Skin Pigmentation Disorders

Definition

Skin pigmentation disorders are conditions that cause the skin to appear lighter or darker than normal, or blotchy and discolored.

Description

People of all races have skin pigmentation disorders. Some disorders, like albinism (which affects one out of every 17,000 people) are rare. Others, such as age spots, are very common.

Skin pigmentation disorders occur because the body produces either too much or too little melanin, a pigment that creates hair, skin, and eye color. Melanin protects the body by absorbing ultraviolet light.

In hypopigmentation means the body does not produces enough melanin. Albinism, for example, is an inherited condition that causes a lack of pigment. So people with albinism typically have light skin, white or pale yellow hair, and light blue or gray eyes. Another condition called vitilgo, creates smooth, depigmented white spots on the skin. Vitilgo affects nearly 2% of the population, but it strikes people between 10 and 30 years old more often, and is more evident in people with darker skin.

In hyperpigmentation, the body produces too much melanin, causing skin to become darker than usual. Lichen simplex chronicus is a skin disorder with severe itching that causes thick, dark patches of skin to develop. Lamellar ichthyosis (fish scale disease) is an inherited disease that also is characterized by darkened, scaly, dry patches of skin.

Hyperpigmentation also occurs in melasma, a dark mask-like discoloration that covers the cheeks and bridge of the nose. Melasma can occur during the end of pregnancy. People with the autoimmune disease (when immune cells, which attack invaders, become abnormally programed to kill self cells inside the body) systemic lupus also may develop a similar butterfly-shaped mask on their faces. In addition, many people have moles, freckles, age spots, and birthmarks, ranging from red or brown to bluish, black, covering various parts of their bodies.

Causes and symptoms

Scientists are still studying the reasons why skin pigmentation disorders occur. In some cases there are tangible causes, such as sun exposure, drug reactions or genetic inheritance. In other cases, it is not as clear.

Albinism is an inherited recessive trait. Albinism has many different forms, but most people who have this condition have pale skin, hair, and eyes. Melanin also creates eye color, and serves as a filter that prevents too much light from entering the eye. Since they lack melanin in their eyes, many people with albinism also have visual impairment. With little skin pigmentation, they also sunburn easily and are more prone to skin cancer.

The hypopigmentation spots associated with vitilgo sometimes form where a person has been cut or injured. Research has shown that the light patches associated with vitilgo do not contain melanocytes, the type of skin cells that create melanin. Some scientists believe vitilgo may be caused by an autoimmune disorder. It also has been linked to other conditions such as hyperthyroidism (too much thyroid hormone) and Addison's Disease, which affects the adrenal gland.

Hyperpigmentation can be caused by many factors, from too much sunbathing to drug reactions or poor nutrition. Wounds and scars also can develop darker patches of skin. A psychological syndrome gives people with lichen simplex chronicus to develop a compulsive need to scratch, which causes dark, leathery skin to form. This can lead to permanent scarring and infection if untreated. Scientists believe lamellar ichthyosis is caused by genetics.

The mask caused by melasma may be related to pregnancy hormones, and usually disappears after a woman gives birth. Birthmarks, moles, and aging spots usually are harmless. Some moles, however, can change in size, color, texture, or start bleeding, which could indicate possible skin cancer.

Diagnosis

Diagnostic tests vary for different types of skin pigmentation disorders. Physicians usually can diagnose albinism by looking carefully at a person's hair, skin, and eyes. They may order blood tests and eye exams as well. A visual exam also is enough to diagnose vitilgo.

For most hyperpigmentation disorders, doctors can make a diagnosis by looking at a person's appearance. To detect conditions like lichen simplex chronicus or lamellar ichthyosis, or skin cancer, they may also do a biopsy to remove some of the affected skin for further study under a microscope. Some physicians also use a wood's lamp, or black light test, to diagnose skin conditions. Affected areas would absorb the ultraviolet light and stand out with flourescent colors in the darkened room.

KEY TERMS

Melanin— A pigment that creates hair, skin and eye color. Melanin also protects the body by absorbing ultraviolet light.

Melanocytes— The type of skin cells that create melanin.

Albinism— An inherited condition that causes a lack of pigment. People with albinism typically have light skin, white or pale yellow hair and light blue or gray eyes

Hypopigmentation— A skin condition that occurs when the body has too little melanin, or pigment.

Hyperpigmentation— A skin condition that occurs when the body has too much melanin, or pigment.

Lichen simplex chronicus— A skin disorder with severe itching that causes thick, dark patches of skin to develop.

Vitilgo— A skin disorder that creates smooth, depigmented white spots on the skin.

Lamellar ichthyosis— Also called fish scale disease, this inherited condition is characterized by darkened, scaly, dry patches of skin.

Melasma— A dark mask-like discoloration that covers the cheeks and bridge of the nose. Also called "the mask of pregnancy."

Treatment

For albinism, healthcare providers advise people to cover up, use sunscreen and avoid excess sunlight to prevent skin cancer. People with albinism also must wear protective sunglasses and, in some cases, prescription corrective lenses. Surgery may be necessary to correct visual impairments.

To treat vitilgo, physicians may prescribe a combination of photo-sensitive medications like trimethylpsoralen and ultraviolet light therapy to darken the spots. If the person has depigmented patches covering more than 50% of the body, doctors also may be able to use skin bleaching agents like monobenzone to give the skin a lighter, more uniform appearance. Other options include cosmetic concealers and skin grafting.

Skin-lightening creams are available for hyper-pigmentation disorders. Doctors also advise staying out of the sun. Counseling with a dietitian may help in cases caused by poor nutrition. For lichen simplex chronicus, doctors could prescribe antihistamines and topical steroid creams to stop the itching. If a mole or birthmark appears suspicious, physicians often will surgically remove it to prevent skin cancer.

Prognosis

Most skin pigmentation disorders do not affect a person's health, only the outward appearance.

Prevention

In most cases, doctors will recommend using sunscreen and avoiding too much sun exposure.

Resources

PERIODICALS

Wilson, Tracy. "The Paler Side of Beauty." Heart and Soul 6, no. 1 (February 1999): 30-33.

ORGANIZATIONS

American Academy of Dermatology. 930 N. Meacham Road, P.O. Box 4014, Schaumburg, IL 60168-4014. (847) 330-0230. 〈http://www.aad.org〉.

National Organization for Albinism and Hypopigmentation (NOAH), 1530 Locust St., #29, Philadelphia, PA, 19102-4415. (800) 473-2310. 〈http://www.albinism.org〉.

OTHER

MelanomaNet. 〈http://www.skincarephysicians.com/melanomanet/index.html〉.

National Weather Service. "Ultraviolet Light Index." 〈http://www.nws.noaa.gov/pa/secnews/uv/index.html〉.

Skin infections

The skin is the largest organ in the human body. It is the front line of defense against many types of pathogens, and remains disease-free over most of its area most of the time. However, breaks in the skin are particularly prone to invasion by microorganisms , and skin infections are a relatively common complaint. Skin infections may be bacterial, viral or fungal in nature.

Among the more common bacterial skin infections is impetigo, a usually mild condition caused by staphylococcal or streptococcal bacteria . It causes small skin lesions and typically spreads among schoolchildren. Folliculitis results in pustules at the base of hairs or, in more serious cases, in painful boils. Often it is caused by Staphylococcus species. A relatively recent manifestation called "hot tub folliculitis" results from Pseudomonas bacteria in poorly maintained hot tubs. Those bacterial skin infections that do not resolve spontaneously are treated with topical or oral antibiotics .

Among the more serious bacterial infections of the skin is cellulitis, a deep infection involving subcutaneous areas and the lymphatic circulation in the region as well as the skin itself. The affected area is painful, red, and warm to the touch, and the patient may be feverish. Cellulitis is usually caused by bacterial invasion of an injury to the skin. Treatment includes oral and/or intravenous antibiotics, and immobilization and elevation of the affected area.

Viral skin infections typically show up as warts caused by the Human Papillomavirus (HPV). Common warts usually appear on the extremities, especially in children and adolescents. Plantar warts often grow on the heel or sole of the foot, surrounded by overgrown, calloused skin. When they develop on weight-bearing surfaces such as the heel, plantar warts may become painful. HPV also causes genital warts, or condylomata, which may increase the risk for cervical or penile cancer. Many methods are used in attempts to remove warts, with varying degrees of success. These include cryotherapy, antiviral agents, application of salicylic acid, surgical removal, and laser treatment.

Skin infections caused by fungi , including yeast , are called dermatomycoses. A common subcategory consists of the dermatophytoses, caused by Trichophyton species. These infections include tinea capitis ("cradle cap"), tinea corporis ("ringworm"), tinea cruris ("jock itch"), and tinea pedis ("athlete's foot"). Candida, which often affects the mucous membranes, may also be responsible for skin infections. Obese patients are prone to fungal infections in skin folds, as are uncircumcised men. Candida is also involved in some cases of diaper rash. Fungal infections are typically treated with topical imidazole creams or sprays.

See also Bacteria and bacterial infection; Candidiasis; Infection and resistance; Viruses and responses to viral infection; Yeast, infectious

Skin and Soft Tissue Infections

What Causes Skin and Soft Tissue Infections?

What Are Some Types of Skin and Soft Tissue Infections?

Are Skin and Soft Tissue Infections Contagious?

How Are Skin and Soft Tissue Infections Diagnosed?

Can Skin and Soft Tissue Infections Be Prevented?

Resources

Skin and soft tissue infections are infections involving the layers of the skin and the soft tissues beneath it.

KEYWORDS

for searching the Internet and other reference sources

Abscesses

Boils

Carbuncles

Cellulitis

Dermatology

Dermatophytes

Furuncles

Impetigo

Molluscum contagiosum

Necrotizing fasciitis

Ringworm

Tinea

Warts

What Causes Skin and Soft Tissue Infections?

Viruses, bacteria, and fungi generally cause skin and soft tissue infections by entering the body at a spot where a cut, scrape, bite, or other wound has broken the skin; some infections are even the result of bacteria that normally live on the body. These infections can affect the layers of the skin or deeper tissues, such as muscle and connective tissue (the interlacing framework of tissue that forms ligaments, tendons, and other supporting structures of the body), and they may bring about symptoms in other parts of the body.

Many infections like varicella (chicken pox) and measles (rubeola) affect the skin, but these infections involve the whole body and do not primarily arise within the skin or soft tissues.

What Are Some Types of Skin and Soft Tissue Infections?

Dermatophyte infections

Dermatophytes (dur-MAH-toh-fites) are fungi that live on the dead outer layer of skin. Sometimes they can produce symptoms of infection. Tinea (TIH-nee-uh) infections, commonly called ringworm (although they have nothing to do with worms), usually are caused by the Trichophyton group of these organisms. They include tinea pedis (PEE-dis), or athlete’s foot; tinea cruris (KRU-ris), or jock itch; tinea capitis (KAH-pih-tis), or ringworm of the scalp; tinea unguium (UN-gwee-um), or ringworm of the nails; and tinea corporis (KOR-poor-us), or ringworm of the body. Damaged skin is more vulnerable to infection, as is skin in warm, moist areas of the body. When the fungus takes hold, it typically causes a ring-like rash of red, flaking skin. The border of the rash may be raised, as if a worm were under the skin. The rash’s shape and this raised edge led people to call the infection ringworm. When the nails are infected, they usually become yellow, thickened, and brittle.

Tinea versicolor, or pityriasis (pih-tih-RYE-uh-sis) versicolor, is caused by the fungus Malassezia furfur. Symptoms include scaly patches of skin, ranging in color from light to dark. The patches occur on the chest, neck, back, underarms, and upper arms. Hot, humid weather encourages the growth of tinea versicolor. These fungal skin infections typically are treated with antifungal creams or ointments. In severe cases or when the infections do not improve with this therapy, several antifungal medications are available that may be given by mouth.

Impetigo

Impetigo (im-pih-TEE-go) refers to a skin infection in which there are red blister-like bumps that contain a yellowish fluid or pus*. After the blisters break open, they crust over. Impetigo is most common on the face, especially around the nose and mouth. Usually, either streptococcus (strep-tuh-KAH-kus) or staphylococcus (stah-fih-lo-KAH-kus) bacteria are the cause of the infection. Impetigo can spread easily, especially among children, who may scratch the lesions and then touch other areas of their skin or another person. People also can contract impetigo from handling clothing or blankets that have been in contact with infected skin.

*pus

is a thick, creamy fluid, usually yellow or greenish in color, that forms at the site of an infection. Pus contains infection-fighting white cells and other substances.

Doctors prescribe antibiotics to treat impetigo. The infection generally clears up without leaving permanent skin damage.

Skin abscesses

Skin abscesses (AB-seh-sez) may occur in areas of the skin where the body has been fighting a bacterial infection. To isolate the infection, the body forms a wall of tissue around the collection of pus, and this area is the abscess. Abscesses are usually round, raised, and red, and they may feel warm and tender. A furuncle (FYOOR-ung-kul), or boil, is an abscess that forms at the base of a hair follicle*. A carbuncle (KAR-bung-kul) forms when the infection spreads to include several follicles and the surrounding skin and deeper tissues. Like furuncles, carbuncles are red, raised, and sore to the touch.

*hair follicle

(FAH-lih-kul) is the skin structure from which hair develops and grows.

Most skin abscesses eventually burst to allow the pus to drain out, but treatment with antibiotics may be needed to clear up the infection in some cases. Skin abscesses that do not improve on their own need to be lanced (punctured and drained) by a doctor.

Cellulitis

Cellulitis (sel-yoo-LYE-tis) is an inflammation of the skin and/or the tissues beneath it. The culprits behind the infection are almost always group A streptococcus or Staphylococcus aureus (stah-fihlo-KAH-kus ARE-ree-us) bacteria. Cellulitis may occur in people with diabetes* or those who have immune system problems even if they do not have a skin injury. The infection can occur anywhere on the body, but it is found most frequently on the face and lower legs. It appears as tender, red, swollen areas of skin. The skin in the infected area may feel stretched and warm. A few days after the first symptoms, patients may experience fever, chills, and muscle aches. Red streaks also may appear on the skin, signaling the spread of the infection.

*diabetes

(dye-uh-BEE-teez) is a condition in which the body’s pancreas does not produce enough insulin or the body cannot use the insulin it makes effectively, resulting in increased levels of sugar in the blood. This can lead to increased urination, dehydration, weight loss, weakness, and a number of other symptoms and complications related to chemical imbalances within the body.

Antibiotics are used to treat cellulitis. Even after the infection is gone, the skin may look different for several weeks. Complications are rare, but they can include sepsis*, gangrene*, and lymphangitis*. Cellulitis may involve infection of deeper tissue called the fascia (FAY-she-uh). Infection in this layer can be very serious or even life threatening and often requires surgery to remove the infected tissue.

*sepsis

is a potentially serious spreading of infection, usually bacterial, through the bloodstream and body.

*gangrene

(GANG-green) is the decay or death of living tissue caused by a lack of oxygen supply to the tissue and/or bacterial infection of the tissue.

*lymphangitis

(lim-fan-JIE-tis) is inflammation of the lymphatic system, the system that carries lymph through the body. Lymph is a clear fluid that contains white blood cells.

Necrotizing fasciitis

Necrotizing fasciitis (NEH-kro-tie-zing fashe-EYE-tis), also called flesh-eating disease, is a rare but potentially fatal disease caused by group A streptococcus bacteria infection. It affects the deeper layers of skin and tissues beneath the skin. Necrotizing fasciitis starts with sudden painful swelling and discoloration (red, purple, or bronze) of the skin. Often, the appearance of the affected skin does not reflect how far the infection has spread into the deeper layers of tissue. The disease can spread rapidly, with the infected area growing larger and darker. The ability to feel in the infected area disappears as the skin tissue dies. As the infection quickly progresses, the patient can become very ill. Early treatment with antibiotics and surgery to remove the damaged tissue is extremely important. Recovery may take several months.

Molluscum contagiosum

Molluscum contagiosum (moh-LUS-kum kon-tay-jee-O-sum), caused by a virus, produces small, solid, dome-shaped bumps on the surface of the skin. They are flesh-colored and pearly with a dimple in the center. The growths are similar to warts. Viruses cause both conditions—poxvirus in the case of molluscum contagiosum and human papillomavirus in the case of warts. Growths can be single, but they most often appear in groups on the trunk, arms, legs, and genitals* and occasionally on the face.

*genitals

(JEH-nih-tuls) are the external sexual organs.

The disease usually clears up by itself over several months, although new growths may arise on the skin if the virus spreads through contact with infected areas. Doctors may recommend home treatment with over-the-counter medications or removal of the growths by freezing, surgery, laser therapy, or acid treatments.

Herpes Simplex Virus

There are two types of the herpes simplex virus (HSV): HSV-1 and HSV-2. Both can show up as skin infections. HSV-1 can cause small, clear blisters (also known as cold sores, fever blisters, or oral herpes) on the face, and HSV-2 can cause blisters in the genital area. These blisters can break, bleed, and crust over, leaving red spots of healing skin.

There is no cure for either HSV-1 or HSV-2. Currently, antiviral medications can help control outbreaks of herpes virus and are used to treat genital herpes or sometimes recurrent cold sores from HSV-1.

Warts

Warts are caused by human papillomavirus (pah-pih-LO-mahvy-rus), or HPV. They can be skin-colored, pink, tan, or white, and they may appear anywhere on the body. Common warts usually are seen on the hands (especially around the nails), feet, and face, because the virus spreads most easily to those areas. Common warts are rough and raised, but plantar warts, found on the soles of the feet, are flat. Unlike other warts, plantar warts can be painful.

Many warts disappear by themselves after months or even years. Treatments are available for those that do not, including over-the-counter medications or professional treatment by freezing, surgery, laser therapy, or acid treatments.

Are Skin and Soft Tissue Infections Contagious?

Necrotizing fasciitis, cellulitis, and abscesses are not contagious from person to person, but the bacteria that can cause these infections can spread between people. Dermatophytes, warts, and molluscum contagiosum spread fairly easily through skin-to-skin contact.

How Are Skin and Soft Tissue Infections Diagnosed?

A doctor examines the size, shape, and color of the affected area and checks it for tenderness and warmth. The doctor may order blood tests for cellulitis to assess the extent of the infection; tests of skin scrapings for suspected fungal infections or molluscum contagiosum; or tests on a tissue sample for necrotizing fasciitis. Doctors can use a special type of filtered ultraviolet light to check for tinea capitis because the fungi that cause it glow a characteristic color when the light is shined on the infected area.

Can Skin and Soft Tissue Infections Be Prevented?

The best way to prevent skin and soft tissue infections is to avoid getting cuts, scrapes, bites, or any kind of open wound. Frequent hand washing can curb the spread of bacteria. Doctors also advise keeping any opening in the skin clean and dry. It is wise to consult a doctor if the area around the wound becomes reddened, hot, or painful or if the infected person develops a fever. Dermatophyte infection is best avoided by keeping the skin dry, such as in areas where sweating occurs.

See also

Abscesses

Fungal Infections

Gangrene

Herpes Simplex Virus Infections

Ringworm

Sepsis

Skin Parasites

Staphylococcal Infections

Warts

Resources

Organization

American Academy of Dermatology, P.O. Box 4014, Schaumburg, IL 60168. The American Academy of Dermatology offers fact sheets and general information about various skin problems on its website. Information for young people can be found through the Kids’ Connection at the website.

Telephone 847-330-0230 http://www.aad.org

Website

KidsHealth.org. KidsHealth is a website created by the medical experts of the Nemours Foundation and is devoted to issues of children’s health. It contains articles on a variety of health topics, including cellulitis, impetigo, tinea, warts, and other bacterial, fungal, and viral infections.

http://www.KidsHealth.org

Skin Parasites

What Are Skin Parasites?

What Are Some Common Skin Parasites?

How Are Skin Parasites Spread?

Diagnosis and Treatment

Can Skin Parasites Cause Medical Complications?

How Can People Prevent Infestation with Skin Parasites?

Resources

Skin parasites (PAIR-uh-sites) are tiny organisms that invade the skin, often causing irritation and itching.

KEYWORDS

for searching the Internet and other reference sources

Chiggers

Lice

Mites

Nits

Pediculosis

Pediculus humanus capitis

Phthirus pubis

Pubic lice

Sarcoptes scabiei

Scabies

What Are Skin Parasites?

Parasites live off other living things (including people), often living, feeding, and reproducing on them. Some parasites thrive on human blood and cannot live long without it. When these parasites latch onto someone’s skin, they may lay their eggs there. Before long, that person could become the host (an organism that provides another organism, such as a parasite or virus, with a place to live and grow) for hundreds or more of the parasites.

Skin parasites are found worldwide and infest large numbers of people. For example, as many as 6 to 12 million people worldwide contract head lice every year, according to the U.S. Centers for Disease Control and Prevention. Head lice most often affect children in school and daycare settings.

What Are Some Common Skin Parasites?

There are many parasites that infest human skin, but lice, scabies (SKAY-beez), and chiggers are among the most common.

Head lice

Also known as Pediculus humanus capitis (peh-DIH-kyoolus HYOO-mah-nus KAH-pih-tis), head lice are six-legged parasites with tiny claws that cling to hairs. They are found on the scalp, neck, and behind the ears. Lice lay visible, whitish eggs called nits. In about 7 days, the nits hatch into young called nymphs (NIMFS). Nymphs grow up fast, and in just 1 week they mature into adult lice that must feed on blood to stay alive. Head lice may not cause any symptoms immediately, but as with other insect bites the body reacts to the invaders, leading to itching and sores from scratching.

Pubic lice

Pubic lice, or Phthirus pubis (THEER-us PYOO-bus), invade the pubic hair and sometimes other body hair such as beards, eyebrows, eyelashes, and armpit hair. They often are called “crabs” because of their crab-like appearance. Pubic lice cause intense itching, especially at night, when they feed by burying their heads into hair follicles*. The nits or adult lice can be seen on pubic hairs or surrounding skin.

*hair follicles

(FAH-lih-kulz) are the skin structures from hair develops and grows.

Scabies

Microscopic Sarcoptes scabiei (sar-KOP-teez SKAY-be-eye) mites cause an infestation called scabies. The mites work their way under the top layer of skin and lay their eggs. Most people are not even aware of the intruders until intense itching begins 2 to 6 weeks later. Red, pimple-like bumps appear on the skin, and there may be wavy lines on the skin tracing the mites’ paths, especially in the webbing between the fingers and in the skin folds at the back of the knees and the inside of the elbows.

Chiggers

Chiggers are mites that tend to live in weeds, tall grass, or wooded areas. The chigger larvae (LAR-vee, immature mites) feed on a variety of animals, including humans. The larvae crawl onto the skin of passersby and can use their tiny claws to grab onto human hair. They then attach to the skin, usually at the ankles or waist or in skin folds, with hooked mouthparts and feed on skin cells. Unlike lice and scabies, chiggers only feed on their host for a couple of days, then let go and fall off. Chigger bites can cause a red bump that continues to grow in size, a skin rash, hives*, and severe itchiness. Sometimes the larvae are visible in the center of the bump.

*hives

are swollen, itchy patches on the skin.

How Are Skin Parasites Spread?

Despite what many believe, people do not get skin parasites because of poor hygiene. Instead, skin parasites tend to spread in situations where they can walk or fall from one person to another (or in the case of chiggers, from vegetation to human skin). The parasites often require relatively prolonged and close contact to move between people, and they spread most easily in crowded conditions, from sharing personal items, and from skin-to-skin contact.

Head lice in particular fall easily onto their next victims in close quarters. They also can infest hairbrushes, barrettes, hats, and sometimes clothes or bed linens. If other people use these items, they can become infested as well. Pubic lice spread mostly through sexual contact, but people also can get them from bed linens and clothes.

Scabies spreads quickly in crowded living conditions or in places with lots of skin-to-skin contact (such as daycare centers and nursing homes). Like lice, scabies can be passed through sexual contact and by sharing clothes, towels, and bed linens.

Diagnosis and Treatment

Doctors often diagnose skin parasite infestations just by spotting the parasites, their eggs, larvae, or characteristic red bumps on the skin. With scabies, a skin scraping might be taken to check for mites, eggs, and mite feces (FEE-seez, or bowel movements). However, this test is not always accurate because the mites may have moved from the spot that was scraped.

Over-the-counter and prescription lotions and shampoos (known as pediculicides, peh-DIH-kyoo-lih-sides) can be used to kill head lice. In some cases, treatment may need to be repeated or replaced with stronger medications because lice are becoming resistant to some treatments. Other people living in the same house with the infested person may be treated at the same time.

Pubic lice also are treated with a pediculicide, similar to the treatment of head lice. If the infestation includes the eyelashes, petroleum jelly is applied several times a day to the eyelids for a week or more.

Patients with scabies are given medicated lotions to apply over the entire body, and the lotion must stay on for 8 to 12 hours. Chigger bites do not require any special treatment to heal, but antihistamines* may ease itching.

*antihistamines

(an-tie-HIS-tuh-meens) are drugs used to combat allergic reactions and relieve itching.

Infestation with lice and scabies can persist until they are treated properly. Once treatment begins, patients usually are no longer contagious after a day or two, but sores and itching may not disappear for a couple of weeks. Chigger bites heal quickly.

Can Skin Parasites Cause Medical Complications?

Complications of skin parasites are rare. Frequent or rough scratching of bites or sores can lead to bacterial infections, such as impetigo*. If lice spread to eyebrows or eyelashes, the eyelids may become infected. Norwegian or crusted scabies is a form of scabies that can be severe in people with weak immune systems, such as those with a chronic* illness and elderly people.

*impetigo

(im-pih-TEE-go) is a bacterial skin infection that usually occurs around the nose and mouth and causes itching and fluid-filled blisters that often burst and form yellowish crusts.

*chronic

(KRAH-nik) means continuing for a long period of time.

How Can People Prevent Infestation with Skin Parasites?

To avoid skin parasites, experts recommend that people:

• shower daily, wash hands frequently, and wear clean clothes
• avoid anyone who has lice or scabies until that person is treated
• never share brushes, hats, bed linens, or clothes
• practice abstinence (not having sex); birth control does not prevent pubic lice or scabies
• avoid chigger-infested areas and wear socks, long pants, and long sleeves in wooded or grassy areas

To prevent the spread of parasites in a home when a family member has been diagnosed with an infestation, it is wise to:

• wash bed linens, towels, and clothes in hot water, then dry them on high heat
• vacuum the entire house, then throw the vacuum cleaner bag away
• disinfect combs and hair items
• seal items that cannot be cleaned in airtight plastic bags for 2 weeks; at the end of that time, any parasites on those items will have died

In addition, children who have skin parasites should stay home from school or daycare until a day or two after they begin their treatment.

See also

Skin and Soft Tissue Infections

Resources

Organization

U.S. Centers for Disease Control and Prevention (CDC), 1600 Clifton Road, Atlanta, GA 30333. The CDC is the U.S. government authority for information about infectious and other diseases. It posts fact sheets about various parasitic infestations and diseases at its website.

Telephone 800-311-3435 http://www.cdc.gov

Website

KidsHealth.org. KidsHealth is a website created by the medical experts of the Nemours Foundation and is devoted to issues of children’s health. It contains articles on a variety of health topics, including lice, scabies, and chiggers.

http://www.KidsHealth.org

Skin Conditions

Leaves of Three, Let Them Be

What Does the Skin Do?

What Can Go Wrong?

What Are Some Common Skin Problems?

How Are Skin Conditions Diagnosed?

How Are Skin Conditions Treated?

The Skinny on Skin Care

Resources

Skin conditions include various rashes, diseases, infections, injuries, growths, and cancers that affect the skin.

KEYWORDS

for searching the Internet and other reference sources

Birthmarks

Dermatitis

Eczema

Herpes

Melanoma

Moles

Rash

Leaves of Three, Let Them Be

Alison loved to take long walks in the woods in the summer, but one day she developed a streaky rash two days after she had gone on a hike. At first, her skin was red and swollen in spots. Soon, however, little blisters formed and began to itch intensely. Alison had developed a rash from poison ivy. Her mother warned her not to scratch, because her fingernails might carry germs that could cause an infection. It was hard to resist, but cool showers and a soothing lotion helped. Within a few days, the blisters began to scab over. It took about 10 days for the rash to heal completely. Afterward, Alison was careful to wear long-sleeved shirts and long pants when walking in the woods and to stay away from poison ivy, identifiable by its clusters of three leaves.

What Does the Skin Do?

The skin is the largest and most visible organ of the body. It also is one of the most complex, because it has so much to do. The main job of the skin is to protect a person’s inside parts from the outside world. It acts as a shield against sun, wind, heat, cold, dryness, pollution, and cigarette smoke. All of these things can injure the skin over time. In addition, the skin comes into contact with and helps protect the body from germs; allergens (AL-er-jens), which are substances that can cause allergic reactions; and irritants, which are harsh chemicals that can hurt the skin. In addition, special nerve endings in the skin alert the brain to heat, cold, and pain.

Skin Deep

• The average adult body has two square yards of skin, which make up about 15 percent of the body’s total weight.
• A one-inch square of skin contains millions of cells as well as many special nerve endings for sensing heat, cold, and pain.
• The average thickness of skin is one-tenth of an inch, but it ranges from very thin on the eyelids to thick on the soles of the feet.

What Can Go Wrong?

It is not surprising that many things can go wrong with an organ so big and complicated. Allergens and irritants can make the skin break out in a rash. Dermatitis (der-ma-TY-tis) is a general term for red, inflamed skin from a variety of causes.

There also can be glitches in the way the skin works. For example, it can make too much oil, leading to acne (AK-nee). If the skin makes too many new cells, the result can be psoriasis (so-RY-a-sis). If the skin makes too little or too much coloring matter, called pigment, the result can be patches of abnormally light skin (hypopigmentation) or dark skin (hyperpigmentation).

The skin also can be affected by injuries, such as sunburn, and by viral infections, such as cold sores. Other kinds of skin infections are caused by bacteria and fungi. In addition, the skin can be affected by both noncancerous growths, such as birthmarks, and skin cancers.

What Are Some Common Skin Problems?

These are some of the most common skin problems seen by dermatologists (der-ma-TOL-o-jists), doctors who specialize in treating skin problems:

• Acne: pimples, blackheads, whiteheads, and deeper lumps. Almost all teenagers have at least a little acne, and some adults have the problem as well. Acne develops when the skin makes too much oil and sheds dead cells too fast. Bacteria also plays a role.
• Athlete’s foot: a fungal infection that may cause the skin on the foot to look red and peel, crack, flake, or even blister. Sweaty feet and tight shoes provide the perfect setting for a fungus to grow. Athlete’s foot is most common among teenagers and adult men.
• Atopic (ay-TOP-ik) dermatitis, also called eczema (EK-zem-ah): a red, itchy rash that often runs in families and accompanies allergies. In babies, it typically leads to itching, oozing patches with scabs, mainly on the face. In older children, the patches tend to be dry, and the affected skin may flake and thicken. In teenagers, the patches usually occur inside the elbow bends, backs of knees, ankles, wrists, face, neck, and upper chest.
• Birthmarks: a skin mark that develops before or shortly after birth. Several kinds of common birthmarks are caused by overgrowth of blood vessels. Such marks are usually painless.
• Cold sores: an infection caused by the herpes (HER-peez) simplex virus that leads to sores, usually around the mouth and nose. Some sores are barely noticeable, but others hurt. Cold sores are common among children and are easily spread from person to person by kissing or sharing dishes or towels.

BoTox and Wrinkle Relief

One of the drugs in the fight against wrinkles is called BoTox. BoTox, short for Botulism Toxin type A, is a byproduct produced by the bacterium Clostridium botulinum. In food, the bacterium causes a potentially fatal type of food poisoning known as botulism. To remove wrinkles, a small amount of BoTox is injected into the muscles under the wrinkled skin. The BoTox temporarily paralyzes the muscles and restricts their movement. The result, after 3 to 5 days, is that the wrinkles temporarily disappear. This is not a permanent treatment—it must be repeated every 3 months.

• Contact dermatitis: a red, itchy rash that occurs when the skin comes into contact with an allergen or something else to which the skin is sensitive. Examples include poison ivy and sensitivities to nickel, rubber, and skin care products.
• Dandruff: flaking of the skin on the scalp. Some flaking is part of the normal process by which the outer layer of skin cells is regularly shed. If the flaking becomes obvious on a person’s hair and clothes, it is called dandruff. If the scalp is red or if there are large flakes along with flaking elsewhere, the problem may be something else.
• Hives: pale red, swollen bumps that occur in groups on the skin. Hives are usually itchy, but they may also burn or sting. They are caused when the body releases a chemical called histamine (HIS-ta-meen) as part of a reaction to such things as foods, medications, insect bites, infections, cold, or scratching of the skin.
• Irritant dermatitis: a red, itchy rash that occurs when the skin comes into contact with a harsh chemical. Examples of irritants include strong soaps or detergents and industrial chemicals.
• Moles: growths that can appear anywhere on the skin, alone or in groups. They are usually brown and can have various shapes and sizes. Everyone has at least a few moles, and some people have forty or more. Most moles are not cancerous, but some may turn into a serious form of skin cancer called malignant melanoma (mel-a-NO-ma).
• Poison ivy: a common type of contact dermatitis that occurs when a sensitive person comes into contact with a substance found in the sap of poison ivy plants. Poison oak and poison sumac (SOO-mak) plants can have the same effect. The result is a streaky rash with redness and swelling, followed by blisters and itching. About 85 percent of all people will have this kind of allergic reaction to poison ivy.
• Psoriasis: a long-lasting skin disease caused when too many new cells are made, resulting in patches of red, thickened skin covered with silvery flakes. Four to 5 million Americans have psoriasis. It may result from a problem with the immune system, which normally fights germs and other foreign substances in the body.

• Ringworm: a skin infection caused by a fungus (not a worm). Ringworm is marked by red, itchy, ring-shaped patches that may flake or blister. It commonly affects the feet, scalp, trunk, nails, and groin.

Rash Thoughts

These are the medical terms for some common skin spots and bumps:

• Comedo (KOM-ee-do): a blackhead, whitehead, or pimple. Example: acne.
• Macule (MAK-yool): a small, flat, colored spot. Example: freckles.
• Papule (PAP-yool): a small, hard bump. Example: warts.
• Plaque (PLAK): a large, raised patch of skin. Example: psoriasis.
• Pustule (PUS-tyool): a pimple filled with pus. Example: acne.
• Wheal (WEEL): a short-lasting, swollen bump. Example: hives.

• Rosacea (ro-ZAY-she-a): a skin disease that causes redness and swelling on the face that may gradually spread to the cheeks and chin. Small blood vessels and tiny pimples may appear on or around the red area. Fair-skinned adults, especially women, are most likely to get rosacea.
• Seborrheic (seb-o-REE-ik) dermatitis: a common condition that causes red skin and greasy-looking flakes, mainly on the scalp, on the sides of the nose, between the eyebrows, on the eyelids, behind the ears, or on the chest. In babies, this condition is called cradle cap. In adults, it often occurs in people with oily skin and hair, and it may occur in those with acne or psoriasis.
• Shingles: a skin eruption caused by the same virus that causes chickenpox. It starts with pain or tingling on one side of the body or face, followed by a red rash with small blisters. After a person has chickenpox, the virus may live on in the nerve cells and come out years later as shingles. An episode of shingles may last weeks.
• Skin cancer: the most common of all types of cancer, including various kinds of growths on the skin. About 700,000 Americans get skin cancer each year. The main cause is the sun’s harmful rays.
• Sunburn: the immediate result of getting too much sun. The skin is injured, just as if it had been burned by heat, and turns red and painful. If the sunburn is severe, blisters may form. The long-term effects of sun damage include wrinkles, certain skin bumps and spots, and skin cancer.
• Vitiligo (vit-i-LY-go): a condition that causes white patches of skin due to a loss of pigment in the cells and tissues. It affects 1 or 2 out of every 100 people. Although vitiligo strikes people of all races, it is particularly noticeable in those with dark skin.
• Warts: small, hard bumps on the skin or inner linings of the body that are caused by a virus. Most are skin-colored, raised, and rough, but some are dark, flat, or smooth. Warts are common on the fingers, hands, arms, and feet. Some warts occur on the genitals and can be spread during sex.
• Wrinkles: a common sign of skin aging. The main cause of wrinkles is getting too much sun over a lifetime. Cigarette smoking also plays a major role.

How Are Skin Conditions Diagnosed?

Nearly everyone has a skin problem at some point in life. Such problems can affect anyone, from newborns to older adults. A doctor can identify many skin problems just by looking closely at the skin. The doctor may also ask about the person’s current symptoms, past illnesses, and family history.

In some cases, the doctor may need to do a biopsy (BY-op-see). This involves removing a small bit of skin so that it can be looked at under a microscope. If an infection caused by a fungus is suspected, the doctor may scrape off some skin flakes, which can be checked at a lab for signs of fungus. Another way to check for an infection caused by bacteria or a fungus is with a culture. This involves taking a sample from the site of possible infection and placing it in a nourishing substance called a medium to see what kind of bacteria or fungi grow.

If contact or allergic dermatitis is suspected, the doctor may do patch testing to find out what allergens are to blame. This involves putting tiny amounts of different substances on the skin under a patch. The skin is checked 2 days later to see which substances, if any, caused a reaction.

How Are Skin Conditions Treated?

• Medicines: Many medicines used to treat mild skin conditions are sold without a prescription in creams, lotions, gels, pads, and shampoos. Stronger medicines that are put on the skin, taken by mouth, or given in a shot are available only from a doctor or with a doctor’s prescription.
• Surgery: Doctors use several kinds of surgery to remove or destroy abnormal skin tissue. Excision involves removing a skin growth by cutting. Cryosurgery involves destroying a skin growth by freezing it with an extremely cold liquid such as liquid nitrogen. Electrosurgery involves destroying a skin growth by burning it with electricity. Laser surgery involves destroying skin tissue with a laser—a tool that produces a very narrow and intense beam of light. Surgery is used for such things as warts, skin cancer, moles, and birthmarks.
• Light therapy: Doctors treat certain skin problems with lamps that give off ultraviolet rays. In some cases, the person also takes a drug that makes the skin more sensitive to ultraviolet light. This therapy is used for such things as psoriasis and vitiligo.

The Skinny on Skin Care

These tips can help keep a person’s skin feeling healthy and looking its best:

• Protect the skin from the sun’s harmful rays. Avoid the midday sun, cover up with clothing, and use a good sunscreen with an SPF of 15 or higher.
• Wash the face gently with lukewarm water, a mild soap, and a washcloth or sponge to remove dead cells.
• Reduce dry skin by keeping baths short and using warm water. Use soap only as needed on the face, underarms, genitals, hands, and feet.
• Dry off the skin after bathing by brushing it lightly with the hands or patting it with a towel.

See also

Acne

Albinism

Allergies

Athlete’s Foot

Hives

Psoriasis

Ringworm

Skin Cancer

Vitiligo

Warts

Resources

Book Chapter

“Chapter 30. Your Skin.” In: David E. Larson, editor. Mayo Clinic Family Health Book, 2nd edition. New York: William Morrow, 1996.

Organizations

American Academy of Dermatology, P.O. Box 681069, Schaumburg, IL 60168-1069, (888) 462-DERM. A group of doctors who treat skin diseases. http://www.aad.org

American Society for Dermatologic Surgery, 930 N. Meacham Road, Schaumburg, IL 60173, (800) 441-2737. A group of doctors who do surgery on the skin. http://www.asds-net.org

National Institute of Arthritis and Musculoskeletal and Skin Diseases, 1 AMS Circle, Bethesda, MD 20892-3675, (301) 495-4484. A federal agency that studies skin diseases. http://www.nih.gov/niams