Risk of developing asthma in young children with atopic eczema: a systematic review.

Abstract

It is commonly believed that the majority of infants and young children with early atopic eczema will develop asthma in later childhood. This belief is mainly based on cross-sectional population studies. Recent evidence suggests a more complex relationship between early eczema and asthma. This systematic review was conducted to assess the risk of developing asthma in children with atopic eczema during the first 4 years of life. A sensitive search was performed to identify all prospective cohort studies on the topic. By pooling the eligible reports, we calculated the risk of developing asthma at 6 years of age or older in children with atopic eczema in the first 4 years of life. Thirteen prospective cohort studies were included, with 4 representing birth cohort studies and 9 representing eczema cohort studies. The pooled odds ratio for the risk of asthma after eczema, compared with children without eczema, in birth cohort studies was 2.14 (95% CI, 1.67-2.75). The prevalence of asthma at the age of 6 years in eczema cohort studies was 35.8% (95% CI, 32.2% to 39.9%) for inpatients and 29.5% (95% CI, 28.2% to 32.7%) for a combined group of inpatients and outpatients. Although there is an increased risk of developing asthma after eczema in early childhood, only 1 in every 3 children with eczema develops asthma during later childhood. This is lower than previously assumed. Our results may have important consequences for counseling patients with atopic eczema and their parents.