Doctors have long thought that kids with eczema usually grow out of the disease, but a study published today in the journal JAMA Dermatology now shows that's far from typical.

David Margolis, a University of Pennsylvania dermatologist and epidemiologist who led the latest study, said in kids, the itchy red patches that characterize the condition are often found in elbow or knee creases.

"Those patches can be small, and almost coin sized, or they can be larger," said Margolis. "Sometimes people itch so much that they cause pigment change to their skin or their skin gets thickened over time, as well."

Margolis and his team tracked more than seven thousand kids diagnosed with mild to moderate eczema.

"What we ultimately found was that if you ask these kids every six months if their disease was active, or if they're using medicines, most of them, up until they're in their twenties--which is as far as we can go so far--still notice that they have persistent disease," said Margolis.

At age 20, fewer than 20% of patients reported being symptom-free in the last six months. Based on his findings, Margolis said in a majority of cases, eczema appears to be a lifelong condition--and should be approached that way by physicians and kids and their parents. Fortunately, topical skin creams are effective treatments for most patients.