Updated

Despite a widespread belief that childhood eczema clears up by adolescence, a new study suggests the condition often lasts into adulthood.

Researchers followed kids with eczema over time and found that at least 80 percent of those surveyed at every age had the condition, up to age 26.

"This is a pretty persistent disease," Dr. David Margolis told Reuters Health. "Probably a lot of the adults that have dermatitis had it as children."

Margolis is the study's senior author from the Perelman School of Medicine at the University of Pennsylvania in Philadelphia.

Eczema is a common skin disorder, especially among children, marked by itchy, red skin. Between 10 and 20 percent of children experience symptoms of the condition, according to the National Institutes of Health.

"If you look at dermatologic textbooks over the past 20 years . . . it's pretty much assumed that by the time they're 10 or 12, the majority of them won't have symptoms anymore," Margolis said.

For the new study, he and his colleagues used data from a registry of eczema patients that have been followed since 2004, when they were between the ages of two and 17.

After they were enrolled in the trial, the children and teens received surveys through the mail every six months. Each survey asked if they'd had eczema symptoms within the last six months.

The study is funded by a grant from Valeant Pharmaceuticals, a company that makes a drug used to treat eczema.

The researchers found that at every age throughout the study - from two to 26 years - more than 80 percent of the participants reported eczema symptoms or were still using medications to treat the condition.

It wasn't until the participants were 20 years old that half of them had recorded at least one six-month period as being symptom- and treatment-free, they write.

"We're not saying that (people's eczema is) more severe or less severe," Margolis said. "We're just saying it's going to be a persistent problem that's probably not going to go away when they turn 10 or 12."

The results jibe with a recent study that found an equally high prevalence of eczema among adults as in children.

Dr. Jonathan Silverberg, an author of that study, wrote an editorial accompanying the new report in JAMA Dermatology.

It could be that asking people to report whether they have symptoms or are using any eczema treatments is a better way to estimate the condition's prevalence among adults than seeing whether they actually meet the clinical definition, he writes.

Alternatively, Silverberg told Reuters Health, it's possible that people with eczema drop off their doctor's radar because they had been unhappy with the available treatments.

"We now have a number of really promising therapies that are emerging that are really targeting eczema," said Silverberg, of the Feinberg School of Medicine at Northwestern University in Chicago.

"We're at a point now where our ability to manage eczema has gotten so much better that there is no reason for people to suffer with the itch and symptoms," he said.

Margolis said it's important for people who believe they have eczema to talk with their doctor about treatments.

"We're not saying you're going to have it every day of your life," he said. "These figures are saying you're going to have periods where it goes away."