What Causes Eczema?

Eczema is a skin condition that shows up as itchy, dry, red patches, and can result in peeling, blisters, and sores. According to the National Eczema Association, it affects more than 30 million Americans. Eczema tends to show up in childhood, usually on the cheeks, chin, elbows, or knees, and symptoms usually lessen over time.

Still, some people will have eczema as they grow older, and adults can develop it as well. It's tricky to narrow down exactly what causes eczema, since there are so many different forms of the condition, and different triggers can exacerbate each type. For example, allergens such as pet dander or pollen could cause the irritating rash to appear, or it could be linked to other health conditions such as high blood pressure. For most forms, the cause isn't clear and it's linked to a combination of factors.

What researchers do know, however, is that the most common form of eczema, atopic dermatitis (AD), seems to be passed down in families, says Debra Jaliman, MD, a dermatologist in New York City. It's also part of the atopic triad, three common conditions that are linked together (though they may not necessarily show up in people at the same time): AD, asthma, and hay fever. If your family has a history of asthma or hay fever, you're more likely to develop AD.

With this particular kind of eczema, something has triggered the immune system, which then goes into overdrive, causing skin irritation. The symptoms usually improve and worsen in waves (called flare-ups), but there's no cure and it never totally goes away. Symptoms vary from person to person, and although some people are able to manage their eczema, it can be more difficult to treat for others.

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What are the other kinds of eczema?

According to the National Eczema Association, there are six types of eczema, including AD. These are the other forms:

• Contact dermatitis: This form is caused by an irritating substance, like chemicals, detergents and some skin care products.
• Dyshidrotic eczema: This causes blisters on the hands and feet and is brought on by irritants as well as stress, allergies, and damp feet and hands.
• Hand eczema: This form is triggered by irritating substances, and is also linked to family history.
• Neurodermatitis: This causes rough, dry, thick patches of skin, thought to be triggered by stress or bug bites.
• Nummular eczema: This type presents as small, itchy spots, possibly brought on by dry winter skin, bug bites, or inflammation.
• Stasis dermatitis: This is usually caused by blood pressure issues, which can lead veins to leak and cause skin irritation.

What can make eczema symptoms worse?

Several factors can make eczema symptoms worse. Basically, anything that's drying or non-hypoallergenic can aggravate symptoms, since the skin barrier is already irritated. Here's what to watch out for:

• Long, hot showers (hot water saps the skin of natural oils)
• Harsh skincare and soaps
• Dry winter weather
• Allergens such as pollen, pet dander, and dust mites
• Stress
• Chlorine
• Perfumes/products with fragrance
• Chemicals (hair dye, nail polish)
• Scratchy, irritating fabrics (stick to natural fibers like cotton)

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How is eczema treated?

Dr. Jaliman recommends using a mild cleanser made for sensitive skin and following with a moisturizer, particularly one with shea butter, hyaluronic acid, glycerin, or ceramides, to help rebuild the skin's protective barrier. Using a humidifier while you sleep can also help put moisture back into the air and your skin, she says.

There's also the option of prescription topical steroids or creams, which can help for a short period of time, says Amanda Doyle, MD, of Russak Dermatology in New York City. For an over-the-counter solution, she recommends Vaseline Intensive Care Advanced Repair Hand Unscented Lotion, as it's accepted by the National Eczema Association as a safe option for eczema-prone skin. You can see more of the association's product recommendations here.

For those who aren't able to manage their symptoms with topical treatments, the FDA recently approved a new injectable drug to help alleviate symptoms like itchiness.

New York City dermatologist Francesca Fusco, MD, says to look for gentle soaps, like Dove or Caress, and to moisturize rough patches with Vaseline. For eczema on the scalp, she recommends Dove DermaCare Scalp Dryness and Itch Relief Anti-Dandruff Shampoo—the zinc pyrithione hydrates and gets rid of flakes.