Eczema is a common skin disease that often begins in childhood. It's characterized by a dry, itchy, and red rash.  Most babies grow out of eczema by their fifth birthday, but a new study finds for some, the symptoms can last into their 20s, or even longer.

"Often the question is when is it going to go away? The truth of the matter is that it's probably something that the child and the family therefore are going to struggle with taking care of being times when it's better, worse, not just in childhood, but perhaps throughout life," explained Cleveland Clinic Dermatologist Jennifer Lucas, who did not take part in the study.

University of Pennsylvania researchers followed more than 7,000 children with a history of eczema. They found that from age 2 to 26 more than 80 percent of them had eczema symptoms or were using a medication to treat the condition.

In fact, it was not until age 20 that 50 percent of the study's participants had at least one six-month period free of symptoms and treatment.

Researchers say the results demonstrate how childhood eczema can easily persist into a person's 20s, so physicians should prepare children and their parents for this potentially lifelong battle.

Lucas agrees and adds parents should not let recurrent skin problems go untreated.

"If you see that there is a skin condition -- a rash that is not getting better or something that comes and goes, or your child just seems really itchy and uncomfortable it's certainly something to come to the dermatologist and have us take a look at it because it can be a problem that lasts for a long time and can certainly make your child very uncomfortable," advised Lucas.

Read more about this study in the journal JAMA Dermatology.