Let's Talk About the Causes of Eczema
Keep this mantra in mind: You didn’t catch or cause your eczema. Stick with us as we scratch beneath the surface of this confusing condition to give you a deeper understanding of why it happens in the first place.
Which came first, the chicken or the egg? Who built Stonehenge? Like some of life’s greatest mysteries, the exact cause of eczema remains unsolved. However, doctors believe genetics are a main suspect—meaning some people with a family history of the disease are at a higher risk for developing it, as well as those who have allergic conditions like hay fever, asthma, or food allergies. Then there are the triggers—things like dry skin, environmental changes, common household products, and stress, which can propel eczema into a fiery rage. Understanding the factors that can cause eczema to develop and knowing your triggers can help you battle symptoms like a boss.
Our Pro Panel
We went to some of the nation's top experts in eczema to bring you the most up-to-date information about causes possible.
Bruce A. Brod, M.D., FAAD
Clinical Professor of Dermatology
University of Pennsylvania Perelman School of Medicine
JiaDe Yu, M.D.
MGH Contact Dermatitis and Occupational Dermatitis Clinic at the Massachusetts General Hospital/Harvard Medical School
Cheryl Bayart, M.D.
Nope. This is a common misconception. Just because your skin is parched, as if it hasn’t had a drink of water in a year, does not mean you’ll get eczema. Dry skin can make existing eczema worse, though, because the drier your skin, the more it will itch.
No. In fact, some experts believe that people in very clean environments who are not exposed to dust and dirt are more likely to develop eczema. This is no excuse to skip the shower or bath, though. Bathing can help minimize symptoms by pumping moisture into the surface layers of skin.
Actually, according to studies, there is a possible link between early exposure to cigarette smoke and adult onset eczema. Researchers believe one reason may be because smoke directly weakens the skin barrier.
No, although this can be confusing. If you do have eczema, research shows you may also develop other atopic conditions. Half of patients with moderate to severe eczema also suffer from asthma, hay fever, or food allergies.
A Quick Eczema Recap (In Case You Need a Refresher!)
Eck-zeh-ma: It’s as hard to say as it is to understand. For those 30 million people in the U.S with this chronic condition, the struggle is real thanks to red, inflamed skin that can itch like your body is one big mosquito bite.
Kind of like an unsolved crime, researchers have yet to crack the case on eczema completely. Here are the facts:
It can affect anyone from infants to grandparents.
Its symptoms don’t always look the same.
There are seven different varieties.
There is no cure.
The other piece of this puzzle: The exact cause remains largely unknown, however, the main suspect is genetics. Now that you have the evidence, let’s get down to the itchy gritty details for why you get eczema in the first place.
Is Eczema Genetic?
As if you needed another thing to blame on your parents: Eczema is likely to be an inherited condition. Approximately 70% of people with eczema have a family history of atopic diseases (eczema, asthma, hay fever, and food allergies, also known as the allergic march).
In fact, having a parent with one of these conditions makes your chances of developing eczema two to three times higher. And if both parents have one of them, your risk increases by three to five times (sorry, we’re just the messenger). But don’t panic just yet: Even if both of your parents have eczema, it’s still not a guarantee that you will, too.
Research also shows that some people with eczema have a mutation of a certain gene (the one responsible for creating filaggrin, a protein that keeps the top layer of the skin strong). The mutation means they these folks have a weak epidermis, so moisture has an easy way out from the skin and bacteria and viruses have a one-way ticket in. This is often the reason why people with eczema tend to have very dry and infection-prone skin. Those with this gene mutation also seem to have earlier onset eczema that’s often more severe and persistent.
While there is no cure for eczema, some people with childhood onset may see their symptoms improve or change in character as they get older—sometimes flaring and at other times being relatively quiet, though the underlying genetic predisposition does not seem to change. We know, it’s complicated.
What Are Some Eczema Triggers?
Just like the little kid who kicks the back of your airplane seat the entire flight, eczema triggers know how to get under your skin (or in this case, on top of it). It's not even that hard to do: There are the things in the environment, in your household, in your day-to-day, even in your body that can cause eczema symptoms to rage. Because those with eczema often have an over-reactive immune system, when they’re exposed to a certain trigger, the body responds with inflammation.
Keep in mind, not everyone who has eczema has the same triggers, (yup, it’s tricky like that) but there are a host of common culprits to watch out for. It can take some detective work to figure out your personal repeat offenders, which often means finding out by way of exposure so you know to avoid them going forward.
In the meantime, here are the common triggers that tend to wreak the most havoc:
The weather: Low humidity can cause the skin to become dry and itchy, while conversely, high heat and humidity can cause skin to sweat, which can make itching worse.
Dry skin: The drier your skin, the more likely your eczema will rear its red, scaly head.
Skin irritants: These could be common products in your home like disinfectants, soap, body wash, or shampoo that can irritate your skin and cause burning, itching, or redness when you encounter them. Other irritants include metals, especially nickel (commonly used for earring backings), fragrances, fabrics such as polyester or wool, cigarette smoke, and formaldehyde, which is found in disinfectants, glues, and adhesives.
Allergens: The substances that commonly trigger an allergic reaction (think: pollen, dust mites, pet dander, and mold) and lead to sneezing, itching, watery eyes, and a stuffed or runny nose, can also spark or worsen eczema symptoms.
Stress: According to studies, stress has been shown to trigger flareups in some people with eczema. This is due, in part, to stress causing an inflammatory response, which aggravates the condition. This inflammation can also negatively affect the skin barrier function, leading to more moisture loss and an increased susceptibility to infection.
Skin infection: Common bacterial infections like staphylococcus aureus (staph) and viral infections such as herpes simplex virus (HSV), the virus that causes cold sores, have been shown to cause eczema flareups.
Hormone fluctuations: During pivotal moments in a woman life, like just before and during your period, during and following pregnancy, and as you transition to menopause, hormones fluctuate and can trigger eczema flareups. These flucuations can also make existing symptoms worse, because a drop in estrogen can cause skin to lose water, leading to dryness and itchiness.
Assessing Severity of Eczema: Journal of the American Academy of Dermatology. (2014). “Guidelines of care for the management of atopic dermatitis.” jaad.org/article/S0190-9622(13)01095-5/fulltext
The Cause of Eczema & the Impact of Triggers: Center for the Study of Itch, Department of Medicine, Division of Dermatology, Washington University in St. Louis School of Medicine. (2019). “Atopic Dermatitis Clinical Presentation.” emedicine.medscape.com/article/1049085-overview#a7
The Effect of Cigarettes on Eczema: Journal of the American Academy of Dermatology. (2016). “Association of atopic dermatitis with smoking: A systematic review and meta-analysis.” ncbi.nlm.nih.gov/pmc/articles/PMC5216172/
Filaggrin and Eczema: The Journal of Allergy and Clinical Immunology. (2017). “Proteomic analysis of filaggrin deficiency identifies molecular signatures characteristic of atopic eczema.” jacionline.org/article/S0091-6749(17)30471-2/fulltext
Stress and Eczema: Current Allergy and Asthma Reports. (2008). “Stress and Atopic Dermatitis.” link.springer.com/article/10.1007/s11882-008-0050-6
Staph Infections and Eczema: Future Microbiology. (2017). “What is the role of Staphylococcus aureus and herpes virus infections in the pathogenesis of atopic dermatitis?” ncbi.nlm.nih.gov/pubmed/29052452