Although it used to be thought that the majority of children with atopic dermatitis, or eczema, “outgrew” the condition, a growing body of evidence suggests otherwise and that, rather, many continue to experience symptoms into late adolescence and even adulthood. “Thus, longitudinal control and persistence is an important outcome to study,” explains Joy Wan, MD, MSCE. “However, it is difficult to predict the future course of disease for any given child, so understanding the patient and disease characteristics that may be associated with more severe and persistent atopic dermatitis over time is informative.”

For a study published in the Journal of the American Academy of Dermatology, Dr. Wan and colleagues examined whether the disease trajectories of children with atopic dermatitis might vary by the timing of onset of their atopic dermatitis. “If early onset atopic dermatitis differed from late onset disease with respect to disease activity over time, then the age of disease onset might be a helpful predictor of longitudinal disease control,” Dr Wan adds. The researchers examined how age at disease onset influenced the trajectory of disease among a national registry of more than 8,000 children with atopic dermatitis who completed surveys every 6 months on their disease control and medication use for up to 10 years.

“We found that older age at atopic dermatitis onset was associated with better disease control and less persistent disease over time, with a 7%-16% lower odds of poorer control and persistence for each additional year of age at disease onset,” says Dr. Wan. “In other words, a child whose atopic dermatitis began at age 10 had 44% lower odds of worse disease control and 75% lower odds of persistent disease over time when compared with a child whose atopic dermatitis began at age 2. These results are adjusted for sociodemographic characteristics and comorbid asthma and seasonal allergies, indicating that the age of disease onset is an independent predictor of disease trajectory. The take-home point is that earlier onset atopic dermatitis is associated with more longstanding and poorly controlled disease over time. By considering this framework of early- or late-onset disease, we can identify patients who may be at greater risk for more longstanding or poorly controlled disease and whom may benefit from more intensive treatment or monitoring.”