Eczema

Eczema Overview

Eczema is a group of conditions that cause inflammation of the skin.

Typically, eczema causes skin to become itchy, red, and dry — even cracked and leathery. Eczema can appear on any part of the body.

Eczema is a chronic problem for many people. It’s most common in infants, many of whom outgrow it before adulthood.

People with eczema have a higher risk of having allergic conditions like asthma or hay fever.

Atopic dermatitis is the most common of the many types of eczema.

Eczema runs in families. Certain genes can cause some people to have extra-sensitive skin. An overactive immune system is thought to play a part, too. And some people think that defects in the skin contribute to eczema. These defects can allow moisture out through the skin and let germs in.

Things that may trigger eczema include:

• Stress
• Contact with irritating substances such as wool, synthetic fabrics, and soap
• Heat and sweat
• Cold, dry climates
• Dry skin

What Are the Symptoms of Eczema?

Almost always, your skin will itch before a rash appears in eczema.

Typically, eczema shows itself as:

Patches of chronically itchy, dry, thickened skin, usually on the hands, neck, face, and legs (but it can occur anywhere). In children, the inner creases of the knees and elbows are often involved.
If scratched, dry patches of skin and open sores with crusts may develop and may get infected.

Call Your Doctor About Eczema If:

• You develop an itchy rash and have a family history of eczema or asthma.
• The inflammation doesn’t respond within a week to treatment with over-the-counter hydrocortisone creams. You may need more aggressive forms of treatment.
• You develop yellowish to light brown crust or pus-filled blisters over existing patches of eczema. This may indicate a bacterial infection that should be treated with an antibiotic.
• During a flare-up of eczema, you are exposed to anyone with a viral skin disease such as cold sores or genital herpes. Having eczema puts you at increased risk of contracting the herpes simplex virus.
• You develop numerous painful, small, fluid-filled blisters in the areas of eczema. You may have eczema herpeticum, a rare but potentially serious complication caused by the herpes simplex virus.

Doctors don’t know exactly what causes eczema. The most common type of eczema — atopic dermatitis — resembles an allergy. But the skin irritation, which is more often seen in children rather than adults, is not an allergic reaction.

The current thinking is that eczemais caused by a combination of factors that include:

• Genetics
• Abnormal function of the immune system
• Environment
• Activities that may cause skin to be more sensitiveDefects in the skin barrier that allow moisture out and germs in

 

What We Know About the Causes of Eczema

Here’s more detail on what’s known about eczema causes:

Eczema is not contagious. You or your children can’t catch eczema by coming in contact with someone who has it.

Eczema runs in families. That suggests a genetic role in eczema’s development. A major risk factor is having relatives who have or had:

• Eczema
• Asthma
• Seasonal allergies such as hay fever

Doctors also know that a large percentage of children with severe eczema will later develop asthma or other allergies.

Mother’s age at time of birth. It’s not clear why, but children born to older women are more likely to develop eczema than children born to younger women.

Role of environment. Children are more likely to develop eczema if they:

• Are in higher social classes
• Live in urban areas with higher levels of pollution
• Live in colder climates

Eczema is not an allergic reaction. Even so, a large number of children who have eczema also have food allergies. That doesn’t mean that certain foods such as dairy, eggs, and nuts — common food allergy triggers in children with eczema — cause it or make it worse. Before removing particular foods from your child’s diet, talk with your health care provider to be sure your child’s nutritional needs will be met.

The Role of Triggers in Eczema

A trigger is not something that causes eczema. But it can cause it to flare or make a flare worse.

The most common triggers are substances that irritate the skin. For instance, in many people with eczema, wool or man-made fibers that come in contact with the skin can trigger a flare.

Examples of other things that can irritate the skin include:

• Soaps and cleansers
• Perfume
• Makeup
• Dust and sand
• Chlorine
• Solvents
• Irritants in the environment
• Cigarette smoke

Flares can also be triggered by certain conditions that have an effect on the immune system. For instance, things that can trigger or worsen a flare include:

• Cold or flu
• Bacterial infection
• Allergic reaction to something such as mold, pollen, or pet dander​
• Stress has also been identified as a possible trigger

Actions and environments that cause the skin to dry out or become otherwise sensitive can trigger flares. Some examples include:

• Prolonged exposure to water
• Being too hot or too cold
• Sweating and then becoming chilled
• Taking baths or showers that are too hot or last too long
• Not using a skin lubricant after a bath
• Low humidity in the winter
• Living in a climate that is dry year-round

Eczema is a common problem that causes the skin to become inflamed. People often also call it dermatitis.

Eczema​ ​comes in many forms. But the different types of eczema tend to cause these symptoms:

• Itching . The itching can be intense. The damage to the skin during eczema is often due to scratching.
• Scaling. The surface of the skin can flake off, giving the skin a rough, scaly appearance.
• Redness. The affected skin may bleed and appear blotchy.
• Fluid-filled blisters. These can ooze and form crusts.
• Cracking. Severely affected skin may develop painful, deep cracks, also called fissures.

Depending on the cause, eczema may flare up and cause severe symptoms. But it can also become a chronic problem with less intense symptoms.

Here’s a look at the types of eczema and their treatments.

Atopic Dermatitis

Atopic dermatitis is the most common form of eczema. It often affects people who also have:

• Asthma or hay fever
• Family history of eczema, asthma, or hay fever
• Defects in the skin barrier, allowing moisture out and germs in

Atopic dermatitis usually begins during infancy or childhood. But it can strike people at any age.

Most often, it affects skin on the:

• Face
• Hands
• Feet
• Inner elbows
• Back of the knees

Over time, scratching the skin can cause it to become thick and red. Scratching can also create wounds that become infected. Irritants that can make symptoms of atopic dermatitis worse include:

• Soap
• Rough clothing
• Household chemicals
• Foods, dust mites, and other allergy
• Triggers can also make symptoms worse.

Treatments for atopic dermatitis include:

• Products to lubricate and moisturize the skin
• Steroid creams and ointments
• Drugs that control the immune system including dupilumab (Dupixent), which is given as an injection every two weeks, and crisaborole (Eucrisa), a non-steroidal ointment that is used topically twice a day.
• Antibiotics to treat infections
• Ultraviolet light, alone or with a drug called psoralen

Irritant contact dermatitis can develop after touching a strong irritant one time or by coming into contact with the irritating substance repeatedly.

Contact dermatitis can also develop after a person touches an allergy-triggering substance, such as:

• Nickel
• Cosmetics
• Poison ivy

The hands are especially vulnerable to developing contact dermatitis. People can develop contact dermatitis even if they don’t have atopic dermatitis.

Treatments for irritant contact dermatitis include:

• Moisturizers for the skin
• Steroid medications

Treatments for contact dermatitis from allergic triggers also include steroid drugs. These are rubbed on the skin or taken as a pill.

For either type of contact dermatitis, antibiotics may be necessary. Avoiding future contact with the irritant or allergy trigger is also important. Wearing gloves can help protect the skin on the hands, which are often affected.

Dyshidrotic Dermatitis

This type of eczema affects the hands and feet. The cause is unknown.

The first symptom may be severe itching. Blisters may then appear, which give way a few weeks later to scaly patches. Sometimes deep cracks can appear on the hands or fingers.

This type of eczema may become chronic and painful.

Contact Dermatitis

There are two types of contact dermatitis:

1. Irritant contact dermatitis
2. Allergic contact dermatitis

These types of eczema can develop after a substance damages the skin. These include chemicals and frequent hand washing.

Nummular Dermatitis

This type of eczema more often affects men than women. Men usually don’t get their first outbreak before their mid-50s. Women tend to get it in their teen years or early adulthood.

Nummular dermatitis causes coin-shaped red marks. The marks appear most often on the:

• Legs
• Backs of the hands
• Forearms
• Lower back
• Hips

The cause of nummular dermatitis is unknown. However, factors that may raise the chance that an outbreak will strike include:

• Cold, dry air
• Exposure to chemicals such as formaldehyde
• Exposure to metals, including nickel

Treatments for nummular dermatitis include:

• Protecting your skin from scratches and other injuries
• Taking a lukewarm bath or shower, then applying a moisturizer to your skin
• Applying a steroid ointment to the rash
• Taking a steroid medication by mouth or injection that goes to work throughout your body
• Taking antibiotics if an infection develops

Neurodermatitis

People with this type of eczema develop skin irritation in spots that they frequently scratch out of habit.

This type of eczema often affects these areas:

• Back
• Sides or back of the neck
• Genitals
• Scalp
• Wrists
• Ankles
• Inside and behind the ear

People may scratch affected areas during the day without realizing it. They may also scratch while asleep.

Usually, neurodermatitis causes a skin outbreak that doesn’t get any bigger. But the irritated skin can grow thick and deeply wrinkled. Infections may also develop in the irritated areas.

The main treatment for this type of eczema is to stop scratching it. In the meantime, steroid medicines that are rubbed onto the skin can help treat symptoms.

When neurodermatitis affects the scalp, it can be harder to treat. In these cases, it may require the steroid medication prednisone, which is taken by mouth.

Seborrheic Dermatitis

This type of eczema is better known as dandruff. In infants, it affects the scalp. In adults, it also often affects these areas:

• Eyebrows
• Sides of the nose
• Area behind the ears
• Groin
• Center of chest

Seborrheic dermatitis causes skin to fall off in flakes. The condition may be due to an overgrowth of a type of yeast that normally lives in these areas, as well as an overgrowth and rapid shedding of cells on the scalp. It may be especially hard to treat in people whose immune systems aren’t working properly, including people with AIDS .

Treatments vary between infants and people with the condition later in life. The treatments include:

• Shampoo containing salicylic acid, selenium sulfide, zinc pyrithione, or coal tar
• Antifungal treatments that are rubbed onto affected areas
• Steroid lotions

Stasis Dermatitis

This type of eczema can develop in people when the veins in their lower legs don’t properly return blood to their heart.

Stasis dermatitis can arise quickly, causing weeping and crusting of the skin. Over time, this type of eczema can cause the skin to develop brown stains.

Treatments include:

• Steroid creams or ointments
• Creams or lotions that lubricate the skin
• Moist compresses
• Antibiotics to treat infections
• Elevating the legs
• Compression stockings​

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