Clinical features of atopic dermatitis at two years of age: a prospective, population-based case-control study.

While atopic dermatitis (AD) usually presents early in life, few prospective studies focus on young children with AD. The objective of this study was to characterize, phenotypically and prospectively, young children with AD. From a community birth cohort of 2,256 children, consecutive children with AD (n = 221) were followed to 2 years of age, when they were re-examined and screened for atopic sensitization (skin-prick test to foods; Phadiatop). Ninety-nine controls were also examined. AD debuted during the first year in 88% of cases. At the 2-year examination, when the children had already undergone topical treatment, 157/221 (71%) had ongoing eczema ranging among mild (45%), moderate (53%) and severe (2%). Airway problems indicating asthma had occurred in 9% of cases and 6% of controls (not significant), and allergic rhinoconjunctivitis in 5% and 0%, respectively (p<0.05). The skin-prick test to common food allergens was positive in 27% of cases and Phadiatop was positive in 15%. In 67% both tests were negative. Eczema severity did not differ between sensitized and non-sensitized children. Positive Phadiatop was more common in boys than in girls with ongoing AD (22% vs 3%, p<0.01), and more boys than girls had ongoing AD (82% vs 59%, p<0.001); otherwise, no differences attributable to gender were found.