolian spots, hemangiomas, and nevi, are associ-
ated with the neonatal period, and many childhood
infections are commonly accompanied by skin changes.
Skin Disorders of Infancy
Throughout infancy, the skin is especially sensitive to
irritation from harsh chemicals, humidity, and heat.
Diaper Dermatitis.
Irritant diaper dermatitis, or
diaper
rash,
is a form of contact dermatitis caused by the inter-
action of several factors, including prolonged contact of
the skin with a mixture of urine and feces. The appear-
ance of diaper rash ranges from simple (i.e., widely dis-
tributed macules on the buttocks and anogenital areas)
to severe (i.e., beefy, red, excoriated skin surfaces in the
diaper area). Secondary infections with bacteria and
yeasts are common; discomfort may be marked because
of intense inflammation. Such conditions as contact
dermatitis, seborrheic dermatitis, candidiasis, and
atopic dermatitis should be considered when the erup-
tion is persistent and recalcitrant to simple therapeutic
measures.
Diaper dermatitis often responds to simple measures,
including frequent diaper changes with careful cleansing
of the irritated area to remove all waste products. Feces
in particular should be removed from the skin as soon as
possible after the diaper has been soiled. Because soap
and lipid solvents remove protective lipids from the stra-
tum corneum, using water or an alcohol-free baby wipe
is recommended. Exposing the irritated area to air is
helpful. It has been shown that application of a barrier
ointment after each diaper change is a valuable compo-
nent of therapy. Topical corticosteroid therapy is usually
effective, but should be used cautiously because infants
absorb proportionately greater quantities through their
skin than adults. Antifungal therapy should not be used
routinely, but can be helpful when
Candida
infection is
established or suspected. Antibacterial agents should not
be used because bacterial infections are rarely involved
in diaper dermatitis, and the normal microflora should
be preserved.
Intractable and severe cases of diaper dermatitis
should be seen by a health care provider for treatment
SUMMARY CONCEPTS
■■
Nevi or moles usually are benign neoplasms of
the skin. Because they may undergo cancerous
transformation, any mole that changes warrants
immediate medical attention.
■■
Repeated exposure to the UV rays of the sun has
been implicated as the principal cause of skin
cancer.
■■
The melanocytes, which protect against sunburn
through increased production of melanin, are
particularly vulnerable to the adverse effects
of unprotected exposure to ultraviolet light.
Malignant melanoma, which is a cancerous tumor
of melanocytes, is a rapidly progressive and
metastatic form of skin cancer.The most important
clinical sign is the change in size, shape, and color
of pigmented skin lesions, such as moles. As the
result of increased public awareness, melanomas
are now more likely to be diagnosed at an earlier
stage, when they can be cured surgically.
■■
Basal cell carcinoma, which is a neoplasm of the
nonkeratinizing cells of the basal layer of the
epidermis, is the most common skin cancer in
light-skinned people. It is slow-growing and rarely
metastasizes.
■■
Squamous cell tumors resemble the epidermal
cells of the stratum spinosum to varying degrees
and extend into the adjacent dermis. Squamous
cell carcinoma may remain confined to the
epidermis for a period of time, but at some
unpredictable time, it becomes invasive and
metastasizes to the regional lymph nodes. Chief
among the risk factors for tumor invasion and
metastasis are the size and location of the tumor.
