Eczema Isn’t Contagious, But You Might Have Your Parents to Thank If You Have It

One of the most head-scratching myths about eczema, an atopic skin disease affecting 31.6 million Americans, is that you can “catch” it from someone. This is completely untrue.

How your genes and environment conspire to keep you up scratching all night

Eczema is not a contagious disease – it’s a skin condition you can inherit from your parents; if you have the genes for eczema, the disease can become activated in the presence of environmental allergens or triggers. An eczema trigger is something in your environment that passes through your skin’s outermost layer – the skin barrier – and then causes itchy skin, inflammation and possibly infection. Still, it’s impossible to “catch” eczema from someone else – it always starts within your own DNA.

“There’s a very strong genetic component to this disease,” said Dr. Jeff Yu, assistant professor of dermatology at Massachusetts General Hospital. “When someone has eczema, there is almost always a family history of the disease.”  According to Dr. Yu, if both parents have a history of eczema, there’s a 50% chance their child will have eczema, too. Knowing it’s genetic, however, doesn’t always help destigmatize the visible symptoms of the disease. 

For some people, kids especially, it’s helpful to compare eczema to another genetic condition that we inherit from our parents: freckles. The same way that some people have freckles and others do not, the genetic code we receive from our parents determines the texture, thickness and composition of our skin barrier. For instance, if your mom’s facial skin is covered in freckles, you might end up with freckles on your cheeks, too – or maybe not. The genetic code for expressing freckles on your body is activated by exposure to the sun. 

This same interaction between our genes and our environment takes place with eczema. Ourskin can become triggered by pollution in the air we breathe, or by chemicals in the water we drink, toxins in the food we eat or irritating fibers in the fabric on our skin. For some people, the triggers are obvious (no more spray-on sunscreen!); while others are more elusive (who knew that the nickel in your silverware could cause a flare?); and for some people, environmental triggers can change over time, further complicating treatment.

Why are some people lucky enough to avoid eczema, even when their parents have it?

“When researchers looked at twins,” Dr. Yu explained, “there was roughly a 75% chance that if one twin had eczema, the other twin would have it, too.” That indicates a complicated interaction between our genes and environment; for someone with a low genetic predisposition – say, Dad has moderate eczema but Mom doesn’t, for instance – the environment would need to play a more active role in triggering the disease, and, for the lucky few, that doesn’t always happen.

Wherever you live, there are dozens of environmental variables that increase or decrease your risk for developing eczema, including: whether you live in an urban or rural setting, your diet, your exercise routine, your sleep schedule, stress, exposure to UV light, whether you live in a humid or dry climate – the list of potential triggers goes on forever and varies for everyone.

Reminder: eczema is not contagious

Remember: you can’t catch freckles just by giving someone a hug. Same thing with eczema. You can’t catch someone else’s dry itchy skin, or scaly patches or inflammation, just because you’re close to them, or even touching them. Eczema is not contagious, no matter what.