Eczema is a term for several different types of skin swelling. Eczema is also called dermatitis. Most types cause dry, itchy skin and rashes on the face, inside the elbows and behind the knees, and on the hands and feet. Scratching the skin can cause it to turn red, and to swell and itch even more.

Eczema is not contagious. The cause is not known. It is likely caused by both genetic and environmental factors. Eczema may get better or worse over time, but it is often a long-lasting disease. People who have it may also develop hay fever and asthma.

The most common type of eczema is atopic dermatitis. It is most common in babies and children but adults can have it too. As children who have atopic dermatitis grow older, this problem may get better or go away. But sometimes the skin may stay dry and get irritated easily.

Treatments may include medicines, skin creams, light therapy, and good skin care. You can prevent some types of eczema by avoiding

• Things that irritate your skin, such as certain soaps, fabrics, and lotions
• Stress
• Things you are allergic to, such as food, pollen, and animals

Eczema, or atopic dermatitis, is an inflammatory skin condition that affects an estimated 30 percent of the U.S. population, mostly children and adolescents. It is a chronic disease characterized by dry, itchy skin that can weep clear fluid when scratched. People with eczema also may be particularly susceptible to bacterial, viral, and fungal skin infections.

A combination of genetic and environmental factors appears to be involved in the development of eczema. The condition often is associated with other allergic diseases such as asthma, hay fever, and food allergy. Children whose parents have asthma and allergies are more likely to develop atopic dermatitis than children of parents without allergic diseases. Approximately 30 percent of children with atopic dermatitis have food allergies, and many develop asthma or respiratory allergies. People who live in cities or drier climates also appear more likely to develop the disease.

The condition tends to worsen when a person is exposed to certain triggers, such as

• Pollen, mold, dust mites, animals, and certain foods (for allergic individuals)
• Cold and dry air
• Colds or the flu
• Skin contact with irritating chemicals
• Skin contact with rough materials such as wool
• Emotional factors such as stress
• Fragrances or dyes added to skin lotions or soaps.

Taking too many baths or showers and not moisturizing the skin properly afterward may also make eczema worse.

The skin of people with atopic dermatitis lacks infection-fighting proteins, making them susceptible to skin infections caused by bacteria and viruses. Fungal infections also are common in people with atopic dermatitis.

Bacterial Infections

A major health risk associated with atopic dermatitis is skin colonization or infection by bacteria such as Staphylococcus aureus. Sixty to 90 percent of people with atopic dermatitis are likely to have staph bacteria on their skin. Many eventually develop infection, which worsens the atopic dermatitis.

Viral Infections

People with atopic dermatitis are highly vulnerable to certain viral infections of the skin. For example, if infected with herpes simplex virus, they can develop a severe skin condition called atopic dermatitis with eczema herpeticum.

Those with atopic dermatitis should not receive the currently licensed smallpox vaccine, even if their disease is in remission, because they are at risk of developing a severe infection called eczema vaccinatum. This infection is caused when the live vaccinia virus in the smallpox vaccine reproduces and spreads throughout the body. Furthermore, those in close contact with people who have atopic dermatitis or a history of the disease should not receive the smallpox vaccine because of the risk of transmitting the live vaccine virus to the person with atopic dermatitis.

Skin Care at Home

You and your doctor should discuss the best treatment plan and medications for your atopic dermatitis. But taking care of your skin at home may reduce the need for prescription medications. Some recommendations include

• Avoid scratching the rash or skin.
• Relieve the itch by using a moisturizer or topical steroids. Take antihistamines to reduce severe itching.
• Keep your fingernails cut short. Consider light gloves if nighttime scratching is a problem.
• Lubricate or moisturize the skin two to three times a day using ointments such as petroleum jelly. Moisturizers should be free of alcohol, scents, dyes, fragrances, and other skin-irritating chemicals. A humidifier in the home also can help.
• Avoid anything that worsens symptoms, including
  • Irritants such as wool and lanolin (an oily substance derived from sheep wool used in some moisturizers and cosmetics)
  • Strong soaps or detergents
  • Sudden changes in body temperature and stress, which may cause sweating
• When washing or bathing
  • Keep water contact as brief as possible and use gentle body washes and cleansers instead of regular soaps. Lukewarm baths are better than long, hot baths.
  • Do not scrub or dry the skin too hard or for too long.
  • After bathing, apply lubricating ointments to damp skin. This will help trap moisture in the skin.

Wet Wrap Therapy

Researchers at NIAID and other institutions are studying an innovative treatment for severe eczema called wet wrap therapy. It includes three lukewarm baths a day, each followed by an application of topical medicines and moisturizer that is sealed in by a wrap of wet gauze.

People with severe eczema have come to the National Institutes of Health Clinical Center in Bethesda, Maryland, for research evaluation. Treatment may include wet wrap therapy to bring the condition under control. Patients and their caregivers also receive training on home-based skin care to properly manage flare-ups once they leave the hospital.

A patient at the NIH Clinical Center receives wet wrap therapy.

Credit: NIAID

Children with a skin disease called eczema benefited from an experimental treatment with live bacteria. The treatment improved skin symptoms in children as young as three years old.

Eczema can cause dry, itchy skin and rashes. Studies have shown that germs on the skin, like bacteria, may play a role in the condition. People with eczema often have a different balance of bacteria than those with healthy skin.

Researchers tested live bacteria as a treatment for eczema. They used bacteria found naturally on the skin called Roseomonas mucosa.

Twenty children were enrolled in the study. Their ages ranged from three to 16 years. A solution with the live bacteria was sprayed onto their skin where they had a patch of eczema. It was applied twice weekly for three months. Then, every other day for another month.

Almost all of the children showed more than 50% improvement in their symptoms after the treatment. Most needed less medicine to manage the condition. They also reported less itching and a better quality of life.

The scientists found improvements in the skin’s ability to seal in moisture. The treatment also helped keep out substances that can cause allergic reactions.

“Most children in the study experienced substantial improvements in their skin and overall wellbeing following R. mucosa therapy. Encouragingly, the bacteria stayed on the skin and continued to provide benefit after therapy stopped,” says NIH researcher Dr. Ian Myles, who led the study.

The treatment is now being further studied in a larger group of children, as well as adults.

You’ve probably had a rash at some point or another, whether from poison ivy or the chickenpox or something more unusual. Why does your skin break out in red blotches like that? More important, is there anything you can do about it?

We often think of the skin as a barrier—it keeps the insides of our bodies in, and it keeps the outside world out. But our skin is also filled with special cells of the immune system. These cells protect the skin and body against viruses, bacteria and other threats. Whenever these cells detect a suspicious substance, they begin a chain reaction in the skin that leads to inflammation. The medical name for this reaction is dermatitis. But it’s more commonly known as a rash.

There are many different types of dermatitis, and each has a distinct set of treatments. Sometimes the skin’s immune cells react to something that directly touches the skin. Other times, the immune system flares in the skin because of a whole-body infection or illness.

The symptoms of these different types of rashes often overlap. “Itching is a common symptom for all these problems,” says Dr. Stephen I. Katz, director of NIH’s National Institute of Arthritis and Musculoskeletal and Skin Diseases. Many rashes are red, painful, and irritated. Some types of rash can also lead to blisters or patches of raw skin. While most rashes clear up fairly quickly, others are long lasting and need to be cared for over long periods of time.

Eczema, or atopic dermatitis, is a dry, red, itchy rash that affects up to 1 in 5 infants and young children. It often improves over time, although it can last into adulthood or start later in life. In this condition, the water-tight barrier between skin cells gets weak, which lets moisture out and other things in. That’s why people with atopic dermatitis have to moisturize their skin, and they’re more susceptible to skin infections.

Researchers have recently identified specific genes that are involved in maintaining the skin barrier. People with certain versions of these genes are more likely to get atopic dermatitis.

“The skin is the outermost sentinel for fighting off bacteria and noxious agents,” says Katz. “If the barrier is broken somehow, you can become more allergic to things.”

A skin allergy, or allergic contact dermatitis, produces a red, itchy rash that sometimes comes with small blisters or bumps. The rash arises when the skin comes in contact with an allergen, a usually harmless substance that the immune system attacks. Allergens trigger allergic reactions. Allergens can come from certain soaps, creams and even pets.

Your immune system might not react the first time you encounter an allergen. But over time, your immune system can become sensitive to the substance. As a result, your next contact may lead to inflammation and an allergic rash.

“The most common form of dermatitis that is seen anywhere is an allergic contact dermatitis to nickel,” says Katz. “Why? Because of ear piercing.” Many inexpensive earrings are made of nickel, and over time, wearing nickel earrings can cause an allergic reaction to the metal.

Other common causes of allergic dermatitis are poison oak and poison ivy. The stems and leaves of these plants produce a chemical that’s likely to cause allergies. If you touch one of them, wash your skin as soon as possible. The chemical can also remain in clothing for a long time, so it’s important to wash any clothes or shoes—or even pets—that come into contact with these plants.

Mild cases of allergic contact dermatitis usually disappear after a few days or weeks. But if the rash persists, is extremely uncomfortable or occurs on the face, it’s important to see a physician. A doctor can prescribe medications that will tone down the immune reaction in the skin. This eases swelling and itching and will protect your eyes and face.

The immune cells of the skin can also produce rashes when they react to invading germs—like bacteria, fungi and viruses. Bacterial and viral infections within your body can cause your skin to break out in spots as well. The chickenpox virus, for example, can cause itchy spots in children. Years later, in older adults, the same virus may reappear as shingles, bringing a painful rash and high fever. Vaccines can prevent several rash-causing diseases, including chickenpox, shingles and measles.

Certain drugs, including antibiotics like amoxicillin, may also cause itchy skin rashes. If you’re allergic to a drug, a rash can be the first sign of a serious reaction. As with other allergies, a reaction to a drug may not occur the first time you take it. It could show up after several uses. Not all drug rashes are due to an allergy, however. If you break out in itchy spots after starting a new drug prescription, contact your doctor right away.

While most rashes get better with time, some can last a lifetime. Psoriasis, a condition where skin cells build up into thick red patches, tends to run in families. “It’s a complex genetic disease, in that there’s not one gene that causes psoriasis but many,” says Katz. Even though none of these genes alone has a great effect on the disease, knowing which genes are involved can help researchers design potential new treatments. Other long-term diseases that can produce rashes include autoimmune diseases, such as lupus, and some forms of cancer.

If you notice an itchy or painful rash on your skin, think twice before going to the drugstore and getting some cream if you don’t know the cause. “The creams that you buy can produce problems that make your original problem even worse,” Katz says. Because rashes can be caused by many different things—bacteria, viruses, drugs, allergies, genetic disorders, and even light—it’s important to figure out what kind of dermatitis you have.

“If you have any significant rash, you should see a dermatologist,” says Katz. A dermatologist, or skin doctor, is specially trained to figure out what’s causing a rash and help you get the right treatment.

Your skin is your protection. It’s not just the covering that keeps your body in; it’s also your first line of defense against germs and chemicals. Take care of your skin so your skin can take care of you.

Call Your Doctor If …

• Your rash is so uncomfortable or painful it interferes with daily activities or sleep.
• The rash is on your face.
• Your rash looks worrisome or seems infected.
• You break out in a rash after taking a new medication.
• Your rash lasts for several days.