This section will provide a general overview of diseases, disorders, and injuries of the integumentary system.^[1]

Acne

Acne (AK-nē) is a skin condition characterized by inflamed or infected sebaceous glands in the skin, particularly on the face and back. Sebaceous glands (oil glands) produce sebum (an oily substance). An accumulation of sebum and keratin blocks hair follicles, resulting in acne. Acne is common during puberty due to associated hormonal changes. Severe acne can cause scarring.^[2] See Figure 3.7^[3] for an image of acne.

Benign Growths

Benign (bē-NĪN) growths or tumors are not cancerous and do not spread to other parts of the body like cancer does, but they may require removal. Examples of benign tumors in the integumentary system are dermatofibroma (dĕr-mă-tō-fī-BRŌ-mă), a firm, nodular growth on the skin, and lipoma (lī-PŌ-mă), a fatty tissue tumor.

Burns

A burn (bûrn) results when the skin is damaged by intense heat, radiation, electricity, or chemicals. Burns can lead to a massive fluid loss due to loss of protection against dehydration by the skin. Burned skin is also extremely susceptible to infection due to the loss of protection against pathogens by the skin.

Burns were traditionally classified by their degree of severity as first-degree, second-degree, third-degree, and fourth-degree burns. This historic classification of burns has been replaced by a system reflecting the need for surgical intervention. They are referred to as superficial, superficial partial-thickness, deep partial-thickness, and full-thickness burns:

• A first-degree burn, now referred to as a superficial burn, only affects the epidermis. Although the skin may be painful and swollen, these burns typically heal on their own within a few days. Mild sunburn fits into the category of a first-degree burn.
• A second-degree burn, now referred to as a partial thickness burn, affects both the epidermis and a portion of the dermis. These burns result in swelling and a painful blistering of the skin. It is important to keep the burn site clean to prevent infection. With good care, a second-degree burn will heal within several weeks.
• A third-degree burn, now referred to as a full-thickness burn, extends fully into the epidermis and dermis, destroying the tissue and affecting the nerve endings and sensory function. These are serious burns that require immediate medical attention.
• A fourth-degree burn, now referred to as a deep full-thickness burn, is even more severe, affecting the underlying muscle and bone.

Full-thickness burns require debridement (di-BRĒD-mĕnt), surgical removal of dead tissue, followed by grafting skin from an unaffected part of the body or from skin grown in tissue culture.^[4] See Figure 3.8^[5] for an image of a patient recovering from a second-degree burn on the hand.

Severe burns are quickly measured in emergency departments using a tool called the “Rule of Nines,” which associates specific anatomical locations with a percentage of the body that is a factor of nine. Rapid estimate of the burned surface area is used to estimate the amount of intravenous fluids needed to replace fluid loss.^[6] See Figure 3.9^[7] for an illustration of the Rule of Nines. Using the Rule of Nines, the head is calculated as 9%, the upper limbs are 9% (4.5% on each side), the lower limbs are 18% (9% on each side), and the trunk is 36% (18% on each side), and the perineum/genitalia is 1%.

Eczema

Eczema (eg-ZĒ-mă) is an allergic, inflammatory condition that manifests as dry, itchy patches of skin that resemble a red, flaky rash. It can occur in individuals of all ages. See an image of eczema in Figure 3.10.^[8] Eczema may be accompanied by swelling of the skin, flaking, and, in severe cases, bleeding. Symptoms are usually managed with moisturizers, corticosteroid creams, and immunosuppressant medication.

Edema

Edema (ĕ-DĒ-mă) is caused by fluid accumulation within the tissues often caused by underlying cardiovascular or renal disease.  Lymphedema (lim-fĕ-DĒ-mă) is the medical term for a type of swelling that occurs when lymphatic fluid builds up in the body’s soft tissues due to damage to the lymph system. It often occurs unilaterally in the arms or legs after surgery has been performed that injured the regional lymph nodes. See Figure 3.11^[9] for an image of lymphedema. Causes of lymphedema include infection, cancer, scar tissue from radiation therapy, surgical removal of lymph nodes, or inherited conditions. There is no cure for lymphedema, but elevation of the affected extremity is vital. Compression devices and massage can help to manage the symptoms.

Infections

An infection (in-FEK-shŏn) is caused by the invasion and multiplication of microorganisms in the body, such as bacteria (bak-TĒR-ē-a), viruses, fungi, and parasites. Microorganisms that cause infection are referred to as pathogens (path-Ŏ-jĕns).

Bacterial Infections

Bacterial skin infections are commonly caused by Staphylococcus (staf-ĭ-lō-KOK-ŭs) or Streptococcus (strep-tŏ-KOK-ŭs) bacteria. Methicillin-resistant Staphylococcus aureus (mĕth-ĭ-SĬL-ĭn rĕ-zĭs-tănt STĂF-ə-lō-KŌK-ŭs OWR-ē-ŭs) (MRSA) is a staph infection that is resistant to common antibiotics. There are two types of MRSA, referred to as community-acquired and hospital-acquired. Hospital-acquired MRSA (HA-MRSA) is diagnosed in people who acquired the infection while in the hospital or other health care setting and undergoing treatment for another medical condition. People in the hospital are at higher risk of becoming infected with MRSA because they often have breaks in their skin due to surgical wounds or intravenous lines (IVs) that allow bacteria to enter. Community-acquired MRSA (CA-MRSA) is a MRSA infection that is diagnosed in individuals outside of a hospital setting. It tends to occur in individuals who have had close skin-to-skin contact with another person with CA-MRSA. Different antibiotics are used to effectively treat HA-MRSA and CA-MRSA.

Bacterial infections often cause the development of pus. Pus (PŬS) is a thick, opaque yellow or green fluid produced in infected tissue, consisting of dead white blood cells, bacteria, and tissue debris. A boil (BOIL) is a painful, pus-filled bump that forms under the skin, often caused by an infected hair follicle. An abscess (ĂB-sĕs) is a swollen area within body tissue, containing an accumulation of pus.

Impetigo (ĭm-pĕ-TĪ-gō) is a contagious bacterial skin infection forming pustules and yellow, crusty sores, typically found in children between the ages of two and six. A pustule (PŬS-tūl) is a small blister or pimple on the skin that contains pus. See Figure 3.12^[10] for an image of impetigo. Impetigo often starts when bacteria enter a break in the skin, such as a cut, scratch, or insect bite. Symptoms start with red or pimple-like sores surrounded by red skin. The sores fill with pus and then break open after a few days and form a thick crust. They are often itchy but scratching them can spread the sores. Impetigo can spread by contact with sores or nasal discharge from an infected person and is treated with antibiotics.

Cellulitis (sĕl-yū-LĪ-tĭs) is a bacterial infection of the skin and subcutaneous tissue, characterized by redness, pain, heat, and swelling. Untreated cellulitis can become severe and spread throughout the body.

Viral Infections

Viruses are contagious and are easily spread among individuals. They can cause several different types of skin infections. A virus (VĪ-rŭs) is a microorganism that spreads infection by invading the body’s cells and replicating. For example, a wart (WART), also referred to as a verruca (vĕr-ROO-kă), is a small benign growth on the skin caused by a virus.

Genital warts are caused by human papillomavirus (hyū-măn pap-ĭ-lō-mă-VĪ-rŭs) (HPV), the most common sexually transmitted infection in the United States. Genital warts appear as a small bump or group of bumps in the genital or anal area. They can be small or large, raised or flat, or shaped like a cauliflower. In some individuals, HPV can progress to cancer. HPV can cause cervical, throat, and other cancers. HPV vaccines help prevent some of the health effects HPV causes.^[11]

Shingles (SHING-gĭlz) is a viral disease that causes painful rashes on the skin. Shingles is caused by the varicella-zoster virus, the same virus responsible for chickenpox. A vaccine is available to prevent shingles and is recommended for adults over age 50 or for individuals with compromised immune systems.

Fungal and Yeast Infections

Tinea (TIN-ē-ă) is the name of a group of skin infections caused by a fungus. These infections are usually not serious, but they can be uncomfortable because of the symptoms of itching and burning. They can be transmitted by touching other people’s infected areas, damp surfaces such as shower floors, or even from pets.^[12]

Tinea infections are commonly referred to as ringworm, athlete’s foot, and jock itch. Ringworm or tinea corporis (TĪ-nē-ă KŌR-pŏ-rĭs) is a type of rash that forms on the body that typically looks like a red ring with a clear center, although a worm doesn’t cause it. Scalp ringworm or tinea capitis (TĪ-nē-ă KĂP-ĭ-tĭs) causes itchy, red patches on the head that can leave bald spots. Athlete’s foot or tinea pedis (TĪ-nē-ă PĔD-ĭs) causes itching, burning, and cracked skin between the toes. Jock itch or tinea cruris (TĪ-nē-ă KRŌŏ-rĭs) causes an itchy, burning rash in the groin area. Fungal infections are often treated successfully with over-the-counter creams and powders. See Figure 3.13^[13] for an image of a tinea in a patient’s groin.^[14]

Fungal infections of nails are referred to as onychomycosis (ŏn-ī-kō-mī-KŌ-sĭs).

Yeast infections (YĒST ĭn-FĕK-shŭns) are commonly caused by Candida, a type of fungus. Candida normally lives on people’s skin and inside their body without causing problems. However, Candida can cause yeast infections if it grows out of control. It can be caused by antibiotics that kill the normal flora on the skin or by diseases that reduce an individual’s immune response.

Lice

Head lice are tiny insects that live on a person’s head. Pediculosis (pĕd-ĭ-kū-LŌ-sĭs) refers to a lice infection/infestation. Adult lice are about the size of a sesame seed, but the eggs, called nits, are smaller and can appear like a dandruff flake. See Figure 3.14^[15] for an image of very small white nits in a person’s hair.

Children ages 3-11 often get head lice at school or daycare because they have head-to-head contact while playing together. Lice move by crawling and spread by close person-to-person contact. Rarely, they can spread by sharing personal belongings such as hats or hairbrushes. Contrary to popular belief, personal hygiene and cleanliness have nothing to do with getting head lice. Symptoms of head lice include the following:

• Tickling feeling in the hair
• Pruritus (prū-RĪ-tŭs) or severe itching caused by an allergic reaction to the bites
• Sores from scratching, which can become infected with bacteria
• Trouble sleeping due to head lice being most active in the dark

Head lice are diagnosed after the observation of one live louse on a person’s head. Because they are very small and move quickly, a magnifying lens and a fine-toothed comb may be needed to find lice or nits. Treatments for head lice include over-the-counter and prescription shampoos, creams, and lotions such as permethrin lotion.^[16]

Scabies

Scabies (SKĀ-bēz) is an infection caused by tiny mites that burrow into the skin, leading to intense pruritis (itching).

Injuries

There are many types of injuries that can occur to the skin:

• An abrasion (ă-BRĀ-zhŏn) is an area of skin damaged by scraping or wearing away. See Figure 3.15^[17] for an image of an abrasion.
• A blister (BLIS-tĕr) is a raised portion of the skin in which the epidermis becomes lifted up off the dermis and is filled with fluid. Blisters are typically caused by friction, burns, or other damage.
• A bulla (BOO-la) is a large blister.
• A bruise (BRŪZ), also referred to as a contusion (kŏn-TOO-zhŏn), is an injury appearing as an area of discolored skin on the body, caused by a blow or impact rupturing underlying blood vessels.
• A laceration (las-ĕ-RĀ-shŏn) is a deep cut or tear in skin and/or tissue.
• A skin ulcer (UL-sĕr) is an open sore on the body that is often slow to heal and prone to infection. There are many potential causes of ulcers, such as pressure injures and lack of blood flow from diabetes.
• Calluses (KĂL-ū-ses) are thick, hardened layers of skin that develop when the skin tries to protect itself against friction or pressure. For example, calluses can often form on fingers if they are subjected to constant mechanical stress, such as long periods of writing with a pencil or playing string instruments. A corn is a specialized form of callus that develops on the tops and sides of toes and can be painful.

Pressure Injuries

Pressure injuries, formerly referred to as pressure ulcers or bedsores, form when a patient’s skin and soft tissue press against a hard surface for a prolonged period of time. The pressure against a hard surface reduces blood supply to that area, causing damage to the skin tissue and possible ulcers. Patients are at high risk of developing a pressure injury if they spend a lot of time in one position without moving or have decreased sensation, poor nutrition, or bladder or bowel leakage.^[18] See Figure 3.16^[19] for an image of a pressure ulcer injury on the back of a patient who is bed-bound due to chronic illness. Pressure injuries are most common in patients who have debilitating conditions that cause them to be immobile. Nurses and other health care professionals reposition immobile patients every few hours to prevent the formation of pressure injuries.

Psoriasis

Psoriasis (sō-RĪ-ə-sĭs) is a skin condition marked by red, itchy, scaly patches found on the elbows, knees, scalp, low back, face, feet, fingernails, toenails, and even the mouth. Treatments may include creams, ointments, ultraviolet light therapy, and medication.^[20]

Rashes

A rash is an area of redness and small spots appearing on the skin due to allergy or illness. There are different types of rashes that may occur, each with different appearances and causes. Terms used to describe rashes include the following:

• Macule (MAK-ūl): A flat, discolored spot on the skin.
• Papule (PAP-ūl): A small, raised, solid bump.
• Vesicle (VES-ĭ-kĭl): A small, fluid-filled sac or blister within or under the epidermis.
• Urticaria (ur-tĭ-KĀR-ē-ă): Raised, itchy welts on the skin, also known as hives. A wheal refers to an individual hive.

Dermatitis (dûr-mă-TĪ-tĭs) is inflammation of the skin that can cause a rash. A common type of dermatitis is called contact dermatitis, caused by contact with a substance that causes an allergic reaction. For example, allergic skin reactions caused by latex allergy or poison ivy are examples of contact dermatitis. Dermatoconiosis (dûr-mă-tō-kō-nē-Ō-sĭs) is a type of dermatitis caused by dust contacting the skin.

Systemic lupus erythematosus (sis-TĔM-ik LOO-pŭs ĕr-i-thē-mă-TO-sŭs) (SLE), commonly referred to as lupus (LOO-pŭs), is an autoimmune disease in which the immune system recognizes its own cell antigens as being “non-self” and mounts an immune response against them. As a result, skin, body tissues, and vital organs become chronically inflamed and damaged. A common sign of lupus is a facial rash that resembles the wings of a butterfly unfolding across both cheeks. See Figure 3.17^[21] for an image of a butterfly rash associated with lupus.

Petechiae (pĕ-TĒK-ē-ī) are tiny red dots that can be mistaken as a rash but are actually caused by bleeding under the skin. Large petechiae are called purpura (PUR-pyŏŏ-ră). An easy method used to assess for petechiae is to apply pressure to the rash with a gloved finger. A rash will blanch (i.e., whiten with pressure), but petechiae and purpura do not blanch. See Figure 3.18^[22] for an image of petechiae and purpura. New onset of petechiae should be immediately reported to a health care provider because it can indicate a serious underlying medical condition.^[23]

Scars and Keloids

A scar (skăr) is a mark left on the skin where an injury, wound, or burn did not completely heal, resulting in collagen-rich fibrous connective tissue formation. Modern cosmetic procedures, such as dermabrasion, laser treatments, and filler injections are used to treat severe scarring. These procedures reorganize the structure of the epidermis and the underlying collagen tissue to make it look more natural.

In some individuals, an overproduction of scar tissue occurs when the process of collagen formation does not stop after the wound is healed. This overproduction causes a raised scar called a keloid (KĒ-loyd).^[24] Keloids are more common in patients with darker skin color. See Figure 3.19^[25] for an image of a keloid that has developed from a scar on a patient’s chest wall.

Skin Cancer

Skin cancer is common, with one in five Americans experiencing some type of skin cancer in their lifetime. Basal cell carcinoma (BĀ-săl sel kar-sĭn-Ō-ma) is the most common of all cancers that occur in the United States and is frequently found on areas most susceptible to long-term sun exposure such as the head, neck, arms, and back. Basal cell carcinomas start in the epidermis and become an uneven patch, bump, growth, or scar on the skin surface. Treatment options include surgery, cryosurgery, and topical ointments.^[26]

Squamous cell carcinoma (SKWĀ-mŭs sel kar-sĭn-Ō-mă) presents as lesions commonly found on the scalp, ears, and hands. If not removed, squamous cell carcinomas can metastasize (mĕ-TĂS-tă-sīz) to other parts of the body. Surgery and radiation are used to cure squamous cell carcinoma. See Figure 3.20^[27] for an image of squamous cell carcinoma.^[28]

Melanoma (mel-ă-NŌ-mă) is skin cancer caused by the uncontrolled growth of melanocytes, the pigment-producing cells in the epidermis. Melanoma commonly develops from an existing mole that becomes abnormal. A mole (MŌL) is a small, dark, benign skin growth. See Figure 3.21^[29] for an image of a melanoma.

Individuals are encouraged to evaluate moles with an unusual appearance using the “ABCDE” rule that describes the features of early melanoma. These are the features:

• Asymmetry: The shape of one half does not match the other half.
• Border: The border is irregular, meaning the edges are ragged, notched, or blurred. The pigment may spread into the surrounding skin.
• Color: There is uneven color with different shades of black, brown, and tan. Areas of white, gray, red, pink, or blue may also be seen.
• Diameter: There is an increased change in the size of the mole. Most melanomas are larger than six millimeters wide (about 1/4 inch).
• Evolving: The mole has changed over the past few weeks or months.

Melanoma is the most fatal of all skin cancers because it is highly metastatic and can be difficult to detect before it has spread to other organs. Common treatments include Moh’s surgery and immunotherapy.^[30] During Mohs surgery (MŌZ SŬR-jĕr-ē), the surgeon removes thin layers of skin one layer at a time and examines each layer under a microscope to determine if any cancer remains. This procedure continues until only cancer-free tissue remains.^[31]

Skin Color Changes

Changes in the appearance of the color of an individual’s skin can be a symptom of many types of disorders:

• Redness in the skin caused by capillary dilation is referred to as erythema (ĕr-ĭ-THĒ-mă).
• A drop in oxygenation can cause the skin to develop pallor (PĂL-or), the medical term for paleness. Severe or prolonged reduction in oxygen levels cause the skin to appear blue, referred to as cyanosis (sī-ă-NŌ-sĭs). See Figure 3.22^[33] for an image of cyanosis in fingertips.
• Death of cells causes them to appear black, referred to as necrosis (nĕ-KRŌ-sĭs). See Figure 3.23^[34] for an image of necrosis spreading after an amputation.
• A yellow discoloration of the skin due to the accumulation of bilirubin is referred to as jaundice (JON-dĭs). Jaundice is discussed in more detail below the images.

Jaundice causes skin and sclera (whites of the eyes) to turn yellow, also referred to as xanthoderma. See Figure 3.24^[35] for an image of a patient with jaundice visible in the sclera and the skin. Jaundice is caused by too much bilirubin in the body. Bilirubin is a yellow chemical in hemoglobin, the substance that carries oxygen in red blood cells. As red blood cells break down, the old ones are processed by the liver. If the liver can’t keep up due to large amounts of red blood cell breakdown or liver damage, bilirubin builds up and causes the skin and sclera to appear yellow. New onset of jaundice should always be reported to the health care provider. Jaundice can happen at any age for many reasons, such as liver disease, blood disease, infections, or side effects of some medications. Jaundice also occurs in newborns due to the immaturity of their livers, but it quickly resolves on its own or with phototherapy treatment.^[36]

Albinism (AL-bĭ-nizm) is a genetic disorder that completely or partially affects the coloring of an individual’s skin, hair, and eyes. This disorder is primarily due to the inability of melanocytes to produce melanin. Individuals with albinism tend to appear white or very pale due to the lack of melanin in their skin and hair. Recall that melanin helps protect the skin from the harmful effects of UV radiation. Individuals with albinism require additional protection from UV radiation because they are more prone to sunburns and skin cancer. They also tend to be more sensitive to light and have vision problems due to the lack of pigmentation on the retinal wall.

In vitiligo (vĭt-ĭ-LĪ-gō), the melanocytes in certain areas of an individual’s body lose their ability to produce melanin, possibly due to an autoimmune reaction. This causes a loss of color in patches, as shown in Figure 3.25.^[37] The condition is especially noticeable in individuals with darker skin. 

Other Skin Conditions

Other skin conditions include the following:

• A birthmark (BURTH-mark) is a benign irregularity on the skin which is present at birth or appears shortly after birth.
• A cyst (sist) is a closed sac containing fluid, air, or other substances.
• Gangrene (GANG-grēn) is the death and decomposition of tissue, resulting from either infection or loss of blood supply.
• A lesion (lĒ-zhŏn) is an area of tissue that has suffered damage through injury or disease, such as a wound, ulcer, abscess, or tumor.
• Leukoplakia (loo-kō-PLĀ-kē-ă) refers to white, thickened patches on mucous membrane tissue of the tongue or cheek that cannot be scraped off. Leukoplakia is associated with chronic irritation, such as from tobacco use, including smoking and chewing.
• A nevus (NĒ-vŭs) is a pigmented skin blemish, commonly referred to as a “mole.”
• A nodule (NOJ-ool) is an abnormal growth of cells in the body that causes a lump and is distinct from its surroundings.
• Pruritus (proo-RĪT-ŭs) refers to severe itching. Pruritis can be caused by many types of disorders, such as contact dermatitis, insect bites, and viruses.
• Rosacea (rō-ZĀ-shē-ă) is a chronic skin disorder characterized by redness and pimples on the nose and cheeks.
• Striae (STRĪ-ē), commonly referred to as “stretch marks,” are caused by pressure associated with rapid growth, such as during puberty and pregnancy. They commonly occur over the hips and abdomen. A stretch mark results when the dermis is stretched beyond its limits of elasticity to accommodate the rapid growth. They initially have a reddish hue but lighten over time. Other than for cosmetic reasons, treatment of stretch marks is not required.
• Telangiectasia (tĕl-an-jē-ĕk-TĀ-zē-ă), commonly referred to as “spider veins,” refers to small, dilated blood vessels near the surface of the skin.
• Xeroderma (zē-rō-DUR-mă) refers to abnormally dry skin.