Children with eczema or atopic dermatitis continue to suffer from itchy, red skin in their 20s, a new study reported.

The study, conducted by researchers at University of Pennsylvania Perelman School of Medicine, Philadelphia, and colleagues, shows that contrary to popular belief, eczema is a long-lasting disease. Children with atopic dermatitis have symptoms of the disease well into adulthood.

"It is generally thought that eczema resolves as young children get older. This study, however, followed the natural course of the disease over long periods of time and discovered that symptoms may persist longer than previously thought, lasting at least into the second decade of life or longer," said Dr. Joshua Zeichner, at the department of dermatology at Mount Sinai Hospital in New York City, according to HealthDay.

Eczema is a term used for several kinds of skin swellings. The condition, also called dermatitis, isn't dangerous. Symptoms of the disease include red, itchy and swollen skin. Atopic dermatitis (AD) is a common type of eczema and is characterized by dry and itchy skin. AD generally affects children and teens. The condition is usually seen in children with familial history of hay fever or asthma.

The data for the study came from 7,157 children who were part of the Pediatric Eczema Elective Registry (PEER). On an average, children were just two years old when the symptoms of eczema began.

The study team found that at every age, about 80 percent of the participants had symptoms of eczema or were using medication for the disease.

During a five-year follow up period, researchers noticed that some 64 percent of patients never had a single six-month stretch without the condition. Around 50 percent of the participants had, by age 20, experienced at least one break in eczema symptoms.

"Based on our findings, it is probable that AD does not fully resolve in most children with mild to moderate symptoms. Physicians who treat children with mild to moderate AD should tell children and their caregivers that AD is a lifelong illness with periods of waxing and waning skin problems," authors wrote, according to a press release.

The study is published in the journal JAMA Dermatology.