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Figure 18-42 Third-degree burn on a hand.
■ Symptoms. This burn is characteriz
ed by charred and
broken tissue layers. The affected individual can exhibit
signs and symptoms of shock.
■ Treatment. Third-degree burns often need tissue
grafting to heal. Scarring and deformity are common
with third-degree tissue damage.
The amount of body surface burned gener
ally correlates with the chance of survival for the
affected individual. Body surface may be determined
by applying the rule of nines (Figure 18-43). Burns
exceeding 9% of the body are serious and should be
treated in large medical centers with special burn
units. Generally speaking, body burns of 25% to 30%
of the body are extremely serious, and 60% body
burns are usually fatal.
Other factors affecting the chance of survival
include age, health, quality of care, and complications.
Those who are older and the very young do not survive
serious burns as well as other age groups.
Cold Injuries
■ Description. Cold thermal injury is usually not as
severe or life-threatening as heat or burn injuries. Hypo
thermia (hypo = low, therm = temperature) occurs when
the body’s core temperature falls below 95°F, which can
occur when the body is cold for a long period of time
or is exposed to extreme cold for even short periods of
time. Exposure to wind and water increases the chilling
effect and can lead to hypothermia in shorter amounts
of time.
■ Symptoms. Symptoms of hypothermia include
extreme shivering, mental confusion, blue or cyanotic
extremities, and weak pulse.
Figure 18-43 Rule of nines: used to calculate percentage of body surface burned.
438 Chapter 1 8
■ Treatment. Treatment includes removing wet cloth
ing and warming the body with warm blankets, warm
packs, or another person’s body. Warm liquids can be
given if the individual is conscious. The affected indi
vidual should be immediately transported to an emer
gency medical facility. Hypothermia can be fatal.
Frostbite
■ Description. Frostbite is the freezing of tissue, usu
ally on the face, fingers, toes, and ears, and might or
might not occur with hypothermia. Tissue affected by
severe frostbite can become necrotic and need surgical
debridement or amputation.
■ Symptoms. The tissue affected by frostbite usually
is painless and white in color. With warming, the skin
becomes painful and turns red.
■ Treatment. Treatment includes rapid warming in
warm (not hot) water baths, not rubbing the affected
tissue, and emergency treatment at a medical facility.
Electrical Injury
Electrical tissue injury is the result of contacting unpro
tected or inadequately insulated electrical wiring or
coming in contact with lightning. Whatever the cause
of injury, electrical tissue damage has a point of entry
and an exit point. The point of entry is the area coming
in contact with the electrical source and the exit point is
the grounded area. Electricity travels through the body
from point of entry to point of exit, causing burns and
often causing deep tissue injury.
A common cause of death related to electrical
injury is from respiratory and cardiac arrest. These con
ditions are caused by the physical jolt of electricity and
the disruption of the heart’s conduction system caused
by the electrical current as it passes through the body.
Radiation Injury
Radiation injury can be caused by ionizing radiation
such as X-rays and by sunlight. Of the two, sunlight
injury is the most common. Exposure to sunlight for
short amounts of time leads to skin redness, but pro
longed exposure can cause first- and second-degree
burns to the skin. Fair-skinned persons are the most
easily burned due to a lower number of pigment cells
in the skin. Tanning of the skin occurs as a protec
tive mechanism. Tanned skin returns to normal color
when pigmented keratocytes in the epidermis are
shed. Pigmented skin cells shed approximately every
30 days.
Radiation injury also can occur from exposure to
tanning beds, which tan skin in the same manner as
sun exposure. Tanning of the skin is a popular activity
because of the cosmetically pleasant color produced,
but the long-term effects of tanning are not so pleas
ant. Prolonged exposure to the sun or tanning beds
causes the skin to become prematurely dry, brittle, and
wrinkled and to lose elasticity. These effects cause the
skin to appear much older than its natural age. Another
unpleasant effect of the sun exposure is the develop
ment of skin cancers as discussed previously in this
chapter.
Pressure Injury
Pressure injury is caused when placing pressure against
tissue leads to a decrease in blood flow to this area. The
most common type of pressure injury is a decubitus
ulcer. Corns and calluses are also the result of pressure
injury.
Decubitus (Pressure) Ulcer
■ Description. Decubitus (dee-KYOU-bih-tus) ulcer is
a pressure injury commonly called a bedsore or pressure
sore (Figure 18-44). The term decubitus actually means
the act of lying down or the position of lying down.
■ Etiology. Decubitus ulcers commonly affect the
bony areas of the body such as the heels, sacrum,
elbows, and head of individuals who spend prolonged
amounts of time in bed. Increased pressure in these
areas slows blood flow, thus leading to tissue isch
emia and necrosis.
Figure 18-44 Decubitus ulcer on a buttocks.
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Integumentary System Diseases and Disorders 439
■ Prevention. Pressure sores can be avoided by frequent
turning and repositioning to decrease tissue pressure
and allow blood flow to the tissues. Massaging the
affected area also can improve circulation.
Corns and Calluses
■ Description. Corns and calluses are protective hyper
plasias of tissue as a result of pressure. The main differ
ence between a corn and a callus is the location. Corns
are commonly found on the feet and are due to ill-fitting
shoes. Corns are usually painful, and the affected indi
vidual might seek to have them surgically removed.
Calluses are found in the palms of the hands and
are related to pressure injury to the hands, generally
due to working with hand tools or performing labor.
Calluses are usually not painful and, in fact, protect the
hands from repeated abrasions and blisters.
Insect and Spider Bites and Stings
There are thousands of varieties of insects and spiders. Most
bites and stings are mild and cause only itching at the site,
but in a few people, these can bring about a serious reaction.
Most bites and stings can be treated with home remedies.
Insect Bites and Stings
■ Description. Insect bites and stings vary from
bloodsucking mosquitoes, ticks, flies, fleas, and
bedbugs to the stings of bees, wasps, hornets, yellow
jackets, and fire ants. Most of these bites and stings
feel unpleasant and might cause swelling and itch
ing at the site; however, insect bites also can transmit
diseases such as malaria, yellow fever, and the Zika
virus.
■ Symptoms. Signs and symptoms of insect bites or
stings often result from the injection of venom or poi
son into the skin. This venom incites an allergic reac
tion, the severity of which depends on the individual’s
sensitivity. Most symptoms are mild and disappear
within a few days. An allergic reaction might cause
intense itching, fever, and joint pain. A small percent of
people develop a severe reaction called anaphylaxis, as
discussed in Chapter 5, “Immune System Diseases and
Disorders.”
■ Treatment. Treatment for mild reactions includes
moving to an area to avoid more insects; if a stinger
is involved, scraping or brushing it off with a knife or
credit card; washing the affected area with soap and
water; applying ice; applying hydrocortisone cream;
and taking an antihistamine such as diphenhydramine
(Benadryl®). Pain can usually be controlled by a mild
analgesic such as Tylenol.
If a severe reaction occurs with symptoms such as diffi
culty breathing, swelling of the face or lips, hives, tachycar
dia, nausea, and vomiting, call 911 for immediate assistance.
Healthy Highlight
The Lone Star Tick
and Red Meat
Food Allergies
R
esearchers have linked some red meat allergies to tick bites. Ticks are most com
mon in the southern and central United States. One tick, the Amblyomma america-
num, also called the Lone Star tick, releases alpha-gal into the victim when it bites, and
it is this carbohydrate that triggers the immune reaction. The carbohydrate is found
in many mammals, such as cows, pigs, or sheep, but not usually in humans. Alpha-gal
causes a reaction if it enters the blood system of susceptible individuals through the
tick bite, but does not seem to affect anyone when it is just consumed in meat. Once the
body has developed antibodies to the alpha-gal, after being bitten by the tick, then the
antibodies will react when exposed to red meat containing alpha-gal. Reactions usually
produce such symptoms as a rash, runny nose, itching, nausea or vomiting, headache,
asthma, or anaphylactic shock. The best way to stay healthy and prevent this syndrome
is to avoid tick bites. The only treatment is to avoid eating foods that cause the allergic
reactions. Researchers are continuing to study the effects of the tick bites and the sub
sequent allergic reactions to red meat.
Source: Mayo Clinic (2020)
440 Chapter 18
Other emergency responses include laying the vic
tim down on his or her back with feet higher than head,
loosening tight clothing, covering with a blanket, and
checking for special medications the individual might
have for allergic reaction, such as an EpiPen. If vom
iting occurs, turn the individual on his or her side to
prevent aspiration. If breathing stops, begin cardiopul
monary resuscitation (CPR).
■ Prevention. To prevent bites and stings, use insect
repellent, wear protective clothing, and watch for and
avoid insect nests. If you have allergies to insects, always
carry an emergency epinephrine kit.
Spider Bites
More than 20,000 species of spiders exist in the Americas,
yet only 60 are capable of biting humans and, of these,
only a few have a serious bite. Most spiders are not poi
sonous and are helpful to have around because they eat
insects that can be annoying. However, two commonly
poisonous spiders are the black widow and brown recluse.
Black Widow Bite
■ Description. The black widow is by far the most com
monly known poisonous spider due to its famous red
markings in the shape of an hourglass (Figure 18-45).
The name comes from a mistaken belief that the female
spider kills the male after mating. They are found mostly
in the southern United States but appear in all states except
Alaska. They try to avoid humans and tend to live in
garages and attics. Only the female bites, and this happens
usually when she is disturbed or trying to protect her eggs.
■ Etiology. The venom of the black widow is a protein
that affects the victim’s nervous system. Even though
this venom is one of the most potent produced by spi
ders, it causes severe response in only a few individuals.
■ Symptoms. The first symptom is acute pain at the
site. Other, more severe, symptoms include abdominal
pain that mimics appendicitis, muscle cramps, nausea,
fainting, dizziness, and chest pain.
The severity of the reaction to the bite depends on
the age of the victim: the elderly and children are the
most seriously affected. The bite is seldom fatal.
■ Treatment. Treatment includes cold compresses and
pain relievers. Children, pregnant women, hypertensive
individuals, and the elderly, if bitten, should be taken to
the hospital for treatment.
■ Prevention. Prevention of bites includes taking care
when reaching into dark areas where spiders might be liv
ing and eradicating spiders using professional pest services.
Brown Recluse Bite
■ Description. The bite of the brown recluse spider can
be very dangerous. Brown recluse spiders, also called
fiddleback spider, violin spider, or brown fiddler, are
native to the midwestern and southeastern United States
(Figure 18-46). They live up to their name in that they have
a distinctive violin shape on their backs and tend to hide
Figure 18-45 Black widow spider. Figure 18-46 Brown recluse spider.
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Integumentary System Diseases and Disorders 441
in dark, warm, dry areas such as attics, closets, porches,
barns, and woodpiles and, in some instances, inside shoes.
They are not aggressive and bite only when threatened and
actually pressed against an individual’s skin.
■ Etiology. The bite venom is a collection of enzymes
that is extremely poisonous to a level that some say is
more potent than a rattlesnake’s. Even so, most bite sites
become firm and heal within a few days with little scar
ring. On occasion, however, the reaction in the bite area
will be more severe, with redness, blistering, and blue
discoloration. The venom can cause destruction to tis
sues, often leading to necrosis of skin, fat, and blood
vessels in areas immediately surrounding the bite site
(Figure 18-47). Bites are rarely fatal, but deaths have
been reported in children younger than 7 years of age.
■ Symptoms. Symptoms of a brown recluse spider bite
include severe pain, severe itching, fever, nausea, and
muscle pain.
■ Diagnosis. Diagnosis is based on a careful history
and examination of the bite site, but no specific lab
studies can confirm a brown recluse bite. Diagnosis
can be confirmed only if the spider is available for
identification.
■ Treatment. First aid consists of the application of an
ice pack, administration of analgesic medications, and
acquisition of prompt medical care. Further treatment
includes pain medication, antihistamines, and antibiot
ics if infection occurs. No antivenin medication is avail
able. A follow-up visit to the doctor might be necessary
to monitor the wound, debride necrotic tissue if needed,
and treat any secondary infection.
If possible, the spider should be caught in a clear,
tightly closed container for future identification. It is
important to seek medical treatment if a brown recluse
bite is suspected because, in rare cases, necrosis can
spread quickly, particularly when the venom reaches
a blood vessel. When venom travels along a vein or
artery, the resulting necrosis of tissue can be as large as
several inches and might require extensive excising of
tissue around the wound.
■ Prevention. Prevention of brown recluse spider bites
includes activities to eliminate the spider by thorough
Courtesy of Melody and Anna Troutman
Figure 18-47 Stages of a brown recluse spider bite. (A) Wound — a few hours after bite. (B) Wound—1 day after bite.
(C) Wound—2 days after the bite. (D) Wound — after debridement of necrotic tissue.
442 Chapter 18
house cleaning, installing tight-fitting windows and
doors, and professional pest elimination services.
Rare Diseases
Elephantiasis
Elephantiasis is characterized by hypertrophy of the
skin and subcutaneous tissue, giving it an elephant-like
appearance. Inflammation of the lymphatic system also
leads to fluid accumulation in the legs, causing them
to become enlarged. Elephantiasis is caused by a para
sitic worm that enters the lymphatic system and causes
obstruction of drainage and accumulation of fluids.
This disease is most commonly seen in tropical areas,
such as central Africa, and is spread by mosquitoes and
bloodsucking flies.
Effects of Aging on the System
function as well, further contributing to the dry skin
problem. The youthful elasticity of the skin is lost, caus
ing wrinkles and an aged appearance. If the individual
has spent a great deal of time in the sun over the years,
these problems will be exaggerated. The nails become
thicker and might be difficult to trim. The hair becomes
thinner and brittle. There might be extensive hair loss
and graying.
Skin lesions are common in older people. Ker
atoses and skin cancers are the most common prob
lems, especially in individuals who have been exposed
to sunlight for many years without using protection
(Figure 18-48). Seborrheic dermatitis, rosacea, and
psoriasis are frequently seen disorders. Older adults
with chronic disorders such as diabetes or peripheral
vascular diseases are particularly prone to develop skin
problems, especially pressure injuries. Older adults are
also more likely to experience burn or cold injuries
because they have decreased touch sensation.
Numerous changes develop in the integumentary sys
tem during the aging process. The epidermal layer
becomes thinner and retains less water, which accounts
for the easy tearing and dryness of the skin common in
older adults.
Xerosis (zee-ROE-sis; dry skin) is a major prob
lem in older adults, who might have flaky, scaly skin
and pruritus. The sweat and sebaceous glands do not
Figure 18-48 Senile keratosis.
Summary
T
he skin is important in protecting the body from pathogens; in providing sensations of touch, heat, and cold;
and in regulating body temperature. There are numerous skin conditions, some of which are manifestations of
other body system diseases. Skin problems are very traumatic to the individual because they affect appearance and
can cause extreme discomfort. Skin diseases range from mild to severe and from acute to chronic. Treatment for
many of the skin conditions is symptomatic. Changes in the integumentary system in the older adult cause dry skin;
thick, brittle nails; and gray, thinning hair. Older people are at increased risk for secondary skin disorders related
to other system diseases.
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Integumentary System Diseases and Disorders 443
Review Questions
Short Answer
1. What is the main function of the integumentary system?
2. What are the most common symptoms of integumentary system disorders?
3. Which diagnostic tests are used to diagnose integumentary system disorders?
Matching
4. Match the skin condition in the left column with its description in the right column.
________ Herpes a. A form of cellulitis commonly involving the face
________ Verruca b. A chronic autoimmune disorder characterized by hardening and
thickening of the skin and connective tissue
________ Folliculitis c. A condition caused by a tiny mite that burrows into the skin
________ Erysipelas d. An inflammation and infection of the hair follicle
________ Tinea e. A viral disease characterized by inflammation and fluid-filled
blisters
________ Scabies f. A chronic skin condition characterized by red, raised lesions
with distinct borders and silvery scales
________ Eczema g. A condition caused by papillomavirus that affects the keratin
cells, causing hypertrophy
________ Psoriasis h. An inflammation of the skin also known as atopic dermatitis
________ Scleroderma i. A group of contagious fungal diseases of the skin
True or False
5. T F
6. T F
7. T F
8. T F
9. T F
10. T F
11. T F
12. T F
Genital warts are a sexually transmitted disease.
Carbuncles are most commonly caused by Staphylococcus bacteria.
Pediculosis is an infestation of lice.
Tinea capitis is also known as jock itch because it is located in the groin area.
Comedones are plugged skin pores found in cases of acne.
A port wine stain is a type of erythema found on the neck or trunk of the body.
An avulsion is a traumatic crushing injury, often caused by heavy objects dropped on parts of the
body such as the fingers.
Skin cancer is the most common type of cancer diagnosed in individuals.
444 Chapter 18
13. T F Radiation injury can be caused by ionizing radiation such as X-rays and by sunlight.
14. T F In burn injuries, the amount of body surface burned generally correlates with the chance of sur
vival of the affected individual.
15. T F Third-degree burns, also called partial-thickness burns, involve the epidermis and dermis.
16. T F Cold thermal injury is usually more severe or life-threatening than heat or burn injuries.
17. T F In the aging process, the elasticity of the skin is lost, causing wrinkles and an aged appearance only
if the individual has had constant exposure to sunlight over the years.
Case Studies
■ Jenny Johnson is a 21-year-old college student who has vitiligo. She has some patchy areas on her legs and
just a few on her arms. She visits the health clinic on campus where you work to talk about treatment for the
disorder. What options are available for her? Is vitiligo detrimental to her overall health? What can you tell her
about the progression of the problem? Where might she find out more information about her disorder?
■ Mrs. Moore is a 54-year-old school teacher who has been diagnosed with psoriasis. At the present time, she
has a few patches on her arms and legs, but not an extensive amount. She asks you to give her more information
about the disorder. She wants to know whether it will get worse, if it will eventually heal, what she can do to
relieve the symptoms, whether it is contagious, whether it is genetic, and what might cause it to get worse. How
would you answer her questions? How much information should you give Mrs. Moore? Where might you refer
her for more information? What is her long-term prognosis?
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Unit
Genetic and
Developmental,
Childhood, and Mental
Health Diseases and
Disorders
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