In this issue of JAMA Dermatology, Margolis et al1 report on the natural history of mild to moderate atopic dermatitis (AD) in children and adolescents. They examined data from the Pediatric Eczema Elective Registry (PEER), which is a prospective, 10-year observational registry that included 22 550 person-years of observation. The study included 2416 patients with at least 5 years of follow-up, which allowed for longitudinal assessment of AD symptoms over a substantial time period. Diagnosis of AD was made at baseline by a dermatologist, allergist, or pediatrician at enrollment. Longitudinal follow-up using surveys by mail was performed at 6-month intervals. The survey had a 70% response rate, which is considered very good for mail-based surveys. The study did not use random, population-based sampling. Nevertheless, participants resided in virtually all states and districts, with a preponderance in the eastern half of the United States and California.